To see the other types of publications on this topic, follow the link: Rat liver mitochondria.
Journal articles on the topic 'Rat liver mitochondria'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Rat liver mitochondria.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Shibata, Tatsuya, Toshinari Takahashi, Eio Yamada, Akiko Kimura, Hiroshi Nishikawa, Hiroyoshi Hayakawa, Nobuhiko Nomura, and Junichi Mitsuyama. "T-2307 Causes Collapse of Mitochondrial Membrane Potential in Yeast." Antimicrobial Agents and Chemotherapy 56, no. 11 (September 4, 2012): 5892–97. http://dx.doi.org/10.1128/aac.05954-11.
Full textAbstract:
ABSTRACTT-2307, an arylamidine compound, has been previously reported to have broad-spectrumin vitroandin vivoantifungal activities against clinically significant pathogens, includingCandidaspecies,Cryptococcus neoformans, andAspergillusspecies, and is now undergoing clinical trials. Here we investigated the mechanism of action of T-2307 using yeast cells and mitochondria isolated from yeast and rat liver. Nonfermentative growth ofCandida albicansandSaccharomyces cerevisiaein glycerol medium, in which yeasts relied on mitochondrial respiratory function, was inhibited at 0.001 to 0.002 μg/ml (0.002 to 0.004 μM) of T-2307. However, fermentative growth in dextrose medium was not inhibited by T-2307. Microscopic examination using Mitotracker fluorescent dye, a cell-permeant mitochondrion-specific probe, demonstrated that T-2307 impaired the mitochondrial function ofC. albicansandS. cerevisiaeat concentrations near the MIC in glycerol medium. T-2307 collapsed the mitochondrial membrane potential in mitochondria isolated fromS. cerevisiaeat 20 μM. On the other hand, in isolated rat liver mitochondria, T-2307 did not have any effect on the mitochondrial membrane potential at 10 mM. Moreover, T-2307 had little inhibitory and stimulatory effect on mitochondrial respiration in rat liver mitochondria. In conclusion, T-2307 selectively disrupted yeast mitochondrial function, and it was also demonstrated that the fungal mitochondrion is an attractive antifungal target.
2
Stuhne-Sekalec, Lidija, and Nikola Z. Stanacev. "Mechanism and localization of cardiolipin biosynthesis revisited: evidence for the identical mechanism and different localization in mitochondrial and submitochrondrial membranes isolated from guinea pig and rat liver." Biochemistry and Cell Biology 68, no. 6 (June 1, 1990): 922–35. http://dx.doi.org/10.1139/o90-137.
Full textAbstract:
The mechanism of cardiolipin (diphosphatidylglycerol) biosynthesis was examined in mitochondria and outer and inner mitochondrial membranes prepared from guinea pig and rat livers to determine whether this formation from phosphatidylglycerol was absolutely dependent on cytidinediphosphodiglyceride, as previously reported for intact mitochondria. Experimental results confirmed that the biosynthesis of cardiolipin, from the membrane-bound radioactive phosphatidylglycerol in intact mitochondria isolated from guinea pig and rat liver, was absolutely dependent on CDP-diglycerides and required the addition of divalent cations. Furthermore, the same mechanism for the biosynthesis of cardiolipin was operational in the outer and inner mitochondrial membranes. This biosynthesis was associated with both the outer and inner mitochondrial membranes prepared from guinea pig liver, but only with the inner mitochondrial membranes prepared from rat liver. The release of radioactive glycerol was also measured, but the amount obtained did not satisfy the stoichiometric requirement for CDP-diglyceride-independent biosynthesis of cardiolipin from 2 mol of phosphatidylglycerol with the liberation of 1 mol of glycerol. Therefore, it was concluded that this mechanism is not involved in the biosynthesis of cardiolipin in mitochondrial and submitochondrial membranes prepared from guinea pig and rat liver.Key words: mitochondria, outer mitochondrial membranes, inner mitochondrial membranes, cardiolipin, biosynthesis.
3
Azain, M. J., and J. A. Ontko. "An explanation for decreased ketogenesis in the liver of the obese Zucker rat." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 257, no. 4 (October 1, 1989): R822—R828. http://dx.doi.org/10.1152/ajpregu.1989.257.4.r822.
Full textAbstract:
These studies were undertaken to further characterize and explain the differences in hepatic fatty acid metabolism between lean and obese Zucker rats. It was shown that the rate of palmitate or octanoate oxidation and the inhibition of palmitate oxidation by malonyl CoA in mitochondria isolated from lean and obese Zucker rats were similar. Cytochrome oxidase activity was similar in lean and obese rat livers. It was found that the addition of cytosol from the obese rat liver inhibited palmitate oxidation by 20-30% in mitochondria isolated from lean or obese rat livers and thus reproduced the conditions observed in the intact cell. Increased concentrations of metabolites such as malonyl CoA and glycerophosphate in the liver of the obese rat are likely contributors to this inhibitory effect. These results are extrapolated to the intact cell and suggest that decreased hepatic fatty acid oxidation in the obese rat can be accounted for by cytosolic influences on the mitochondria. The decreased rate of fatty acid oxidation observed in the intact hepatocyte or perfused liver cannot be explained by a defect in the capacity of mitochondria to oxidize substrate or by a decrease in mitochondrial number in the obese rat liver.
4
Goudarzi, M., H. Kalantari, and M. Rezaei. "Glyoxal toxicity in isolated rat liver mitochondria." Human & Experimental Toxicology 37, no. 5 (June 22, 2017): 532–39. http://dx.doi.org/10.1177/0960327117715900.
Full textAbstract:
Glyoxal is a physiological metabolite formed by lipid peroxidation, ascorbate autoxidation, oxidative degradation of glucose, and degradation of glycated proteins. Glyoxal has been linked to oxidative stress and can cause a number of cellular damages, including covalent modification of amino and thiol groups of proteins to form advanced glycation end products. However, the mechanism of glyoxal toxicity has not been fully understood. In this study, we have focused on glyoxal toxicity in isolated rat liver mitochondria. Isolated mitochondria (0.5 mg protein per milliliter) were prepared from the Wistar rat liver using differential centrifugation and incubated with various concentrations of glyoxal (1, 2.5, 5, 7.5, and 10 mM) for 30 min. The activity of mitochondrial complex II was determined by measurement of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) conversion. The mitochondrial membrane potential (MMP), lipid peroxidation (MDA), reactive oxygen species (ROS) formation, glutathione (GSH) content, and protein carbonylation were also assessed. After an incubation of isolated liver mitochondria with glyoxal, disrupted electron transport chain, increased mitochondrial ROS formation, lipid peroxidation, mitochondrial membrane damage, GSH oxidation, and protein carbonylation ensued as compared to the control group ( p < 0.05). Glyoxal toxicity in isolated rat liver mitochondria was dose-dependent. In conclusion, glyoxal impaired the electron transport chain, which is the cause of increased ROS and MDA production, depletion of GSH, and disruption of MMP. Mitotoxicity of glyoxal might be related to the pathomechanisms involved in diabetes and its complications.
5
Heine, U. I., J. K. Burmester, K. C. Flanders, D. Danielpour, E. F. Munoz, A. B. Roberts, and M. B. Sporn. "Localization of transforming growth factor-beta 1 in mitochondria of murine heart and liver." Cell Regulation 2, no. 6 (June 1991): 467–77. http://dx.doi.org/10.1091/mbc.2.6.467.
Full textAbstract:
Using both electron microscopic immunohistochemistry and cell fractionation techniques, we show that transforming growth factor-beta 1 (TGF-beta 1) is found in mitochondria of rat and mouse cardiac myocytes and rat hepatocytes. Four different polyclonal antibodies, raised against various epitopes encompassing the mature portion of the TGF-beta 1 molecule as well as the pro-region of its precursor, were used for the electron microscopy studies. The localization of TGF-beta 1 in mitochondria was confirmed by detection of the native peptide in mitochondria isolated from rat heart and liver; the majority of native TGF-beta 1 found in liver homogenates was recovered in highly pure mitochondrial fractions. The functional role of TGF-beta in the mitochondrion is unknown at present.
6
Freeman, M., and E. H. Mangiapane. "Translocation to rat liver mitochondria of phosphatidate phosphohydrolase." Biochemical Journal 263, no. 2 (October 15, 1989): 589–95. http://dx.doi.org/10.1042/bj2630589.
Full textAbstract:
When a particle-free supernatant fraction from rat liver was incubated at 37 degrees C with mitochondria and oleate, some of the enzyme phosphatidate phosphohydrolase (PAP), initially present in the particle-free supernatant, was recovered, after the incubation, bound to mitochondria. This translocation of PAP from cytosol to mitochondria was stimulated by oleate or palmitate in a similar fashion to the stimulation of translocation of PAP to endoplasmic reticulum [Martin-Sanz, Hopewell & Brindley (1984) FEBS Lett. 175, 284-288]. Translocation of PAP from particle-free supernatant to a partially purified mitochondrial-outer-membrane preparation was also stimulated by oleate. More PAP was bound to a mitochondrial-outer-membrane fraction washed in 0.5 M-NaCl before resuspension in sucrose than to a sucrose-washed mitochondrial-outer-membrane preparation. In contrast, washing of microsomal membranes in 0.5 M-NaCl did not enhance the binding of PAP to these membranes. PAP also binds to phosphatidate-loaded mitochondria or microsomes (microsomal fractions). In the experimental system employed, more PAP bound to mitochondria loaded with phosphatidate than to microsomes loaded with phosphatidate. The results are discussed in relation to the role of mitochondrial phosphatidate in liver lipid metabolism.
7
Quant, P. A., P. K. Tubbs, and M. D. Brand. "Treatment of rats with glucagon or mannoheptulose increases mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase activity and decreases succinyl-CoA content in liver." Biochemical Journal 262, no. 1 (August 15, 1989): 159–64. http://dx.doi.org/10.1042/bj2620159.
Full textAbstract:
1. The activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (EC 4.1.3.5) in extracts of rapidly frozen rat livers was doubled in animals treated in various ways to increase ketogenic flux. 2. Some 90% of the activity measured was mitochondrial, and changes in mitochondrial activity dominated changes in total enzyme activity. 3. The elevated HMG-CoA synthase activities persisted throughout the isolation of liver mitochondria. 4. Intramitochondrial succinyl-CoA content was lower in whole liver homogenates and in mitochondria isolated from animals treated with glucagon or mannoheptulose. 5. HMG-CoA synthase activity in mitochondria from both ox and rat liver was negatively correlated with intramitochondrial succinyl-CoA levels when these were manipulated artificially. Under these conditions, the differences between mitochondria from control and hormone-treated rats were abolished. 6. These findings show that glucagon can decrease intramitochondrial succinyl-CoA concentration, and that this in turn can regulate mitochondrial HMG-CoA synthase. They support the hypothesis that the formation of ketone bodies from acetyl-CoA may be regulated by the extent of succinylation of mitochondrial HMG-CoA synthase.
8
Beggs, M., and P. J. Randle. "Activity of branched-chain 2-oxo acid dehydrogenase complex in rat liver mitochondria and in rat liver." Biochemical Journal 256, no. 3 (December 15, 1988): 929–34. http://dx.doi.org/10.1042/bj2560929.
Full textAbstract:
Four mitochondrial marker enzymes were used to show that: (1) high-protein (24%) diet increased the rat liver concentration and content of total branched-chain 2-oxo acid dehydrogenase complex (BCDC) by 31% by increasing mitochondrial specific activity of BCDC; (2) starvation increased the liver concentration of BCDC by 25% by decreasing liver weight; the liver content of mitochondria and the mitochondrial specific activity of BCDC were unchanged; (3) protein-free diet decreased rat liver BCDC concentration and content by 20%, by decreasing the liver concentration and content of mitochondria. Protein-free diet increased liver mitochondrial specific activities of L-glutamate, 2-oxoglutarate and NAD-isocitrate dehydrogenases. The validity of a mitochondrial method for the determination of the liver concentration of BCDC and the percentage in the active form in vivo is confirmed, and improvements are described. The experimental basis of criticisms of its use in this regard by Zhang, Paxton, Goodwin, Shimomura & Harris [(1987) Biochem. J. 246, 625-631] was not confirmed. The finding by Harris, Powell, Paxton, Gillim & Nagae [(1985) Arch. Biochem. Biophys. 243, 542-555], that starvation has no effect on the percentage of BCDC in the active form in rat liver, is confirmed.
9
Espinal, J., P. A. Patston, H. R. Fatania, K. S. Lau, and P. J. Randle. "Purification and properties of a protein activator of phosphorylated branched-chain 2-oxo acid dehydrogenase complex." Biochemical Journal 225, no. 2 (January 15, 1985): 509–16. http://dx.doi.org/10.1042/bj2250509.
Full textAbstract:
The protein activator of phosphorylated branched-chain 2-oxo acid dehydrogenase complex was purified greater than 1000-fold from extracts of rat liver mitochondria; the specific activity was greater than 1000 units/mg of protein (1 unit gives half-maximum re-activation of 10 munits of phosphorylated complex). Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis gave two bands (Mr 47700 and 35300) indistinguishable from the alpha- and beta-subunits of the branched-chain dehydrogenase component of the complex. On gel filtration (Sephacryl S-300), apparent Mr was 190000. This and other evidence suggests that activator protein is free branched-chain dehydrogenase; this conclusion is provisional until identical amino acid composition of the subunits has been demonstrated. Activator protein (i.e. free branched-chain dehydrogenase) was inhibited (up to 30%) by NaF, whereas branched-chain complex was not inhibited. There was no convincing evidence for interconvertible active and inactive forms of activator protein in rat liver mitochondria. Activator protein was detected in mitochondria from liver (ox, rabbit and rat) and kidney (ox and rat), but not in rat heart or skeletal-muscle mitochondria. In rat liver mitochondrial extracts, branched-chain complex sedimented with the mitochondrial membranes, whereas activator protein remained in the supernatant. Activator protein re-activated phosphorylated (inactive) particulate complex from rat liver mitochondria, but it did not activate dephosphorylated complex. Liver and kidney, but not muscle, mitochondria apparently contain surplus free branched-chain dehydrogenase, which is bound by the complex with lower affinity than is the branched-chain dehydrogenase intrinsic to the complex. It is suggested that this functions as a buffering mechanism to maintain branched-chain complex activity in liver and kidney mitochondria.
10
Carlenor, Elisabeth, Vigg Joste, B. Dean Nelson, and Jan Rydström. "Cell-free translation of mitochondrial nicotinamide nucleotide transhydrogenase." Bioscience Reports 5, no. 6 (June 1, 1985): 483–90. http://dx.doi.org/10.1007/bf01116947.
Full textAbstract:
Mammalian nicotinamide nucleotide transhydrogenase is translated as a 5000 daltons larger molecular weight precursor in a cell-free system programmed with rat liver polysomes. The mature rat liver enzyme had the same molecular weight as the purified beef heart enzyme, 115 000 daltons. The precursor was not processed in vitro by liver mitochondria or by a rat liver mitochondrial matrix fraction, nor did it appear to bind to mitochondria. In contrast, pre-FeS protein of the cytochrome bc1 complex was processed in the same samples by both mitochondria and matrix, suggesting an important difference in the processing mechanisms or in the efficiency of processing of the two precursors.
11
Villalobos-Molina, Rafael, J. Pablo Pardo, Alfredo Saavedra-Molina, and Enrique Piña. "Accumulation of D-arginine by rat liver mitochondria." Biochemistry and Cell Biology 65, no. 12 (December 1, 1987): 1057–63. http://dx.doi.org/10.1139/o87-138.
Full textAbstract:
The permeability of the inner mitochondrial membrane from rat liver to D-arginine was studied. By using safranin as a probe of the membrane potential, depolarization of energized liver mitochondria occurred in a dose-dependent fashion starting at 3.3 mmol/L of D- or DL-arginine. When ethidium bromide fluorescence was employed, a decrease in the membrane potential due to D- or DL-arginine was observed. A parallel significant change in succinate-induced respiration in rat liver mitochondria was found in response to osmotic swelling in 125 mmol/L of D-arginine salts. L-Arginine, L-glutamine, L-asparagine, L-ornithine, D-ornithine, and L-lysine did not modify the membrane potential at the concentrations tested. D-Arginine was not transformed into citrulline, but 1.0 mmol/L of the D-amino acid inhibited, by 42%, the state 3 of mitochondrial respiration using succinate as substrate. When D-arginine was used in combination with nigericin, a 40% inhibition of mitochondrial respiration in state 3 was recorded with succinate and with glutamate–malate as substrates.
12
Ferenchuk, Ye O., and I. V. Gerush. "Glutathione influence on energy metabolism in rat liver mitochondria under experimental nephropathy." Ukrainian Biochemical Journal 91, no. 3 (May 15, 2019): 19–24. http://dx.doi.org/10.15407/ubj91.03.019.
Full text
13
Umida, Yusupova, Mamatova Zulaykho, Dzhabbarova Gulchehra, Tukhtaeva Feruza, and Almatov Karim. "Influence Of Galangin On Respiration And Oxidative Phosphorylation Of Rat Liver Mitochondria." American Journal of Agriculture and Biomedical Engineering 02, no. 06 (June 23, 2020): 14–23. http://dx.doi.org/10.37547/tajabe/volume02issue06-02.
Full text
14
Scislowski, P. W., A. R. Foster, and M. F. Fuller. "Regulation of oxidative degradation of l-lysine in rat liver mitochondria." Biochemical Journal 300, no. 3 (June 15, 1994): 887–91. http://dx.doi.org/10.1042/bj3000887.
Full textAbstract:
The generation of 14CO2 from [1-14C]lysine by hepatic mitochondria through the saccharopine pathway is controlled by intramitochondrial concentrations of lysine, 2-oxoglutarate and NADPH. Mitochondria, isolated from rats pre-treated with glucagon, exhibited higher activities of L-lysine: 2-oxoglutarate reductase, saccharopine dehydrogenase and 2-aminoadipate aminotransferase. The flux through this pathway is stimulated in liver mitochondria after glucagon treatment. Multiple regulation of lysine oxidation in liver mitochondria confirms a complex mechanism of ‘mitochondrial activation’ by glucagon.
15
Bailey, Shannon M., Gloria Robinson, Anita Pinner, Laura Chamlee, Elena Ulasova, Melissa Pompilius, Grier P. Page, et al. "S-adenosylmethionine prevents chronic alcohol-induced mitochondrial dysfunction in the rat liver." American Journal of Physiology-Gastrointestinal and Liver Physiology 291, no. 5 (November 2006): G857—G867. http://dx.doi.org/10.1152/ajpgi.00044.2006.
Full textAbstract:
An early event that occurs in response to alcohol consumption is mitochondrial dysfunction, which is evident in changes to the mitochondrial proteome, respiration defects, and mitochondrial DNA (mtDNA) damage. S-adenosylmethionine (SAM) has emerged as a potential therapeutic for treating alcoholic liver disease through mechanisms that appear to involve decreases in oxidative stress and proinflammatory cytokine production as well as the alleviation of steatosis. Because mitochondria are a source of reactive oxygen/nitrogen species and a target for oxidative damage, we tested the hypothesis that SAM treatment during alcohol exposure preserves organelle function. Mitochondria were isolated from livers of rats fed control and ethanol diets with and without SAM for 5 wk. Alcohol feeding caused a significant decrease in state 3 respiration and the respiratory control ratio, whereas SAM administration prevented these alcohol-mediated defects and preserved hepatic SAM levels. SAM treatment prevented alcohol-associated increases in mitochondrial superoxide production, mtDNA damage, and inducible nitric oxide synthase induction, without a significant lessening of steatosis. Accompanying these indexes of oxidant damage, SAM prevented alcohol-mediated losses in cytochrome c oxidase subunits as shown using blue native PAGE proteomics and immunoblot analysis, which resulted in partial preservation of complex IV activity. SAM treatment attenuated the upregulation of the mitochondrial stress chaperone prohibitin. Although SAM supplementation did not alleviate steatosis by itself, SAM prevented several key alcohol-mediated defects to the mitochondria genome and proteome that contribute to the bioenergetic defect in the liver after alcohol consumption. These findings reveal new molecular targets through which SAM may work to alleviate one critical component of alcohol-induced liver injury: mitochondria dysfunction.
16
ROUSSEL, Damien, Jean-François DUMAS, Gilles SIMARD, Yves MALTHIÈRY, and Patrick RITZ. "Kinetics and control of oxidative phosphorylation in rat liver mitochondria after dexamethasone treatment." Biochemical Journal 382, no. 2 (August 24, 2004): 491–99. http://dx.doi.org/10.1042/bj20040696.
Full textAbstract:
The present investigation was undertaken in order to evaluate the contributions of ATP synthesis and proton leak reactions to the rate of active respiration of liver mitochondria, which is altered following dexamethasone treatment (1.5 mg/kg per day for 5 days). We applied top-down metabolic control analysis and its extension, elasticity analysis, to gain insight into the mechanisms of glucocorticoid regulation of mitochondrial bioenergetics. Liver mitochondria were isolated from dexamethasone-treated, pair-fed and control rats when in a fed or overnight fasted state. Injection of dexamethasone for 5 days resulted in an increase in the fraction of the proton cycle of phosphorylating liver mitochondria, which was associated with a decrease in the efficiency of the mitochondrial oxidative phosphorylation process in liver. This increase in proton leak activity occurred with little change in the mitochondrial membrane potential, despite a significant decrease in the rate of oxidative phosphorylation. Regulation analysis indicates that mitochondrial membrane potential homoeostasis is achieved by equal inhibition of the mitochondrial substrate oxidation and phosphorylation reactions in rats given dexamethasone. Our results also suggest that active liver mitochondria from dexamethasone-treated rats are capable of maintaining phosphorylation flux for cellular purposes, despite an increase in the energetic cost of mitochondrial ATP production due to increased basal proton permeability of the inner membrane. They also provide a complete description of the effects of dexamethasone treatment on liver mitochondrial bioenergetics.
17
Jois, M., H. S. Ewart, and J. T. Brosnan. "Regulation of glycine catabolism in rat liver mitochondria." Biochemical Journal 283, no. 2 (April 15, 1992): 435–39. http://dx.doi.org/10.1042/bj2830435.
Full textAbstract:
1. The catabolism of glycine was studied in isolated rat liver mitochondria by measuring release of 14CO2 from [1-14C]-glycine. Incubation of mitochondria in a medium containing 0.5 microM free Ca2+ resulted in an 8-fold increase in the rate of degradation of glycine. Intraperitoneal injection of glucagon (33 or 100 micrograms/100 g body wt.) 25 min before killing of rats also resulted in a 3-fold or 10-fold (depending on dosage) increase in the rate of catabolism of glycine. 2. Both the stimulation by free Ca2+ and that by injection of glucagon in vivo were dependent on phosphate in the incubation medium. This requirement for phosphate was specific, as replacement of phosphate by other permeant anions such as thiocyanate and acetate did not permit the stimulation. The phosphate-dependent stimulation of glycine catabolism by Ca2+ was also evident when mitochondria were incubated in the absence of K+. 3. Mitochondria isolated from rats previously injected with glucagon showed elevated rates of degradation of glycine even in the presence of rotenone, provided that regeneration of NAD+ was affected by providing acetoacetate. 4. Hypo-osmolarity of the medium markedly stimulated the rate of degradation of glycine by mitochondria. Although hypo-osmolarity-induced stimulation of glycine degradation was accompanied by parallel changes in mitochondrial matrix volume, no measurable changes in matrix volume were observed in mitochondria stimulated either by free Ca2+ (0.5 microM) or by injection of glucagon in vivo. Furthermore, Ca2+ stimulated glycine decarboxylation in mitochondria exposed to either hyper-osmolar (410 mosmol) or hypo-osmolar (210 mosmol) conditions. Although hyper-osmolarity decreased and hypo-osmolarity increased matrix volume, stimulation of glycine degradation by Ca2+ was not associated with any further changes in matrix volume. 5. These data demonstrate that the regulation of hepatic glycine oxidation by glucagon and by free Ca2+ is largely independent of changes in mitochondrial matrix volume.
18
Mezera, Vojtech, Rene Endlicher, Otto Kucera, Ondrej Sobotka, Zdenek Drahota, and Zuzana Cervinkova. "Effects of Epigallocatechin Gallate on Tert-Butyl Hydroperoxide-Induced Mitochondrial Dysfunction in Rat Liver Mitochondria and Hepatocytes." Oxidative Medicine and Cellular Longevity 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/7573131.
Full textAbstract:
Epigallocatechin gallate (EGCG) is a green tea antioxidant with adverse effects on rat liver mitochondria and hepatocytes at high doses. Here, we assessed whether low doses of EGCG would protect these systems from damage induced by tert-butyl hydroperoxide (tBHP). Rat liver mitochondria or permeabilized rat hepatocytes were pretreated with EGCG and then exposed to tBHP. Oxygen consumption, mitochondrial membrane potential (MMP), and mitochondrial retention capacity for calcium were measured. First, 50 μM EGCG or 0.25 mM tBHP alone increased State 4 Complex I-driven respiration, thus demonstrating uncoupling effects; tBHP also inhibited State 3 ADP-stimulated respiration. Then, the coexposure to 0.25 mM tBHP and 50 μM EGCG induced a trend of further decline in the respiratory control ratio beyond that observed upon tBHP exposure alone. EGCG had no effect on MMP and no effect, in concentrations up to 50 μM, on mitochondrial calcium retention capacity. tBHP led to a decline in both MMP and mitochondrial retention capacity for calcium; these effects were not changed by pretreatment with EGCG. In addition, EGCG dose-dependently enhanced hydrogen peroxide formation in a cell- and mitochondria-free medium.Conclusion. Moderate nontoxic doses of EGCG were not able to protect rat liver mitochondria and hepatocytes from tBHP-induced mitochondrial dysfunction.
19
Wu, L. N. Y., I. M. Lubin, and R. R. Fisher. "Import of rat liver mitochondrial transhydrogenase." Biochemical Journal 252, no. 3 (June 15, 1988): 833–36. http://dx.doi.org/10.1042/bj2520833.
Full textAbstract:
The biosynthesis of pyridine dinucleotide transhydrogenase has been studied in isolated rat hepatocytes and in a rabbit reticulocyte-lysate translation system supplemented with either intact isolated rat liver mitochondria or the soluble matrix fraction from isolated mitochondria. In intact hepatocytes, the transhydrogenase precursor was short-lived in the cytosol and was efficiently imported into the membranous fraction. When the cell-free translation mixture was incubated with intact mitochondria, the transhydrogenase precursor was processed to the mature form, to an extent that depended on the amount of added mitochondria. Incubation of the translation mixture with the soluble mitochondria matrix fraction converted the precursor to a mature-sized protein with 75% efficiency, this being blocked by various proteinase inhibitors such as EDTA, 1,10-phenanthroline and leupeptin.
20
Flis, Damian Jozef, Robert Antoni Olek, Jan Jacek Kaczor, Ewa Rodziewicz, Malgorzata Halon, Jedrzej Antosiewicz, Michal Wozniak, Rosita Gabbianelli, and Wieslaw Ziolkowski. "Exercise-Induced Changes in Caveolin-1, Depletion of Mitochondrial Cholesterol, and the Inhibition of Mitochondrial Swelling in Rat Skeletal Muscle but Not in the Liver." Oxidative Medicine and Cellular Longevity 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/3620929.
Full textAbstract:
The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1) plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise.
21
de BARI, Lidia, Anna ATLANTE, Nicoletta GUARAGNELLA, Giovanni PRINCIPATO, and Salvatore PASSARELLA. "d-Lactate transport and metabolism in rat liver mitochondria." Biochemical Journal 365, no. 2 (July 15, 2002): 391–403. http://dx.doi.org/10.1042/bj20020139.
Full textAbstract:
In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize d-lactate. We found the following: (1) externally added d-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation) = 2] and membrane potential (Δψ) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by α-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (d-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate d-lactate traffic across the mitochondrial inner membrane: the d-lactate/H+ symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the d-lactate/oxoacid antiporter (which mediates both the d-lactate/pyruvate and d-lactate/oxaloacetate exchanges) and d-lactate/malate antiporter studied by monitoring photometrically the appearance of the d-lactate counteranions outside mitochondria. The d-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the Vmax values and in the inhibition and pH profiles and were shown to regulate mitochondrial d-lactate metabolism in vitro. The d-lactate translocators and the d-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for d-lactate-dependent gluconeogenesis.
22
Calamita, Giuseppe, Maria Moreno, Domenico Ferri, Elena Silvestri, Patrizia Roberti, Luigi Schiavo, Patrizia Gena, Maria Svelto, and Fernando Goglia. "Triiodothyronine modulates the expression of aquaporin-8 in rat liver mitochondria." Journal of Endocrinology 192, no. 1 (January 2007): 111–20. http://dx.doi.org/10.1677/joe-06-0058.
Full textAbstract:
The recent identification of aquaporin-8 (AQP8), an aquaporin (AQP) channel permeable to water and ammonia, in the inner membrane (IMM) of rat liver mitochondria suggested a role for such AQP in the hydration state and the metabolic function of mitochondria. Since thyroid hormone triiodothyronine (T3) is known to modulate both the shape and the metabolic activities of liver mitochondria, it was interesting to investigate the expression and distribution of AQP8 as well as the osmotic water permeability of the IMM in liver mitochondria from rats in different thyroid states. By semi-quantitative reverse transcriptase (RT)-PCR, when compared with the euthyroid counterpart, the levels of hepatic AQP8 mRNA significantly increased in the hypothyroid state, whereas they were strongly decreased after administration of T3. A similar pattern was seen at the protein level by immunoblotting mitochondrial membranes. The upregulation of mitochondrial AQP8 in the hypothyroid liver was confirmed by immunogold electron microscopy. Stopped-flow light scattering with IMM vesicles showed no significant differences in terms of osmotic water permeability among the IMMs in the various thyroid states. Overall, our data indicate that the T3 modulation of the AQP8 gene is a rapid downregulation of transcription. Modulation of hepatic AQP8 expression may be relevant to the regulation of mitochondrial metabolism by thyroid hormones.
23
Navarro, Ana, and Alberto Boveris. "Rat brain and liver mitochondria develop oxidative stress and lose enzymatic activities on aging." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 287, no. 5 (November 2004): R1244—R1249. http://dx.doi.org/10.1152/ajpregu.00226.2004.
Full textAbstract:
The mitochondrial mass of rat brain and liver remained unchanged on aging in young adults, old adults, and senescent animals (28, 60, and 92 wk of age); the values were 15–17 and 29–31 mg protein/g for brain and liver, respectively. The whole aging process was associated with an increased content of the oxidation products, thiobarbituric acid-reactive substances and protein carbonyls, by 61–69% in brain and 36–45% in liver, respectively. The activities of critical enzymes for mitochondrial function, mitochondrial nitric oxide synthase, Mn-superoxide dismutase, complex I, and complex IV, decreased progressively during aging with activity losses of 73, 37, 29, and 28%, respectively, in the brain and 47, 46, 30, and 24% in the liver of senescent rats compared with young adults. Brain mitochondria isolated from aged rats showed increased mitochondrial fragility, as assayed by mitochondrial marker enzyme activities in the postmitochondrial supernatant, and increased volume and water permeability, as assayed by light scattering. Liver mitochondria isolated from young and old rats did not show differences in fragility and water permeability. A subpopulation of brain mitochondria with increased size and fragility was differentiated in aging rats, whereas liver showed a homogeneous mitochondrial population.
24
Al-Nasser, I., and M. Crompton. "The reversible Ca2+-induced permeabilization of rat liver mitochondria." Biochemical Journal 239, no. 1 (October 1, 1986): 19–29. http://dx.doi.org/10.1042/bj2390019.
Full textAbstract:
Rat liver mitochondria became permeabilized to sucrose according to an apparent first-order process after accumulating 35 nmol of Ca2+/mg of protein in the presence of 2.5 mM-Pi, but not in its absence. A fraction (24-32%) of the internal space remains sucrose-inaccessible. The rate constant for permeabilization to sucrose decreases slightly when the pH is decreased from 7.5 to 6.5, whereas the rate of inner-membrane potential (delta psi) dissipation is markedly increased, which indicates that H+ permeation precedes sucrose permeation. Permeabilization does not release mitochondrial proteins. [14C]Sucrose appears to enter permeabilized mitochondria instantaneously. Chelation of Ca2+ with EGTA restores delta psi and entraps sucrose in the matrix space. With 20 mM-sucrose at the instant of resealing, about 21 nmol of sucrose/mg of protein becomes entrapped. The amount of sucrose entrapped is proportional to the degree of permeabilization. Entrapped sucrose is not removed by dilution of the mitochondrial suspension. Resealed mitochondria washed three times retain about 74% of the entrapped sucrose. In the presence of Ruthenium Red and Ca2+ buffers permeabilized mitochondria reseal only partially with free [Ca2+] greater than 3 microM. [14C]Sucrose enters partially resealed mitochondria continuously with time, despite maintenance of delta psi, in accordance with continued interconversion of permeable and impermeable forms. Kinetic analyses of [14C]sucrose entry indicate two Ca2+-sensitive reactions in permeabilization. This conclusion is supported by the biphasic time courses of resealing and repolarization of permeabilized mitochondria and the acute dependence of the rapid repolarization on the free [Ca2+]. A hypothetical model of permeabilization and resealing is suggested and the potential of the procedure for matrix entrapment of substances is discussed.
25
Akopova, O. V., L. I. Kolchinskaya, and V. I. Nosar Kolchinskaya. "Functional activity of permeability transition pore in energized and deenergized rat liver mitochondria." Ukrainian Biochemical Journal 92, no. 6 (December 24, 2020): 63–76. http://dx.doi.org/10.15407/ubj92.06.063.
Full text
26
LEDUCQ, Nathalie, Marie-Christine DELMAS-BEAUVIEUX, Isabelle BOURDEL-MARCHASSON, Sylvie DUFOUR, Jean-Louis GALLIS, Paul CANIONI, and Philippe DIOLEZ. "Mitochondrial permeability transition during hypothermic to normothermic reperfusion in rat liver demonstrated by the protective effect of cyclosporin A." Biochemical Journal 336, no. 2 (December 1, 1998): 501–6. http://dx.doi.org/10.1042/bj3360501.
Full textAbstract:
The purpose of this study was to test the hypothesis that mitochondrial permeability transition might be implicated in mitochondrial and intact organ dysfunctions associated with damage induced by reperfusion after cold ischaemia. Energetic metabolism was assessed continuously by 31P-NMR on a model system of isolated perfused rat liver; mitochondria were extracted from the livers and studied by using top-down control analysis. During the temperature transition from hypothermic to normothermic perfusion (from 4 to 37 °C) the ATP content of the perfused organ fell rapidly, and top-down metabolic control analysis of damaged mitochondria revealed a specific control pattern characterized by a dysfunction of the phosphorylation subsystem leading to a decreased response to cellular ATP demand. Both dysfunctions were fully prevented by cyclosporin A, a specific inhibitor of the mitochondrial transition pore (MTP). These results strongly suggest the involvement of the opening of MTP in vivo during the transition to normothermia on rat liver mitochondrial function and organ energetics.
27
Dutta, Mousumi, and Goutam Paul. "BISPHENOL A DOSE- AND TIME-DEPENDENTLY INDUCES OXIDATIVE STRESS IN RAT LIVER MITOCHONDRIA EX VIVO." Asian Journal of Pharmaceutical and Clinical Research 11, no. 9 (September 7, 2018): 98. http://dx.doi.org/10.22159/ajpcr.2018.v11i9.26750.
Full textAbstract:
Objective: The probable toxic effects of bisphenol A (BPA) on different physiological functions have been reported in animal models. The role of BPA in mitochondrial oxidative stress has not been reported till date. The present study is aimed to elucidate dose- and time-dependent oxidative stress generation by BPA, respectively, in rat liver mitochondria in ex vivo model. Methods: The incubation mixture of BPA-treated groups containing mitochondria, 50 mM potassium phosphate buffer (pH 7.4), and different concentrations of BPA (20–160 μM/ml) (dissolved in 12% DMSO) in a final volume of 1.0 ml was incubated at 37°C in incubator for different time durations (30 min–2 h). Whereas, the incubation mixture of control group contained DMSO (12%), mitochondria and 50 mM potassium phosphatebuffer (pH 7.4).’ will be replaced by ‘Whereas, the incubation mixture of control group contained the same constituents except BPA. Result: We have observed significant decrease in mitochondrial intactness incubated with BPA in dose- and time-dependent manner under bright field and confocal microscopic study compared to control. Further, we have observed a decrease in mitochondrial reduced glutathione (GSH) content and increase in lipid peroxidation and protein carbonylation levels in dose- and time-dependent manner in BPA-exposed mitochondria. We have found a significant increase in the activity of Mn-superoxide dismutase and decrease in the activities of GSH peroxidase, GSH reductase, pyruvate dehydrogenase, and other three enzymes of Kreb’s cycle dose and time dependently in BPA-exposed mitochondria. The results indicate that exposure to BPA leads to decrease in intactness of mitochondria and increase in oxidative stress in mitochondria isolated from rat liver in a dose- and time-dependent manner. Conclusion: It can be concluded that the incubation of mitochondria isolated from rat liver with BPA, caused oxidative stress-mediated damages in mitochondria in both dose- and time-dependent manners.
28
Mok, Amy Y. P., Gordon E. McDougall, and William C. McMurray. "Comparative studies of CDP-diacylglycerol synthase in rat liver mitochondria and microsomes." Biochemistry and Cell Biology 71, no. 3-4 (March 1, 1993): 183–89. http://dx.doi.org/10.1139/o93-029.
Full textAbstract:
CDP-diacylglycerol for polyglycerophosphatide biogenesis can be synthesized within rat liver mitochondria. Contamination by microsomal membranes cannot account for the CDP-diacylglycerol synthesis found in the mitochondria. Phosphatidic acid from egg lecithin was the best substrate for the synthesis of CDP-diacylglycerol in both subcellular fractions. Concentration curves for CTP and Mg2+ differed for the two subcellular fractions. Microsomal CDP-diacylglycerol synthase was specifically stimulated by the nucleotide GTP; this stimulatory effect by GTP was not observed in the mitochondrial fraction. By comparison, the microsomal enzyme was more sensitive towards sulfhydryl inhibitors than the mitochondrial enzyme. The enzymes could be solubilized from the membrane fractions using 3-[(cholamidopropyl)dimethylammonio]-1-propanesulfonate, and the detergent-soluble activity could be partially restored by addition of phospholipids. Based on the differences in properties, it was concluded that there are two distinct enzyme localizations for CDP-diacylglycerol synthesis in mitochondria and microsomes from rat liver.Key words: CDP-diacylglycerol, synthase, phosphatidic acid, mitochondria, microsomes, solubilization.
29
Dechandt, Carlos Roberto Porto, Tatiane M. Vicentini, Guilherme Pauperio Lanfredi, Rui M. P. Silva-Jr., Enilza Maria Espreafico, José A. Cortes de Oliveira, Vitor Marcel Faça, Norberto Garcia-Cairasco, and Luciane Carla Alberici. "The highly efficient powerhouse in the Wistar audiogenic rat, an epileptic rat strain." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 316, no. 3 (March 1, 2019): R243—R254. http://dx.doi.org/10.1152/ajpregu.00254.2018.
Full textAbstract:
The Wistar audiogenic rat (WAR) is an animal model of tonic-clonic epileptic seizures, developed after genetic selection by sister × brother inbreeding of Wistar rats susceptible to sound stimuli. Although metabolic changes have been described in this strain, nothing is known about its mitochondrial metabolism. Here, we addressed mitochondrial aspects of oxidative phosphorylation, oxidative stress, biogenesis, and dynamics in liver, skeletal muscle, and heart of male WARs and correlating them with physiological aspects of body metabolism. The results showed higher mitochondrial content, respiration rates in phosphorylation and noncoupled states, and H2O2 production in WARs. Liver presented higher content of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) and mammalian target of rapamycin, proteins related to mitochondrial biogenesis. In agreement, isolated liver mitochondria from WARs showed higher respiration rates in phosphorylation state and ADP-to-O ratio, as well as higher content of proteins related to electron transport chain ATP synthase, TCA cycle, and mitochondrial fusion and fission compared with their Wistar counterparts. Mitochondria with higher area and perimeter and more variable shapes were found in liver and soleus from WARs in addition to lower reduced-to-oxidized glutathione ratio. In vivo, WARs demonstrated lower body mass and energy expenditure but higher food and water intake and amino acid oxidation. When exposed to a running test, WARs reached higher speed and resisted for a longer time and distance than their Wistar controls. In conclusion, the WAR strain has mitochondrial changes in liver, skeletal muscle, and heart that improve its mitochondrial capacity of ATP production, making it an excellent rat model to study PGC1α overexpression and mitochondrial function in different physiological conditions or facing pathological challenges.
30
Said, H. M., L. McAlister-Henn, R. Mohammadkhani, and D. W. Horne. "Uptake of biotin by isolated rat liver mitochondria." American Journal of Physiology-Gastrointestinal and Liver Physiology 263, no. 1 (July 1, 1992): G81—G86. http://dx.doi.org/10.1152/ajpgi.1992.263.1.g81.
Full textAbstract:
This study examined the mechanism of biotin uptake by liver mitochondria. Mitochondria were isolated from rat liver by an established procedure and demonstrated normal respiratory control ratios. Uptake of biotin with time at incubation buffer pH 6.1 was rapid and linear and occurred with a distinct "overshoot" phenomenon that peaked at approximately 1 min of incubation. At incubation buffer pH 7.4, however, uptake of biotin with time was significantly slower and no overshoot was observed. Gradual lowering of incubation buffer pH from 7.9 to 6.1 caused a similar pattern of increase in uptake of low (0.024 microM) and high (8 and 30 microM) concentrations of biotin. At incubation buffer pH 6.1 and 7.4, uptake of biotin as a function of concentration (0.012-30 microM) was linear and occurred at rates of 3.62 and 1.90 pmol.mg protein-1.5 s-1, respectively. Addition to the incubation medium of high concentrations of unlabeled biotin, its related compounds (biocytin, desthiobiotin, biotin methyl ester, thioctic acid, and thioctic amide), or substrates of known mitochondrial transporters (succinate, pyruvate, glutamate, malate, and phosphate) failed to cause any significant inhibition in uptake of [3H]biotin by mitochondria incubated in buffer pH 6.1 and 7.4. Furthermore, preloading mitochondria with unlabeled biotin, biocytin, malate, or aspartate failed to cause any significant stimulation in biotin uptake. At incubation buffer pH 6.1, treatment of mitochondria with the protonophore FCCP caused significant inhibition in pH-dependent overshoot of biotin uptake. However, treatment of mitochondria with the potassium ionophore valinomycin caused significant stimulation in the pH-dependent overshoot of biotin uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
31
Rendon, D. A. "Mitochondrial Bioenergetics after Nine-Day Treatment Regimen with Benzonidazole in Rats." International Journal of Toxicology 26, no. 6 (November 2007): 571–75. http://dx.doi.org/10.1080/10915810701728698.
Full textAbstract:
The bioenergetics of cardiac, liver, and kidney mitochondria after 9-day treatment regimen with benzonidazole was studied in rats. The drug was given by oral gavage to adult male Sprague-Dawley rats for 9 consecutive days (100 mg benzonidazole/kg body weight as daily dose). The assayed mitochondrial bioenergetic parameters were the state 4, state 3, respiratory control, efficiency of oxidative phosphorylation, and the activity of the mitochondrial ATP synthase. The results showed that mitochondrial parameters were not altered statistically after in cardiac and kidney mitochondria, but respiratory control in liver mitochondria was statistically increased with benzonidazole treatment. This change was likely due to a slight decrease in state 4 bioenergy metabolism. These results indicate that 9-day benzonidazole treatment regimen had no negative effect on cardiac, liver, and kidney mitochondrial energy metabolism but increased respiratory control in rat liver mitochondria.
32
McCormack, J. G. "Characterization of the effects of Ca2+ on the intramitochondrial Ca2+-sensitive enzymes from rat liver and within intact rat liver mitochondria." Biochemical Journal 231, no. 3 (November 1, 1985): 581–95. http://dx.doi.org/10.1042/bj2310581.
Full textAbstract:
The regulatory properties of the Ca2+-sensitive intramitochondrial enzymes (pyruvate dehydrogenase phosphate phosphatase, NAD+-isocitrate dehydrogenase and 2-oxoglutarate dehydrogenase) in extracts of rat liver mitochondria appeared to be essentially similar to those described previously for other mammalian tissues. In particular, the enzymes were activated severalfold by Ca2+, with half-maximal effects at about 1 microM-Ca2+ (K0.5 value). In intact rat liver mitochondria incubated in a KCl-based medium containing 2-oxoglutarate and malate, the amount of active, non-phosphorylated, pyruvate dehydrogenase could be increased severalfold by increasing extramitochondrial [Ca2+], provided that some degree of inhibition of pyruvate dehydrogenase kinase (e.g. by pyruvate) was achieved. The rates of 14CO2 production from 2-oxo-[1-14C]glutarate at non-saturating, but not at saturating, concentrations of 2-oxoglutarate by the liver mitochondria (incubated without ADP) were similarly enhanced by increasing extramitochondrial [Ca2+]. The rates and extents of NAD(P)H formation in the liver mitochondria induced by non-saturating concentrations of 2-oxoglutarate, glutamate, threo-DS-isocitrate or citrate were also increased in a similar manner by Ca2+ under several different incubation conditions, including an apparent ‘State 3.5’ respiration condition. Ca2+ had no effect on NAD(P)H formation induced by β-hydroxybutyrate or malate. In intact, fully coupled, rat liver mitochondria incubated with 10 mM-NaCl and 1 mM-MgCl2, the apparent K0.5 values for extramitochondrial Ca2+ were about 0.5 microM, and the effective concentrations were within the expected physiological range, 0.05-5 microM. In the absence of Na+, Mg2+ or both, the K0.5 values were about 400, 200 and 100 nM respectively. These effects of increasing extramitochondrial [Ca2+] were all inhibited by Ruthenium Red. When extramitochondrial [Ca2+] was increased above the effective ranges for the enzymes, a time-dependent deterioration of mitochondrial function and ATP content was observed. The implications of these results on the role of the Ca2+-transport system of the liver mitochondrial inner membrane are discussed.
33
Keshavarzi, Amir, Akram Ranjbar, Nejat Kheiripour, Ali Ghaleiha, Alireza Soltaniyan, and Seyyed Mostafa Hashemi. "Comparing the Effect of Grape Fermentative Product and Fresh Red Grape Juice on Antioxidant Biomarkers of Liver Mitochondria Isolated From Rats in Vitro." Research in Molecular Medicine 9, no. 1 (January 25, 2021): 21–28. http://dx.doi.org/10.32598/rmm.9.1.3.
Full textAbstract:
Background: Mitochondria are a source of reactive oxygen species (ROS), and several natural compounds are used as antioxidant agents. This study aimed to investigate and compare the effects of fresh grape juice red wine on oxidative stress biomarkers in rat liver mitochondria. Materials and Methods: In this regard, mitochondria were isolated from the liver of 27 male Wistar rats (220-250 g). The isolated mitochondria were cultured in different doses of red wine and fresh red grape juice for 24, 48, and 72 h. After treatment, total antioxidant capacity, lipid peroxidation, total thiol groups, and catalase activity were determined in the isolated mitochondria of the rat liver. Results: The results confirmed the oxidant/antioxidant effects of red wine and fresh red grape juice at different times. Conclusion: According to the results, the fresh red grape juice showed higher antioxidant properties than red wine in the liver mitochondrial samples.
34
Allred, J. B., and C. R. Roman-Lopez. "Enzymatically inactive forms of acetyl-CoA carboxylase in rat liver mitochondria." Biochemical Journal 251, no. 3 (May 1, 1988): 881–85. http://dx.doi.org/10.1042/bj2510881.
Full textAbstract:
Biotinyl proteins were labelled by incubation of SDS-denatured preparations of subcellular fractions of rat liver with [14C]methylavidin before polyacrylamide-gel electrophoresis. Fluorographic analysis showed that mitochondria contained two forms of acetyl-CoA carboxylase [acetyl-CoA:carbon dioxide ligase (ADP-forming) EC 6.4.1.2], both of which were precipitated by antibody to the enzyme. When both forms were considered, almost three-quarters of the total liver acetyl-CoA carboxylase was found in the mitochondrial fraction of liver from fed rats while only 3.5% was associated with the microsomal fraction. The remainder was present in cytosol, either as the intact active enzyme or as a degradation product. The actual specific activity of the cytosolic enzyme was approx. 2 units/mg of acetyl-CoA carboxylase protein while that of the mitochondrial enzyme was about 20-fold lower, indicating that mitochondrial acetyl-CoA carboxylase was relatively inactive. Fractionation of mitochondria with digitonin showed that acetyl-CoA carboxylase was associated with the outer mitochondrial membrane. The available evidence suggests that mitochondrial acetyl-CoA carboxylase represents a reservoir of enzyme which can be released and activated under lipogenic conditions.
35
RIGOBELLO, Maria Pia, Arianna DONELLA-DEANA, Luca CESARO, and Alberto BINDOLI. "Distribution of protein disulphide isomerase in rat liver mitochondria." Biochemical Journal 356, no. 2 (May 24, 2001): 567–70. http://dx.doi.org/10.1042/bj3560567.
Full textAbstract:
Here we report the localization of protein disulphide isomerase (PDI) in the mitochondrial compartments, comparing it with that of thioredoxin reductase. The latter enzyme is present mostly in the matrix, whereas PDI is located at the level of the outer membrane. We characterize the different submitochondrial fractions with specific marker enzymes. PDI, whether isolated from whole mitochondria or from purified outer membranes, exhibits the same electrophoretic mobility, indicating identical molecular masses. Moreover, immunoblot analysis with monoclonal anti-PDI antibody shows immunoreactivity only with the microsomal PDI, indicating the specificity of the mitochondrial isoform. The significance of these findings is discussed with reference to the potential role of PDI and thioredoxin reductase in regulating the mitochondrial functions dependent on the thiol–disulphide transition.
36
Cairns, Charles B., James Walther, Alden H. Harken, and Anirban Banerjee. "Mitochondrial oxidative phosphorylation thermodynamic efficiencies reflect physiological organ roles." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 274, no. 5 (May 1, 1998): R1376—R1383. http://dx.doi.org/10.1152/ajpregu.1998.274.5.r1376.
Full textAbstract:
Mitochondria cannot maximize energy production, efficiency, and the cellular ATP phosphorylation potential all at the same time. The theoretical and observed determinations of coupling of oxidative phosphorylation in mitochondria from rat liver, heart, and brain were compared using classical and nonequilibrium thermodynamic measures. Additionally, the optimal thermodynamic efficiency and flow ratios were determined for control of the two energy-converting complexes of the respiratory chain: complex I (NADH), which reflects the integrated cellular pathway, and complex II (FADH2), the predominantly tricarboxylic acid (TCA) cycle pathway. For all three organs, the cellular respiratory pathway was more tightly coupled than the TCA pathway and resulted in a greater optimal efficiency. Liver mitochondria are the most thermodynamically efficient at ATP production using oxidative phosphorylation. Heart and brain mitochondrial systems utilize more oxygen, but can produce ATP at a faster rate than liver systems. Per the theory of economic degrees of coupling, isolated rat liver mitochondrial systems are designed for the economic production of ATP for use in cellular processes. In the brain, the mitochondrial TCA cycle pathway promotes the maximal maintenance of the cellular energy state for cellular viability, whereas in the heart the TCA cycle pathway maximizes the production of ATP. The coupling of oxidative phosphorylation not only can be expected to change with substrate availability but may also reflect an ontogenetic response of mitochondria to fit specific organ roles in the rat.
37
Kawamoto, S., T. Sonoda, A. Ohtake, and M. Tatibana. "Stimulatory effect of arginine on acetylglutamate synthesis in isolated mitochondria of mouse and rat liver." Biochemical Journal 232, no. 2 (December 1, 1985): 329–34. http://dx.doi.org/10.1042/bj2320329.
Full textAbstract:
N-Acetyl-L-glutamate synthetase (EC 2.3.1.1) catalyses the synthesis of N-acetyl-L-glutamate, an allosteric activator of carbamoyl-phosphate synthetase I in the liver of ureotelic animals, and the first enzyme is activated specifically by arginine. We have proposed that arginine can stimulate acetylglutamine synthetase in vivo and thereby increase the mitochondrial content of acetylglutamate. The effects of arginine on acetylglutamate synthesis in isolated mitochondria were investigated in detail in the present work. When rat liver mitochondria were isolated and incubated with [14C]glutamate and unlabelled acetate as substrates, acetyl[14C]glutamate synthesis in the mitochondria was more extensive in the presence than in the absence of L-arginine. There was no significant difference between the specific radioactivities of intramitochondrial [14C]glutamate in the presence and absence of arginine. When rat liver mitochondria were incubated with [14C]acetate and unlabelled glutamate as substrates, arginine also stimulated acetyl[14C]glutamate synthesis in the isolated mitochondria. L-Lysine or L-homoarginine, which does not activate acetylglutamate synthetase, had no effect on acetylglutamate synthesis, in the isolated mitochondria. The arginine concentration giving half-maximal synthesis of acetylglutamate in isolated mitochondria was about 50 microM, which is in the range of physiological concentrations of arginine in the liver. As we previously reported [Kawamoto, Ishida, Mori & Tatibana (1982) Eur. J. Biochem. 123, 637-641], the sensitivity of acetylglutamate synthetase to arginine activation undergoes marked changes after food ingestion. The extent of arginine activation of acetylglutamate synthesis in isolated mitochondria correlated well with the sensitivity of acetylglutamate synthetase extracted from the mitochondria to arginine activation. These data lend further support to the idea that arginine itself activates the mitochondrial synthesis of acetylglutamate.
38
Justo, Roberto, Jordi Boada, Margalida Frontera, Jordi Oliver, Jordi Bermúdez, and Magdalena Gianotti. "Gender dimorphism in rat liver mitochondrial oxidative metabolism and biogenesis." American Journal of Physiology-Cell Physiology 289, no. 2 (August 2005): C372—C378. http://dx.doi.org/10.1152/ajpcell.00035.2005.
Full textAbstract:
In the present study, we have investigated gender differences in rat liver mitochondrial oxidative metabolism. Total mitochondrial population (M) as well as the heavy (M1), medium (M3), and light (M8) mitochondrial fractions obtained by means of differential centrifugation steps at 1,000, 3,000, and 8,000 g, respectively, were isolated. Electron microscopic analysis was performed and mitochondrial protein content and cardiolipin levels, mitochondrial O2 flux, ATP synthase activity, mitochondrial membrane potential, and mitochondrial transcription factor A (TFAM) protein levels were measured in each sample. Our results indicate that mitochondria from females have higher protein content and higher cardiolipin levels, greater respiratory and phosphorylative capacities, and more-energized mitochondria in respiratory state 3. Moreover, protein levels of TFAM were four times greater in females than in males. Gender differences in the aforementioned parameters were more patent in the isolated heavy M1 and M3 mitochondrial fractions. The present study demonstrates that gender-related differences in liver mitochondrial function are due mainly to a higher capacity and efficiency of substrate oxidation, likely related to greater mitochondrial machinery in females than in males, which is in accord with greater mitochondrial differentiation in females.
39
Mashayekhi, V., K. Haj Mohammad Ebrahim Tehrani, M. Hashemzaei, K. Tabrizian, J. Shahraki, and M.-J. Hosseini. "Mechanistic approach for the toxic effects of perfluorooctanoic acid on isolated rat liver and brain mitochondria." Human & Experimental Toxicology 34, no. 10 (January 13, 2015): 985–96. http://dx.doi.org/10.1177/0960327114565492.
Full textAbstract:
Background: Perfluorooctanoic acid (PFOA) is one of the most widely used perfluoroalkanes as surfactants, lubricants and processing aids in the production of polymers, which has also been detected in the environment, wildlife and human body. Animal studies indicated that PFOA caused a wide array of toxic effects including liver and brain dysfunction, carcinogenicity and reproductive and developmental toxicity. Based on the established role of mitochondria-mediated pathways in the observed toxic effects of many drugs and chemicals, in this study, the potential toxic effects of PFOA on mitochondria isolated from rat liver and brain have been investigated. Method: Mitochondria were isolated by differential centrifugation method and incubated with different concentrations of PFOA (0.5–1.5 mM). The effects of PFOA were assessed on a series of mitochondrial parameters including reactive oxygen species (ROS) formation, activities of mitochondrial complexes I/II/III, reduced glutathione (GSH) content, adenosine triphosphate (ATP) level, membrane potential, lipid peroxidation (LPO), mitochondrial swelling and cytochrome c release. Results: The data on liver mitochondria indicated that PFOA-induced ROS elevation in both mitochondrial complexes I and III, mitochondrial membrane potential collapse, swelling, cytochrome c release and decreased ATP level which induces apoptosis or necrosis. On brain mitochondria, PFOA showed fairly similar effects on the above-mentioned parameters. However, different results were obtained when the effect of PFOA was assessed on LPO and complex II activity. Conclusions: Due to the fact that PFOA had toxic effects on the mitochondria isolated, it could be suggested that mitochondrial toxicity could be a plausible mechanism for the toxic effects of this fluorochemical on liver and brain function.
40
Naučienė, Zita, Rasa Žūkienė, Laima Degutytė-Fomins, and Vida Mildažienė. "Mitochondrial Membrane Barrier Function as a Target of Hyperthermia." Medicina 48, no. 5 (June 5, 2012): 36. http://dx.doi.org/10.3390/medicina48050036.
Full textAbstract:
Background and Objective. Hyperthermia is a promising modality for cancer treatment that urgently requires detailed knowledge on molecular and cellular processes for the rational development of treatment protocols. The thorough study of the response of the inner membrane of heart and liver mitochondria to hyperthermia was performed in order to establish the pattern of the hyperthermia-induced changes in the membrane barrier function. Material and Methods. The isolated mitochondria from rat heart and liver (of both genders) were used for experiments, as well as mitochondria isolated from the perfused male rat liver. Changes in the membrane permeability were evaluated by mitochondrial respiration in state 2 or by estimation of the modular kinetics of the membrane leak. Results. The inner membrane of isolated mitochondria from healthy tissues was found to be an extremely sensitive target of hyperthermia that exerted the response even in the febrile range. More severe hyperthermia compromised the inner mitochondrial membrane function; however, this response was tissue-specific and, to some extent, gender-dependent (for liver mitochondria). The data obtained by direct heating of isolated mitochondria were validated by experiments on the perfused liver. Conclusions. The obtained results imply a crucial importance of the evaluation of the tissue- and gender-specific differences while developing or improving the protocols for hyperthermic treatment or combinatory therapy.
41
Hagen, Thilo, Christopher J. Lagace, Josephine S. Modica-Napolitano, and June R. Aprille. "Permeability transition in rat liver mitochondria is modulated by the ATP-Mg/Pi carrier." American Journal of Physiology-Gastrointestinal and Liver Physiology 285, no. 2 (August 2003): G274—G281. http://dx.doi.org/10.1152/ajpgi.00052.2003.
Full textAbstract:
Mitochondrial permeability transition, due to opening of the permeability transition pore (PTP), is triggered by Ca2+ in conjunction with an inducing agent such as phosphate. However, incubation of rat liver mitochondria in the presence of low micromolar concentrations of Ca2+ and millimolar concentrations of phosphate is known to also cause net efflux of matrix adenine nucleotides via the ATP-Mg/Pi carrier. This raises the possibility that adenine nucleotide depletion through this mechanism contributes to mitochondrial permeability transition. Results of this study show that phosphate-induced opening of the mitochondrial PTP is, at least in part, secondary to depletion of the intramitochondrial adenine nucleotide content via the ATP-Mg/Pi carrier. Delaying net adenine nucleotide efflux from mitochondria also delays the onset of phosphate-induced PTP opening. Moreover, mitochondria that are depleted of matrix adenine nucleotides via the ATP-Mg/Pi carrier show highly increased susceptibility to swelling induced by high Ca2+ concentration, atractyloside, and the prooxidant tert-butylhydroperoxide. Thus the ATPMg/Pi carrier, by regulating the matrix adenine nucleotide content, can modulate the sensitivity of rat liver mitochondria to undergo permeability transition. This has important implications for hepatocytes under cellular conditions in which the intramitochondrial adenine nucleotide pool size is depleted, such as in hypoxia or ischemia, or during reperfusion when the mitochondria are exposed to increased oxidative stress.
42
Vamecq, J., J. P. Draye, and J. Brison. "Rat liver metabolism of dicarboxylic acids." American Journal of Physiology-Gastrointestinal and Liver Physiology 256, no. 4 (April 1, 1989): G680—G688. http://dx.doi.org/10.1152/ajpgi.1989.256.4.g680.
Full textAbstract:
Recently, we demonstrated in rat liver that dicarboxylic acids containing more than five carbons can be activated by a microsomal dicarboxylyl-CoA synthetase (J. Vamecq, E. de Hoffmann, and F. Van Hoof. Biochem. J. 230: 683-693, 1985). The products of this reaction, dicarboxylyl-CoA esters, were found to be substrates for an H2O2-generating dicarboxylyl-CoA oxidase. In the present work we report that 1) the catalytic center or the essential domains of dicarboxylyl-CoA synthetase are located at the cytosolic aspect of the endoplasmic reticulum membrane; 2) dicarboxylyl-CoA oxidase is optimally active on dodecanedioyl-CoA and is a peroxisomal enzyme; 3) cyanide-insensitive dodecanedioyl-CoA oxidation (NADH production) is catalyzed by rat liver homogenates. Cell fractionation studies disclose that, similar to dodecanedioyl-CoA oxidase (H2O2 production), the cyanide-insensitive dodecanedioyl-CoA oxidizing activity also belongs to peroxisomes; 4) a dodecanedioyl-CoA oxidoreductase reaction can be assayed by the dichlorphenolindophenol procedure in rat liver homogenates, and the activity is abundant in peroxisomal, mitochondrial, and soluble fractions; 5) by contrast with monocarboxylyl-CoA esters, the dicarboxylyl-CoAs are apparently not substrates for mitochondrial fatty acid oxidation; however, the use of dicarboxylylcarnitine esters as direct substrate for mitochondria suggests the existence of an active beta-oxidation of dicarboxylates in these organelles, which is further confirmed by experiments in which mitochondria are permeabilized with digitonin; 6) the in vivo oxidation of infused dodecanedioic acid results in a rapid appearance in urine of medium-chain dicarboxylic acids, with only 30-50% of the infused dose recovered in urine.
43
Barreto, George Emílio Sampaio, Gleide Souza dos Santos, Eryvaldo Sócrates Tabosa Egito, and Ramon dos Santos El-Bachá. "Catechol inhibits FADH2-linked respiration in rat liver mitochondrial fraction." Acta Cirurgica Brasileira 20, suppl 1 (2005): 40–45. http://dx.doi.org/10.1590/s0102-86502005000700008.
Full textAbstract:
PURPOSE: The aim of this work was to investigate the hypothesis that catechol inhibits FADH2-linked basal respiration in mitochondria isolated from rat liver homogenates. Moreover, catechol ability to induce peroxidation of biomolecules in liver nuclear fractions was also studied. METHODS: Rat liver homogenates were incubated with 1mM 1,2-dihydroxybenzene (catechol) at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate. Nuclear fractions were incubated in the presence of 1 mM catechol for 17 hours at room temperature and the peroxidation of biomolecules was investigated by the reaction with thiobarbituric acid, which was determined spectrophotometrically at 535 nm. RESULTS: Catechol induced a time-dependent partial inhibition of FADH2-linked basal mitochondrial respiration, however this substance was unable to induce a direct peroxidation of biomolecules in hepatic nuclear fractions. CONCLUSION: Catechol produced an inhibition of basal respiration associated to FADH2 in isolated liver mitochondria that could lead to cytotoxicity, ROS generation and cell death.
44
Lund, Patricia, and David Wiggins. "Chelating agents and rat liver mitochondria." Biochimica et Biophysica Acta (BBA) - Bioenergetics 975, no. 3 (August 1989): 330–35. http://dx.doi.org/10.1016/s0005-2728(89)80340-8.
Full text
45
Porter, Richard K., John M. Scott, and Martin D. Brand. "Choline transport into rat liver mitochondria." Biochemical Society Transactions 20, no. 3 (August 1, 1992): 248S. http://dx.doi.org/10.1042/bst020248s.
Full text
46
Moraga-A, David A., Kathleen M. MacPhee-Quiggley, James F. Keefer, and Sheldon M. Schuster. "Asparagine catabolism in rat liver mitochondria." Archives of Biochemistry and Biophysics 268, no. 1 (January 1989): 314–26. http://dx.doi.org/10.1016/0003-9861(89)90593-6.
Full text
47
Vekshin, Nikolai, Vladimir Kovalev, and Alina Chaplygina. "Germinal proto-mitochondria from rat liver." Biochemistry and Biophysics Reports 20 (December 2019): 100710. http://dx.doi.org/10.1016/j.bbrep.2019.100710.
Full text
48
Tsai, C. Stan, and David J. Senior. "Chemical studies of high-Km aldehyde dehydrogenase from rat liver mitochondria." Biochemistry and Cell Biology 69, no. 2-3 (February 1, 1991): 193–97. http://dx.doi.org/10.1139/o91-028.
Full textAbstract:
Studies of pH-dependent kinetics implicate two ionizable groups in the dehydrogenase and esterase reactions catalysed by high-Km aldehyde dehydrogenase from rat liver mitochondria. Sensitized photooxidation completely arrests the bifunctional activities of the dehydrogenase. Carboxamidomethylation abolishes the dehydrogenase activity, whereas acetimidination eliminates the esterase activity. These results suggest that histidine (pKa near 6) and cysteine (pKa near 10) are likely the catalytic residues for the dehydrogenase activity, while the esterase activity is functionally related to histidine (pKa near 7) and a residue with the pKa value of 10–11. The two residues, a carboxyl group and an arginine, that discriminate between NAD+ and NADP+ are present at the coenzyme binding site of the mitochondrial high-Km aldehyde dehydrogenase from rat liver.Key words: aldehyde dehydrogenase, rat liver, mitochondria, esterase.
49
Knecht, E., A. Martinez-Ramón, and S. Grisolia. "Autophagy of mitochondria in rat liver assessed by immunogold procedures." Journal of Histochemistry & Cytochemistry 36, no. 11 (November 1988): 1433–40. http://dx.doi.org/10.1177/36.11.3171166.
Full textAbstract:
Glutamate dehydrogenase and carbamoyl phosphate synthase-I were localized in rat liver by immunogold procedures, using monoclonal and polyclonal antibodies. As expected, there was extensive labeling in mitochondria. Label was also found in lysosomal autophagic vacuoles. When autophagy was stimulated by in vivo administration of the anti-microtubular agent vinblastine we found that: (a) carbamoyl phosphate synthase-I and glutamate dehydrogenase could be found in mitochondria within autophagic vacuoles; (b) the carbamoyl phosphate synthase-I and glutamate dehydrogenase content of the mitochondria sequestered into autophagic vacuoles is the same as that of the nearby "free" mitochondria; and (c) in the whole liver, autophagic vacuoles contain c. 1.5 times more glutamate dehydrogenase than carbamoyl phosphate synthase-I, in contrast to mitochondria which have c. three times more carbamoyl phosphate synthase-I than glutamate dehydrogenase. The latter finding could explain, at least partially, the difference in half-lives of these enzymes.
50
Danpure, C. J., P. Purkiss, P. R. Jennings, and R. W. E. Watts. "Mitochondrial damage and the subcellular distribution of 2-oxoglutarate:glyoxylate carboligase in normal human and rat liver and in the liver of a patient with primary hyperoxaluria type I." Clinical Science 70, no. 5 (May 1, 1986): 417–25. http://dx.doi.org/10.1042/cs0700417.
Full textAbstract:
1. The subcellular distribution of 2-oxoglutarate:glyoxylate carboligase was investigated in a normal human liver, a liver from a patient with pyridoxine-resistant primary hyperoxaluria type I and rat livers subjected to various degrees and types of trauma. 2. On continuous sucrose gradients most of the carboligase fractionated with a peak equilibrium density of 1.19–1.20 g/cm3 and paralleled the distribution of the major peaks of monoamine oxidase, glutamate dehydrogenase and cytochrome oxidase and can be considered to be mitochondrial. Various proportions of the carboligase and mitochondrial marker enzymes were found to be ‘extramitochondrial’ (at or near the top of the sucrose gradients), depending on the liver source and the severity of trauma to which they were subjected. 3. Carboligase, monoamine oxidase (outer membrane marker) and glutamate dehydrogenase (matrix marker) were released from mitochondria by the homogenization and centrifugation procedures, to the extent of 19.9%, 32.4% and 11.5% respectively in hyperoxaluric liver, 12.5%, 17.9% and 8.2% in normal human liver and 3.0%, 4.9% and 3.8% in control rat liver. The proportion of extramitochondrial cytochrome oxidase (inner membrane marker) was virtually undetectable in both human and rat livers. However, sonication of rat liver homogenates or the addition of the detergent Triton X-100 caused a massive release of all four enzymes. 4. The extramitochondrial carboligase was probably in the form of a free protein of very high molecular weight or aggregate, rather than associated with a mitochondrion-derived organelle. 5. Subfractionation of a rat liver mitochondrial preparation indicated that most of the carboligase activity paralleled activities of 2-oxoglutarate decarboxylase, citrate synthase and glutamate dehydrogenase and was probably located in the matrix. The data were compatible with a previous suggestion that most of the carboligase is identical with the first decarboxylating component of the 2-oxoglutarate dehydrogenase complex. However, a significant minority of the carboligase activity showed a distribution different from that of 2-oxoglutarate decarboxylase, possibly due to structural alterations in the multi-enzyme complex. 6. We conclude that 2-oxoglutarate:glyoxylate carboligase is probably wholly mitochondrial and that the apparent cytosolic form of this enzyme is due to mitochondrial damage. Therefore previous suggestions that the lack of this component causes primary hyperoxaluria type I are no longer tenable.