Dissertations / Theses on the topic 'Metabolism nutrition'
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Robinson, Brenton Scott. "Choline nutrition and metabolism in sheep /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phr658.pdf.
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Trotter, James Marshall. "Nutrition and cancer : studies on nutritional abnormalities, nutritional support and protein metabolism in malnourished cancer patients /." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09MD/09mdt858.pdf.
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Coe, Benjamin Lloyd. "Obesity a growing concern about fetal nutrition /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4636.
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Thesis (M.A.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 6, 2007) Vita. Includes bibliographical references.
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Breen, Leigh. "Influence of protein nutrition and exercise on muscle metabolism." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1549/.
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At present, there is no clear consensus as to whether protein feeding harnesses any ergogenic benefit for endurance athletes. In this thesis demonstrate no effect of protein on endurance performance. Furthermore, data presented herein indicates that protein co-ingestion does not enhance recovery 24 hours after exercise. Consequently, there is currently no basis on which to recommend protein feeding for endurance performance and recovery. Nutrient strategies implemented after exercise can markedly alter the acute response of muscle protein synthesis and, potentially, long-term phenotypic adaptation. Protein nutrition has traditionally been considered in the context of resistance exercise. Endurance exercise followed by protein ingestion increases the synthesis of mixed muscle protein via increased mRNA translation. Herein, we demonstrate that protein feeding after endurance exercise elevates the synthetic rate of contractile proteins and specific mRNA signalling intermediates. Insulin resistance that precedes Type II diabetes is characterized by blunted sensitivity of the pancreas to glucose and impaired glucose uptake in skeletal muscle. Lifestyle interventions including nutrient and exercise have the potential to improve glycemic control. The final experimental chapter in this thesis provides mechanistic evidence to support the benefits of resistance exercise for lowering post-prandial glucose concentrations. Interestingly, protein ingestion did not augment the glucose-lowering effects of prior resistance exercise.
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Smith, Ruth Deborah. "Potassium intake, growth and energy metabolism." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295704.
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Hum, Susan. "Glutathione metabolism in the rat under varied nutritional conditions." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59940.
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We developed a methodology to measure plasma hepatic glutathione (GSH) turnover and we tested it in rats treated with an inhibitor of GSH synthesis. Our goal was to determine whether protein intakes above NRC recommendations maximize hepatic GSH stores and turnover in vivo. We also wished to learn if plasma GSH, cysteine, or methionine concentrations or plasma GSH turnover could be used as noninvasive predictors of liver GSH status. Rats were fed purified diets containing 0, 5, 10, 20 or 40% casein for one week. The 0 and 5% casein diets were considered inadequate in protein, 10% marginal, 20% adequate and 40% excessive. Liver GSH content (mmol/liver) of rats fed 0 and 5% casein diets was 12.29 $ pm$ 1.11 and 16.43 $ pm$ 0.95, respectively, and increased to 23.62 $ pm$ 1.82 in the 10% group. Liver GSH content did not differ between the 20 and 40% groups. As dietary casein increased from 0-20%, free plasma GSH and cysteine concentrations and plasma GSH turnover increased, but did not increase further with the 40% diet. A sigmoidal relationship between plasma GSH turnover and hepatic GSH content was demonstrated. The best predictor of liver GSH content was not free plasma GSH concentration nor plasma GSH turnover, but the free plasma cysteine concentration.
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Beggs, Louise Alice. "Evaluation of the problem solving method in nutrition education." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26164.
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The purpose of this study was to evaluate the problem solving method applied to a self-instructional material in nutrition education.
A comparative evaluation design was employed to determine the value of a problem solving model reflected in a commercially developed material, referred to as the 'Calcium Calculator'. Data were collected using a quasi-experimental randomized group pretest, posttest research design. A panel of judges then evaluated the impact of the problem solving method in nutrition education.
Three research questions were generated for the purpose of this study. The first involved comparing impacts produced by the two forms of the 'Calcium Calculator'. Measures of impact, selected based on learner objectives of the 'Calcium Calculator', were learners': attitudes toward dietary calcium and osteoporosis; perception of problem solving ability and self-reported dietary calcium intake.
The second research question was posed to investigate the nature of relationships between learners' levels of self-esteem and measures of instructional impact. Influences of selected biodemographic variables on change in the measures of impact were explored in the third research question.
Eighteen groups of women (n=241) from community centres were randomly assigned to one of three intervention groups: Groups A and B were exposed to active problem solving methods while group C viewed a film, a passive information-oriented instructional technique. The latter group was included in.the study since active learning was hypothesized to result in greater impact than passive learning. Pretest data were collected using a self-administered questionnaire and food intake form. Posttest data were collected an average of 4.7 weeks later using a modification of the pretest questionnaire which included a self-esteem scale, along with the food intake form. Forty-four percent of women (n=l06) who completed pretest questionnaires returned for the posttest session.
Participants in all three intervention groups experienced increases in attitude scores from pre- to posttest, and these changes were significant within groups B and C. Perceptions of problem solving ability were maintained within intervention groups B and C, yet decreased significantly within intervention group A. Significant increases in self-reported dietary calcium intakes occurred in all three intervention groups among non-pregnant women whose pretest dietary calcium intakes were below their Recommended Nutrient Intake.
Impacts produced by form A and B of the 'Calcium Calculator' were significantly different on only one dependent variable: perception of problem solving ability (p≤0.05). Changes in the dependent variables produced by problem solving versus non-problem solving interventions were not significantly different. Changes in dietary calcium intake and attitude toward dietary calcium and osteoporosis were not significantly correlated with self-esteem levels. However, positive significant correlations were identified between learners' levels of self-esteem and change in learners' perceptions of their problem solving ability (p≤0.0l).
Measures of impact were infrequently influenced by the biodemographic variables. Of the associations that were identified, most involved dietary characteristics of participants. Yet change in perception of problem solving ability was also affected by a combination of three demographic variables: age, employment status and education.
A panel of users (n=9) of educational materials was asked to make judgements on selected study results. Although judges did not distinguish between impacts produced by the two problem solving materials, they acknowledged that: (1) an important relationship exists between self-esteem and learners' perceptions of their problem solving ability and (2) the problem solving method is valuable when directed to specific kinds of learners.
The quasi-experimental research design used in this study appeared appropriate for the evaluation of innovative instructional methods. Two main advantages of the design were its comparative nature and its use of a panel of experts to judge the relative effectiveness of both forms of the 'Calcium Calculator' as well as the value of the problem solving method and self-esteem in material design.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
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Deng, Shuang. "Regulation of Ketone Body and Coenzyme A Metabolism in Liver." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1309875212.
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Lammes, Eva. "Nutrition, energy metabolism and body composition in the frail elderly /." Stockholm, 2007. http://diss.kib.ki.se/2006/91-7357-058-3/.
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Soop, Mattias. "Effects of perioperative nutrition on insulin action in postoperative metabolism /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-529-8/.
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Modie, J. A. "Nutrition and serotonin metabolism : studies in rat brain and platelets." Thesis, University of Surrey, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354766.
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Gardner, D. K. "The nutrition and energy metabolism of the preimplantation mouse embryo." Thesis, University of York, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380513.
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Katz, Roni. "Protein metabolism in septic patients ungergoing [sic] total parenteral nutrition /." Bern : [s.n.], 1989. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Reeves, Sue L. "Biological variation in basal metabolic rate and energy metabolism." Thesis, Oxford Brookes University, 1997. https://radar.brookes.ac.uk/radar/items/0950eae3-8373-4c20-8320-3aa491dcb325/1/.
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Biological variation is evident in all aspects of nutrition, particularly total daily energy expenditure (TDEE) and basal metabolic rate (BMR). The impact of ethnicity on biological variation on certain aspects of energy metabolism has been investigated. Predictive equations to estimate BMR were published by the FAOIWHOIUNU (1985) in a report entitled EllerK}' and Protein Requirements. Since its publication, serious concern has been expressed on the validity of these equations, largely because the analysis appears to be based on a biased and incomplete analysis of the world literature on BMR. Using an expanded database (n=10,004) and stringent selection criteria the global BMR data has been re-analysed and new predictive equations presented. The robustness of the new equations were tested by comparing their predictive accuracy with those of existing ones. The BMR of 77 women aged 18-30 years were found to be best described by the newly developed Oxford Brookes equations and the Henry & Rees (1991) equations for tropical peoples (P < 0.05 and NS respectively). Furthermore, the new expanded data base was used to plot nonnal curves for BMR for individuals which compared ethnic differences. It was observed that when BMR is expressed per kilogram of body mass, ethnic differences are diminished. The necessity to estimate TDEE in various ethnic groups prompted the evaluation of a non-invasive easy to use technique. Heart rate monitoring as a means of estimating TDEE is reviewed and compares favourably to the use of activity diaries. Whilst highly variable, heart rate monitoring is acknowledged as a valuable tool in the estimation of energy expenditure and activity in individuals and populations Ethnic differences in energy intake in a migrating student population were assessed. Malaysian students recently arrived in the UK were requested to keep food diaries in order to detect changes in their diets. Particular emphasis was placed on changes in the energy densities of food consumed and their effect on body weight and energy balance. After 6 months, it was observed that energy balance was maintained despite the energy density of food consumed in the UK being significantly (P < 0.05) more energy dense than food consumed in their native Malaysia. This illustrates the precise way in which the human body can maintain energy balance. Anthropometric differences were compared in 553 individuals from 4 ethnic groups in a study investigating the ann-span and height relationship. Differences were found between the ethnic groups (P < O.OI). The use of ann-span as a proxy for height should be used with caution. It is imperative that more global data collected under strict control is required before human biological variation can be attributed to true ethnic differences and not merely individual variation.
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Joung, Hyojee. "Changes in copper and zinc metabolism after trauma." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382028154.
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Thakkar, Sagar. "PRE-ABSORPTIVE METABOLISM OF CAROTENOIDS." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244048450.
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Cotten, Bradley Matthew. "Structural Modification of the Flavanone Naringenin – Potential Impacts in Dietary Polyphenol Research." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1525275809703267.
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Ip, P. M., and 葉沛汶. "Perinatal nutrition affects adiposity and skeletal muscle fat metabolism in rats." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30253111.
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Olenick, Alyssa. "Metabolic Flexibility Among Women after a Single High Fat Meal." TopSCHOLAR®, 2017. http://digitalcommons.wku.edu/theses/1970.
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PURPOSE: Obese women have increased rates of metabolic diseases compared to those of healthy weight status. Additionally, African-American (AA) women have higher rates of metabolic disease compared to Caucasian (CA) women. Metabolic inflexibility is the inability to adjust substrate oxidation in response to dietary intake; potentially leading to weight gain and the development of metabolic disease. Few studies have investigated the impact of weight status and/or ethnicity on the metabolic response of women to a single high fat meal. An acute unfavorable metabolic response may contribute to the higher incidence of metabolic disease among not only obese, but also AA women. Therefore, the purpose of this study was to determine the impact that weight status (lean vs. overweight/obese) and/or ethnicity (CA vs. AA) has on metabolic health in women in response to a single high fat meal. METHODS: CA (n= 15; age=26.27±5.65 yrs; BMI=30.72±11.92kg/m2) and AA (n= 12; age=26.75±6.65yrs; BMI=28.32±6.91kg/m2) women consumed a high fat shake (1062 calories, 56% fat). Blood was drawn and resting energy expenditure (REE) and substrate oxidation (estimated using indirect calorimetry) were assessed at baseline/fasted (T1), 120 minutes post-shake, (T2) 240 minutes post-shake (T3). RESULTS: Lipid and carbohydrate oxidation significantly increased among all women in response to the high fat meal (p<0.01). Significant increases in fat oxidation were seen from T1-T2 for all women (CA lean: +57.9±24.5%; CA overweight/obese: +30.2±11.8%; AA lean: +10.2±18.1%; AA overweight/obese: +40.6±52.6%; p<0.01). Among the CA women only, CA lean women displayed a significantly higher increase in fat oxidation in response to the meal compared to CA overweight/obese women, but there were no differences among lean and overweight/obese AA women. Similarly, weight status influenced changes in apolipoproteins after consuming the high fat meal among CA women, but not AA women. CONCLUSIONS: CA lean women displayed the most metabolic flexibility in response to the high fat meal. A metabolic system that is less able to respond to metabolic stimuli such as a high fat diet (as noted in all groups compared to lean CA women) may play a role in the increased metabolic disease prevalence among obese and AA women.
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Maitland, Smith Kevin Charles. "Tryptophan metabolism during reproduction in the rat." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243546.
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Harris, Sarah Elizabeth. "Experimental and clinical investigation into mammalian oocyte metabolism, nutrition and fertility." Thesis, University of Leeds, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250927.
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Martin, Karen Lesley. "Nutrition and energy metabolism of the mouse and human preimplantation embryo." Thesis, University of York, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333711.
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Willcox, Karen Kay. "EFFECTS OF AGING AND NUTRITION ON PLASMA LIPOPROTEINS IN NONHUMAN PRIMATES." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275320.
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Unsworth, Nancy Walters. "The Physiology and Molecular Biology of Iron Nutrition for Cyanobacteria." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/4529.
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In addition to nitrogen and phosphorus, iron is an essential nutrient for oceanic primary productivity. Unlike nitrogen and phosphorus however, negligible amounts of iron are supplied to surface waters through recycling or mixing but instead from the limited and sporadic input of aeolian particulate. The low concentration of iron that becomes biologically available from the dust places a serious constraint on the heavily iron-dependent processes of photosynthesis and nitrate reduction which affect primary productivity. As much as 47% of the total oceanic primary productivity can be attributed to cyanobacteria making them critical organisms in the biogeochemical cycles. This thesis addresses the effect of iron on primary productivity using a combined approach of physiological and molecular biology. The physiological response of three marine strains of Synechococcus to growth on different concentrations of FeEDTA was investigated. Cells grown with higher concentrations of iron had greater cell density, more Chl- and phycobiliproteins and higher carbon fixation rates than cells grown at limiting iron concentrations (l0-8 M Fe). Iron enrichment of iron limited cultures stimulated carbon fixation, growth rate, and pigment and protein synthesis. Iron limited cells spiked with SJ.l.M Nlf4Cl prior to short term incubations had higher dark carbon fixation than cells gro·wn at higher iron and also spiked to 5J.1M Nlf4Cl. The addition of ammonium relieves a restricted nitrogen assimilatory pathway in the low iron cells that is evidenced by increased dark carbon fixation. We propose that this measurement of enhanced dark carbon fixation could be a useful assay in supporting the contention that populations of Synechococcus in nitrate rich waters are iron limited. Molecular genetic techniques were used to look for the presence of an iron uptake gene in cyanobacteria. Preliminary results indicate that there is a gene that is homologous to the ferric uptake regulation (fur) gene in E. coli. This hybridization occurred in siderophore-producing cyanobacteria, but not in marine cyanobacteria that do not produce siderophores. The fact that marine Synechococcus do not produce siderophores and did not hybridize to the fur gene suggest that fundamentally different mechanisms for iron uptake operate in high biomass freshwater cyanobacteria and cyanobacteria from dilute oligotrophic waters.
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Albuquerque, Fernanda Michelazzo Cavalcanti de. "Avaliação do consumo alimentar e do estado nutricional em relação ao Zinco de pré-escolares submetidos a um programa de fortificação com ferro." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-06072017-160055/.
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Com o objetivo de verificar o consumo alimentar e o estado nutricional em relação ao zinco de crianças submetidas a um programa de suplementação com ferro, foram estudadas 150 crianças com idade entre 2 e 7 anos, que pertenciam a por 2 creches do município de São Paulo. O período de estudo foi de 7 meses, dividido em três fases (F0, F1 e F2); onde avaliou-se em cada fase a dieta oferecida e a concentração de zinco no eritrócito das crianças. Na fase inicial do estudo (F0) avaliou-se a dieta normal oferecidas nas creches e o estado nutricional inicial das crianças; na F1, a creche ST recebeu o alimento fortificado com ferro e a creche SM recebeu o mesmo alimento porém sem a fortificação. Já na F2, a creche ST recebeu o alimento sem fortificação e a SM o alimento fortificado. Pelos resultados obtidos pode-se concluir que: as dietas se apresentaram deficientes em caloria e zinco para a creche ST e também em ferro para a creche SM, não estando adequada especialmente para as crianças acima de 4 anos; a fortificação do queijo \"petit suisse\" com ferro aminoquelato não causou mudança na concentração de zinco nos eritrócitos das crianças analisadas ao longo do estudo, embora o estado nutricional das mesmas em relação a este mineral encontrava-se deficiente podendo ser atribuido à qualidade da dieta.Aiming to value the food consumption and the nutritional status of zinc on infants submitted to an iron supplementation program, were studied 150 pre-schollars aged 2 to 7 years old of two nurseries (ST e SM) in the city of São Paulo. Studies were seven month, based on three stages (F0, F1 e F2), where was assessed the diets offered and the erythrocite zinc on infants, in the each stage. In the initial stage (F0), were assessed the regular diets offered by the nurseries and the initial nutritional status on infants; in the F1), the diets from nursery ST had meals supplemented with iron and the diets from nursery SM had the same meals although without the supplementation. In F2), the diets from nursery ST had meals without the supplementation and the diets from nursery SM the meals supplemented with iron. According with the results we can conclude: the diets were calories and zinc deficient to nursery ST and iron defícient to nursery SM, also; the iron supplementation in the \"petit suisse\" cheese with aminoquell iron did not cause any change in the erythrocite zinc concentration of the children being studied although the nutritional status were zinc deficient due to a quality of the diets.
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Sonko, Bakary Jallow. "Studies of carbohydrate and fat oxidation in human energy metabolism." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240088.
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Snyder, Brian S. "Carbohydrate ingestion and mouth rinsing on metabolism and endurance exercise performance." Diss., Kansas State University, 2011. http://hdl.handle.net/2097/11993.
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Doctor of PhilosophyDepartment of Human Nutrition
Mark D. Haub
Maximizing performance and results in competitive events is something that all athletes strive to achieve. Nutritional strategies have been developed to best optimize the likelihood of success in competitive events. While dietary protein was classically believed to be the key macronutrient in exercise performance, overwhelming evidence now supports the role of maximizing carbohydrate intake and availability in endurance performance. The role of carbohydrate intake prior to, during and after endurance exercise has been heavily studied and relevant literature will be discussed herein. This paper consists of three chapters and a summary related to carbohydrate intake and performance outcomes in endurance sports. While nutritional status surrounding the endurance events is discussed, this paper focuses on the ergogenic and metabolic effects of carbohydrates during the endurance bout. Chapter one serves as a literature review of carbohydrate administration during endurance exercise. Types of carbohydrates, their role as substrates in liver and skeletal muscle during exercise, and their effects on endurance performance are discussed. The role of carbohydrate on central factors of fatigue and motor output also are covered. Chapter two addresses the role of multiple carbohydrate supplements on cycling performance. The role of these supplements on blood glucose, insulin, lactate, and IGFBP-1 also are discussed. Chapter three addresses the effect of nutritional status prior to exercise on the ability of a carbohydrate mouth rinse to impart a performance enhancing effect. There were no treatment effects (p>0.05) of the type carbohydrate ingested, compared with placebo, on selected metabolic and performance outcomes. Likewise, there was no ergogenic effect of mouth rinsing, in the fasted or fed state, in moderately trained endurance cyclists.
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Balonan, Lino C. "Long-term endocrine and metabolic changes associated with early nutrition in sprague-dawley rats." Thesis, Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19657948.
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Sawaya, A. L. "Aspects of energy metabolism in protein malnourished rats." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372913.
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Oakley, Francesca Rachel. "The influence on dietary fat on plasma lipoprotein metabolism and haemostatic variables." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314045.
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Ayer, Carol Theresa. "Methionine Metabolism in Fasciola Hepatica." PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/3954.
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5'-Deoxy-5'-methylthioadenosine (MTA) is derived from s-adenosylmethionine (AdoMet) during the synthesis of the polyamines spermidine and spermine. Methionine can be regenerated from MTA by one of two mechanisms. In mammalian cells and some microorganisms, MTA is degraded to adenine and 5-methylthioribose-1-phosphate (MTR-1-P) via MTA phosphorylase. In certain other microbes, however, MTA is catabolized in two steps; first to adenine and 5-methylthioribose (MTR) via MTA nucleosidase followed by conversion of MTR to MTR-1-P via MTR kinase.
This study was to demonstrate the presence of MTA nucleosidase or MTA phosphorylase in both redia containing cercariae and adult Fasciola hepatica Linnaeus, 1758. If MTA nucleosidase was present, it was wanted to determine if MTR kinase was also present.
The phosphate-dependent cleaving activity of MTA phosphorylase was demonstrated in the cell-free extracts of adult Fasciola hepatica along with an unidentified MTR metabolizing activity. Redia containing cercariae showed MTA nucleosidase and MTR kinase activity.
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Muthaukrishnan, L. "Effect of site of infection on host plant growth and metabolism." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379917.
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Vassilyadi, Photios. "Glutathione metabolism in a piglet model of colitis and protein malnutrition." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119470.
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Glutathione (γ-glutamyl-cysteinylglycine; GSH) is the most abundant low molecular weight thiol synthesized endogenously by all cells from glutamate, cysteine and glycine. Inflammatory bowel disease (IBD) is a debilitating condition associated with oxidative stress and protein energy malnutrition (PEM) (especially among children). The aim of this study was to investigate how nutrition and intestinal inflammation impact the regulation of GSH in red blood cells and tissues in a piglet model of dextran sodium sulfate (DSS)-induced colitis. This is the first study to combine the use of a stable isotope methodology to determine GSH synthesis and tandem mass spectrometry to analyze the concentration of GSH and its metabolites in various malnourished models of pediatric colitis. Our results demonstrated that GSH was uniquely regulated in tissues of healthy piglets, with the liver producing the most GSH. GSH concentration was ~20% lower in distal colon of well-nourished piglets with colitis and further reduced by ~60% in piglets with moderate PEM compared to healthy, well-nourished controls. Severe, but not moderate, protein deficiency altered GSH regulation on a systemic level, affecting metabolism in liver and compromising GSH concentration in red blood cells, ileal mucosa and spiral colon. No effect on GSH regulation was reported in moderately protein deficient piglets receiving a difference in protein quality or in moderately PEM piglets receiving probiotic supplementation or glucagon-like peptide 2, an anabolic hormone. In conclusion, we have demonstrated that protein malnutrition, a common consequence of IBD, exacerbates the deleterious effects of severe inflammation by affecting the regulation of GSH. Adequate protein consumption may play a more beneficial role than increasing macronutrient intake with respect to glutathione regulation during inflammation. This emphasizes the role of nutritional intervention, specifically increasing cysteine requirement, as a therapeutic approach towards rehabilitating patients with IBD.Le glutathion est l'un des principaux antioxydants de l'organisme. Il est produit de façon endogène à partir de glutamate, de cystéine et de glycine. La maladie inflammatoire de l'intestin est une condition débilitante associée au stress oxydatif et à la malnutrition protéique et énergétique (MPE), surtout chez les enfants. La présente étude avait pour but d'examiner l'effet de la nutrition et de l'inflammation intestinale sur l'état du glutathion dans les érythrocytes et les tissus en utilisant un modèle de colite induit par dextrane sulfate de sodium (DSS) chez des porcelets. Cette étude est la première à combiner l'utilisation d'isotopes stables pour déterminer la synthèse du glutathion et la spectrométrie de masse pour analyser la concentration du glutathion et de ses métabolites dans divers modèles de malnutrition et de colite pédiatrique. Nos résultats ont démontré que glutathion est uniquement régulé dans les tissus des porcelets sains, la majorité du glutathion étant produit dans le foie. La concentration de glutathion était inférieure d'environ 20% dans le côlon distal de porcelets bien nourris souffrant de colite par rapport aux porcelets sains et inférieure d'environ 60% chez les porcelets avec MPE par rapport aux porcelets bien nourris. Seulement un déficit sévère en protéines a compromis le métabolisme du foie et la concentration de glutathion dans les érythrocytes, la muqueuse iléale et le côlon spiralé. Aucun effet sur la régulation du glutathion n'a été démontré chez les porcelets recevant des protéines de différentes qualités, chez des porcelets avec MPE recevant une supplémentation probiotique ou une hormone anabolisante. En conclusion, nous avons démontré que la malnutrition protéique, une conséquence fréquente de l'inflammation intestinale, exacerbe les effets délétères de l'inflammation sévère en affectant la régulation du glutathion. La consommation adéquate de protéines peut jouer un rôle plus bénéfique que l'augmentation des macronutriments sur la régulation du glutathion. Ceci souligne le rôle de l'intervention nutritionnelle, spécifiquement l'augmentation de la cystéine, comme une approche thérapeutique à la réhabilitation des patients avec la maladie inflammatoire de l'intestin.
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Watt, Matthew J., and mikewood@deakin edu au. "Adrenergic regulation of carbohydrate metabolism during exercise." Deakin University. School of Health Sciences, 2001. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20051202.092251.
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1. This series of studies was undertaken to examine the adrenergic regulation of carbohydrate metabolism during exercise. Recreationally active males were tested during moderate to intense exercise on a stationary cycle ergometer. Venous and arterial plasma obtained from indwelling catheters was analysed for hormonal and metabolite responses, and hepatic glucose production and glucose uptake were measured using the tracer-dilution method with stable isotopes. Muscle samples were obtained by the needle biopsy technique to examine muscle glycogen utilisation and the flux of related muscle metabolites using enzymatic, fluorometric and radioisotopic techniques.
2. During moderate exercise adrenaline infusion induced a marked hyperglycemia and this was due to reduced glucose uptake rather than enhanced hepatic glucose production. The reduction in glucose uptake was most likely mediated by a decrease in glucose phosphorylation, as indicated by the accumulation of glucose 6-phosphate with adrenaline infusion.
3. The hyperglycemic response to intense exercise was prevented by the administration of α- and β-adrenergic antagonists. Adrenergic blockade was without effect on hepatic glucose production whereas glucose uptake was enhanced when compared with control subjects. These data support the notion that adrenergic mechanisms are more important in restraining glucose uptake than enhancing hepatic glucose production during intense exercise. Other glucoregulatory factors are responsible for the increase in glucose production during intense exercise.
4. Elevated plasma adrenaline levels during moderate exercise in untrained men increases skeletal muscle glycogen breakdown and PDH activation which results
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Intriago, Pablo. "Fatty acid metabolism in a flexibacterium and its role in crustacean nutrition." Thesis, Bangor University, 1990. https://research.bangor.ac.uk/portal/en/theses/fatty-acid-metabolism-in-a-flexibacterium-and-its-role-in-crustacean-nutrition(11232774-8084-428b-854b-8652696a0f43).html.
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The total fatty acid content of an estuarine Flexibacter trip and the relative proportion of the constituent fatty acids were affected by growth temperature, aeration and salinity. The proportion of Cl6:lw5 the main fatty acid, did not change with temperature, but was produced in higher concentrations in xhe aiMOu*t o{ shaking cultures. In contrast, the amount of both linoleic and linolenic acids varied with temperature and aeration. The concentration of Cl6:lw5 per mg of protein changed with temperature, whereas the concentrations of both polyunsaturates were relatively constant. Both the proportion and concentration of the polyunsaturates were markedly stimulated by increases in salinity, although total fatty acid per mg protein decreased with it. The highest concentration of fatty acid per mg of protein did not coincide with the highest percentage of polyunsaturated fatty acids (PUFAs), when Inp was grown in different carbon sources. Inp growing in glucose had the highest concentration of PUFAs per mg of protein. Radio labelled acetate and palmitate were differentially incorporated into the fatty acids of Inp2 a variant of Inp. Addition of cAMP inhibited the incorporation of radioactive precursors into PUFAs. In contrast the antibiotic cerulenin inhibited the incorporation of radio labelled substrate acetate and variant into C16:1. This strongly suggests that lnp2 posseses both the anaerobic and aerobic pathway for UFAs synthesis. Whilst PUFAs were absent when another variant lnp3 was grown in media with an osmotic strength close to that of seawater, PUFAs were produced when Inp3 was grown in a high osmotic strength medium. Addition of cAMP to the high osmotic strength medium prevented PUFAs synthesis. Artemia salina was grown to adulthood on diets consisting of bacteria, bacteria plus algae and algae only. Generally, there were no differences in survival between the diets. However, different diets reflected differences in the total dry weight. Addition of algae to the Inp3 diet increased PUFAs concentration per animal dry weight. It is suggested that Inp3 may be able to provide both PUFAs and exoenzymes, which assist in the digestion of algae.
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Townsend, R. "The influence of diet and nutrition on bone metabolism in endurance athletes." Thesis, Nottingham Trent University, 2016. http://irep.ntu.ac.uk/id/eprint/31215/.
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Both accelerated and suppressed bone remodelling can lead to the development of a stress fracture injury. A stress fracture injury can threaten an athlete’s performance by causing months of missed training time if a stress fracture is sustained during a crucial phase of the season. This thesis presents a series of studies that investigated bone metabolism in endurance athletes and potential ways to improve bone health and reduce the risk of stress fracture injury. Triathletes are endurance athletes that anecdotally have a high incidence of stress fracture injury, but there is limited research into bone health in these athletes. Therefore, the first two studies in this thesis investigated bone metabolism in a group of elite British triathletes during off-season and pre-competition training. The results showed that elite triathletes had elevated bone turnover at both phases of the season, although this was highest during off-season training. The high bone turnover may be related to large training volumes, low energy intakes and high dermal calcium losses in the sweat. Given the potential contribution of high dermal calcium losses to the disruption of calcium homeostasis and the different rates of losses in different types of training sessions, the timing of calcium ingestion around training sessions may be more important than total calcium intakes throughout the day. As such, the third study in this thesis investigated the mechanism and timeframe of Parathyroid hormone (PTH) and calcium regulation during exercise and recovery. The results showed that PTH secretion was controlled by a combination of changes in ionised calcium (Ca2+) and phosphate (PO4) and that the mechanism might be different during exercise and recovery. Taken together these results advocate the use of pre-exercise calcium supplementation, which may prevent the disruption of calcium homeostasis and attenuate the PTH and bone resorption response to intense exercise, although further research is required before this can be implemented in elite triathletes. The large training volumes performed by elite triathletes, meant that daily energy expenditures and energy requirements were high, although consuming almost 6,000 kcal.d-1 was difficult when three or four training sessions were regularly performed each day. Therefore, a practical nutritional intervention was needed to help triathletes ingest some of the required nutrients. The fourth study in this thesis investigated the effect of a post-exercise carbohydrate and protein (CHO+PRO) recovery solution on the bone metabolism response to an intense running bout. The results showed that consuming a CHO+PRO recovery solution immediately after exercise created a more positive bone turnover balance in the acute recovery period from exercise, by suppressing bone resorption and increasing bone formation. Further research is required to explore the long-term effects of post-exercise suppression of bone resorption. This thesis had direct impact on elite British triathletes, by influencing athlete behaviour and nutritional practices in the daily training environment. The research has also influenced British Triathlon coaches and sports science and medicine staff by increasing the importance placed on bone health and by providing information that will allow training and nutritional practices to be improved or altered to promote a more anabolic environment for bone.
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Jackson, Alicia R. "Transport and Metabolism of Glucose in Intervertebral Disc." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/479.
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Low back pain is a major social and economic dilemma in the United States. Despite its high impact, the origins of low back remain unclear. Nonetheless, degenerative changes to the intervertebral discs (IVD) of the spine have been implicated as a possible source leading to pain. Poor nutritional supply to the IVD is believed to play a primary role in the pathophysiology of disc degeneration. Since the disc is avascular, vital nutrients, such as glucose, must be supplied by surrounding blood vessels. However, the transport and metabolic properties of glucose in the IVD have not been fully delineated. This knowledge is necessary in order to elucidate the nutrition-related mechanisms of disc degeneration. Therefore, in this dissertation, experimental and theoretical methods are used to investigate the transport and metabolism of glucose in the intervertebral disc. Strain-dependent and anisotropic (i.e., direction-dependent) transport of glucose in human annulus fibrosus (AF) was investigated using custom apparatuses. Results indicate that diffusivity and partitioning of glucose in human AF decreases with increasing compressive strain. Furthermore, diffusivity of glucose is anisotropic, being lower in the radial direction than the axial or circumferential directions at all strain levels. Transport of glucose in human AF was also found to diminish with increasing disc degeneration. A new method was developed to measure the rate of glucose consumption by IVD cells; this method was then validated with porcine AF and nucleus pulposus (NP) cells at varying levels of oxygen tension. Results show a positive Pasteur effect, with the glucose consumption rate by AF and NP cells increasing at low levels of oxygen. Moreover, results indicate that the rate of consumption of glucose by NP cells is significantly higher than that by AF cells. A new, three-dimensional finite element model of the IVD was developed in order to theoretically predict nutrient distributions in the disc. This model incorporated anatomical disc geometry, nutrient transport coupled to cellular metabolism, and mechanical loading conditions. The model was used to investigate the effects of endplate calcification and in vivo loading conditions on glucose distributions in the disc. Both calcification and compressive loading resulted in diminished glucose concentrations in the tissue. The model was also used to analyze the effects of degeneration and compression on cell viability in IVD by incorporating viability criteria. Our model could predict cell death in degenerated tissue, and compressive loading augmented this effect. The model prediction can be used to supplement experimental results, and may also serve as a useful tool in developing new strategies for the treatment of disc degeneration. The findings of this dissertation greatly enhance the knowledge of glucose transport and metabolism in the intervertebral disc. Given that glucose is a critical nutrient for disc cell survival, this knowledge can provide important insight into nutritional pathways and mechanisms in the IVD, as well as related disc degeneration.
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Wilson, Kirkland A. Wilson. "Interrelations Between 3-Hydroxypropionate, Propionate, And ß-Alanine Metabolism: Relevance To Propionic Acidemia." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1515518969675728.
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Cambron, Liz Doralyn. "Factors Affecting Metabolism During Non-Feeding Stages in Insects." Diss., North Dakota State University, 2020. https://hdl.handle.net/10365/31868.
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Although feeding is important for optimal development and growth in insects, there are several points during the insect life cycle that are non-feeding: metamorphosis, pupation, and overwintering. Non-feeding periods also occur in response to internal cues, such as feedback from nutrient thresholds and immune responses being activated. Additionally, as an insect goes through different developmental stages, its nutritional requirements change in response to or in preparation for non-feeding periods. Most physiological responses like feeding are regulated through an interconnection of pathways, but how these networks change in response to different energy demands, such as immune challenges or changes in metabolism, is poorly understood. One significant pathway that is involved in regulating several physiological processes is the insulin signaling pathway. In my dissertation research, I tested hypotheses explaining the regulation of physiological processes during non-feeding periods in two agriculturally relevant insects, Manduca sexta and Megachile rotundata. First, I investigated how internal cues such as dietary lipid content and immune challenges cause non-feeding periods in M. sexta. Then, I investigated how insulin signaling regulates development during a non-feeding period like overwintering changes in M. rotundata. Since the insulin signaling (IIS) pathway is critical for development and growth, I focused on testing if this pathway plays a role in regulating non-feeding periods. My research showed that increased dietary lipid content causes a cessation of feeding, which suggests there is a possible lipid threshold that when reached, causes M. sexta to switch from lipid consumption for storage to lipid excretion. When looking at another cue like immune challenges, my results showed that during a bacterial infection, a Toll-mediated suppression of IIS pathway may be regulating feeding and causing a non-feeding period exhibited as sickness-induced anorexia. Lastly, my results also showed that the IIS pathway is suppressed in overwintering M. rotundata, and that this process can change in response to temperature. Overall, my dissertation research showed that the insulin signaling pathway and nutrient content play a vital role in regulating non-feeding periods. Investigating insulin signaling, lipid metabolism, and innate immunity in these species closes a gap in knowledge of invertebrate development.
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Shen, Qian. "Histoplasma circumvents nutrition limitations to proliferate within macrophages." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563371073816792.
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Miguel, Juliana Samila de Castro. "Efeito de microminerais orgânicos no crescimento e qualidade do filé de tilápia (Oreochromis niloticus)." Dracena, 2020. http://hdl.handle.net/11449/192384.
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Orientador: Leonardo Susumu TakahashiResumo: Os microminerais possuem papéis importantes no metabolismo animal, participam de funções fisiológicas, crescimento, desenvolvimento e saúde em peixes. O objetivo deste estudo foi avaliar a suplementação da dieta com microminerais orgânicos no desempenho produtivo e qualidade do filé de juvenis de tilápia (Oreochromis niloticus). Foram formuladas 3 dietas práticas isoprotéicas e isoenergéticas com três níveis de inclusão (0,0; 1,0 e 1,5%) de um blend de microminerais orgânicos composto por: ferro, zinco, manganês, cobre, selênio e cromo. Foram realizados dois experimentos distintos, um com alimentação durante período pré-abate (7 dias) e outro, durante período longo de alimentação (30 dias). Em cada um dos experimentos, foram utilizados 120 juvenis em fase de terminação com peso médio de 360,6 g, distribuídos aleatoriamente em 12 caixas de 1000 L em um sistema de circulação fechado. Foram avaliados parâmetros da qualidade do filé no período pré-abate (7 dias): potencial hidrogeniônico (pH), rendimento de filé, cor, perdas de peso cozimento (cooking loss), perdas de peso por descongelamento (drip loss) e capacidade de retenção de água (CRA). As análises no após período de 30 dias de alimentação, foram as mesmas do período pré-abate com adição de: parâmetros de desempenho produtivo (ganho de peso, conversão alimentar e taxa de crescimento específico), textura do filé, oxidação lipídica (TBARS), concentração de bases voláteis totais (BVT), concentração de nitrogênio não protéico ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Microminerals play important roles in animal metabolism participate in physiological functions, growth, development and health in fish. The aim of this study was to evaluate the dietary supplementation with organic microminerals in the productive performance and quality of the tilapia (Oreochromis niloticus) juvenile fillet. A 120 juveniles were used in the finishing phase with an average weight of 360.6 g, randomly distributed in 12 boxes of 1000 L in a closed circulation system. 3 practical isoproteic and isoenergetic diets were formulated with three levels of inclusion (0.0, 1.0 and 1.5%) of a blend of organic minerals composed of: iron, zinc, manganese, copper, selenium and chromium.Two different experiments were carried out, one with feeding during the pre-slaughter period (7 days) and the other, during a long feeding period (30 days). In each of the experiments, 120 juveniles were used in the finishing phase with an average weight of 360.6 g, randomly distributed in 12 boxes of 1000 L in a closed circulation system. Parameters of fillet quality in the pre-slaughter period (7 days) were evaluated: hydrogen potential (pH), fillet yield, color, cooking loss, weight loss by defrosting (drip loss) and retention capacity of water (CRA). The analyzes in the period after 30 days of feeding were the same as in the pre-slaughter period with the addition of: production performance parameters (weight gain, feed conversion and specific growth rate), fillet texture, lipid oxidation (... (Complete abstract click electronic access below)
Mestre
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AlSaleh, Saja. "Relationship between breast milk fatty acids and infant bone mass and metabolism." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106517.
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The primary objective of this thesis was to determine if long chain polyunsaturated fatty acids (LCPUFA) in maternal milk relates to infant bone mineral content, density and metabolism. A cohort of healthy singleton breastfed infants (n=120) were studied at 1 month post-partum. The measurements included anthropometric measurements of both mother and infant. Maternal dietary intake was assessed using both a 24-h recall and a food frequency questionnaire. A representative breast milk sample was collected for measurement of LCPUFA. Infant bone mineral content and density were assessed using dual-energy x-ray absorptiometry along with plasma parathyroid hormone, 25-hydroxyvitamin D and ionized calcium, plus urinary calcium:creatinine. Infant size at birth and 1 mo were within 2 SD of the World Health Organization growth standard. Maternal intake of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) during pregnancy (r = 0.42, p<0.0001; r = 0.46, p<0.0001; respectively) directly associated with milk LCPUFA composition. Maternal intake of DHA and EPA the day before showed similar results (r = 0.43, p<0.0001; r = 0.51, p<0.0001; respectively). Correlation analysis revealed a negative correlation between breast milk DHA and arachidonic acid (AA) with the infant lumbar spine vertebrate 1-4 bone mineral content (BMC) (r = - 0.18, p = 0.05; r = - 0.19, p = 0.04; respectively) but these relationships were not evident in multivariate analyses. In multivariate analysis, adjusted for infants' weight, age, gender, ethnicity, vitamin D supplementation and maternal smoking and pre-pregnancy body mass index (BMI), breast milk LCPUFA was not related to infant bone mineral density (BMD) nor BMC. Based on the multivariate analysis, breast milk LCPUFA do not explain the variance in bone mass early post-natally. However, since dietary intake may not reflect LCPUFA status, further studies are warranted using measures of infant LCPUFA status along with bone mass to confirm these observations.L'objectif principal de cette thèse était de déterminer si longue chaîne d'acides gras polyinsaturés (AGPI-LC) dans le lait maternel se rapporte à la teneur en minéraux des os du nourrisson, la densité et le métabolisme. Une cohorte de santé Singleton nourrissons allaités (n = 120) ont été étudiés à 1 mois post-partum. Les mesures comprenaient des mesures anthropométriques de la mère et du nourrisson. Maternelle apport alimentaire a été évaluée en utilisant à la fois un rappel de 24 h et un questionnaire de fréquence alimentaire. Un échantillon de lait maternel représentatifs ont été recueillis pour la mesure de AGPILC. Le contenu minéral osseux et la densité du nourrisson ont été évaluées en utilisant la bi-énergie absorptiométrie à rayons X avec l'hormone parathyroïdienne plasma, 25-hydroxyvitamine D et le calcium ionisé, plus de calcium urinaire: créatinine. La taille du nourrisson à la naissance et 1 mois étaient à moins de 2 SD de la norme de croissance mondiale de la Santé Organisation. Apport de la mère de l'acide docosahexaénoïque (DHA) et l'acide eicosapentaénoïque (EPA) pendant la grossesse (r = 0,42, p <0,0001, r = 0,46, p <0,0001; respectivement) directement associés avec le lait AGPILC composition. Apport de la mère de DHA et d'EPA la veille a montré des résultats similaires (r = 0,43, p <0,0001, r = 0,51, p <0,0001; respectivement). L'analyse de corrélation a révélé une corrélation négative entre le lait maternel DHA et acide arachidonique (AA) avec la colonne vertébrale lombaire infantile vertébrés 1-4 contenu minéral osseux (CMO) (r = - 0,18, p = 0,05, r = - 0,19, p = 0,04; respectivement), mais ces relations ne sont pas évidentes dans les analyses multivariées. En analyse multivariée, ajustée pour le poids des nourrissons, âge, sexe, origine ethnique, supplémentation en vitamine D et le tabagisme maternel et pré-grossesse indice de masse corporelle (IMC), le lait maternel AGPILC n'était pas liée à la densité minérale osseuse du nourrisson (DMO), ni BMC. Basé sur l'analyse multivariée, le lait maternel AGPILC n'expliquent pas la variance de la masse osseuse précoce post-natale. Toutefois, depuis l'apport alimentaire peut ne pas refléter l'état AGPILC, nouvelles études sont justifiées par des mesures d'AGPILC état infantile ainsi que la masse osseuse pour confirmer ces observations.
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Murphy, Jessica. "Whole-body protein metabolism in obese elderly women with type 2 diabetes." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97068.
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Obesity and type 2 diabetes (T2DM) have been shown to alter protein and glucose metabolism in young adults, but whether these findings translate to the elderly remains unknown. Accordingly, we assessed whole-body protein (13C-leucine) and 3-3H-glucose kinetics in 10 healthy, 7 obese and 8 obese, type 2 diabetic (OB-T2D) elderly women in the postabsorptive state and during a hyperinsulinemic, euglycemic, isoaminoacidemic clamp. Postabsorptive protein kinetics per kg fat free mass did not differ among groups. During the clamp, however, net protein balance was significantly greater in healthy than obese and OB-T2D women, who both failed to achieve net protein anabolism. This protein insensitivity to insulin paralleled a blunted insulin-mediated glucose disposal rate in obese and OB-T2D women. Hence, the insulin resistance of protein and glucose metabolism may influence dietary needs in obese elderly women, regardless of the presence of T2DM, and should be addressed in their management.Il a été démontré que l'obésité et le diabète de type 2 (DT2) altèrent le métabolisme protéique et glucidique chez le jeune adulte mais nous ne savons pas si ces résultats s'appliquent aux aînés. Par conséquent, nous avons mesuré les cinétiques globales des protéines (13C-leucine) et du glucose (3-3H-glucose) chez 10 femmes en santé, 7 obèses et 8 obèses ayant du diabète (OB-DT2) à jeun et durant un test de verrouillage (clamp) hyperinsulinémique, euglycémique et isoaminoacidémique. Les cinétiques des protéines à jeun par kg de masse maigre ne différèrent pas entre les groupes. Par contre, durant le clamp, le bilan protéique net était significativement plus élevé chez les femmes en santé que chez les obèses ou les OB-DT2, ces deux groupes n'ayant pas pu atteindre l'anabolisme protéique net. Parallèlement, les taux d'utilisation du glucose étaient moindres chez les femmes obèses et les OB-DT2. En somme, la résistance à l'insuline des protéines et du glucose peut influencer les besoins nutritionnels des femmes âgées obèses, peu importe si le diabète est présent, et devrait servir de cible thérapeutique.
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Teff, Karen. "Relationships between tryptophan, diet, 5-hydroxytryptamine metabolism, 5-hydroxytryptamine function and behavior." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74369.
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The role of tryptophan availability in the regulation of 5-hydroxytryptamine (5HT) metabolism and function has been examined in rats and humans, by manipulation of dietary components. It was demonstrated that in the rat, protein and carbohydrate can alter 5HT levels in peripheral tissues as well as brain. A new method for the determination of 5HT in the cisternal cerebrospinal fluid (CSF) of the rat was developed and used as an index of functional 5HT, using pharmacological agents known to act on 5HT function. Using this technique, it was then shown that tryptophan administration potentiates the release of 5HT when the animals are aroused, and thus when their 5HT neurons are firing at high rates. However, the smaller changes in brain 5HT after ingestion of protein or carbohydrate did not lead to altered CSF 5HT. In humans, similar conclusions were drawn. The administration of an amino acid mixture deficient in tryptophan significantly altered macronutrient selection, a behavior thought to be mediated by lowered tryptophan availability and 5HT function. However, when protein or carbohydrate breakfasts were given, no effect on macronutrient selection was observed, suggesting that the physiological changes resulting from dietary intake were not affecting functional 5HT. The final study measured amine precursors and metabolites in human lumbar CSF after the administration of protein or carbohydrate breakfasts and supported this hypothesis. No effects on CSF tryptophan or 5-hydroxyindoleacetic acid, the major metabolite of 5HT, were observed. In conclusion, the results of these studies suggest that, though large changes in precursor availability can alter 5HT function, the effects of dietary intake on 5HT metabolism are not normally of sufficient magnitude to alter 5HT function in rats or humans, or brain 5HT metabolism in humans.
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Winter, Aaron. "Protein metabolism and insulin resistance in non-small cell lung cancer cachexia." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97084.
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Cancer cachexia is characterized by weight loss and insulin resistance. Previous work has shown blunted protein anabolism in insulin resistant conditions. This study tested whether hyperaminoacidemia with hyperinsulinemia elicits blunted whole-body protein anabolism in cachectic non-small cell lung cancer (NSCLC). Whole-body [13C]leucine and [3H]glucose kinetics were assessed in 8 NSCLC patients and 10 age and weight-matched controls during a euglycemic, hyperinsulinemic, clamp with isoaminoacidemia (Iso-AA), followed by hyperaminoacidemia (Hyper-AA). Glucose utilization increased from Iso-AA to Hyper-AA but was lower in NSCLC patients. During Iso-AA, protein breakdown decreased and synthesis was unchanged resulting in positive net balance that was lower in NSCLC patients. During Hyper-AA, synthesis increased but breakdown was unchanged resulting in increased net balance in both groups. In summary, weight-losing NSCLC patients demonstrate insulin resistance of whole-body glucose and protein metabolism. Physiologic hyperaminoacidemia normalized their anabolic response to that of controls and did not impair insulin sensitivity of glucose.La perte de poids et la résistance à l'insuline caractérisent la cachexie due au cancer. Un anabolisme protéique amoindri a été démontré dans des conditions d'insulino-résistance. Cette étude a évalué si l'hyperaminoacidemie et l'hyperinsulinemie résultent en un défaut de l'anabolisme protéique corporel dans la cachexie due au cancer du poumon « non à petites cellules » (NSCLC). La cinétique des protéines ([13C]leucine) et du [3H]glucose corporels ont été évalués chez 8 patients avec NSCLC et 10 hommes en santé, d'âge et de poids similaires, à l'aide du clamp hyperinsulinique, euglycémique, isoaminoacidémique (Iso-AA), suivi d'une hyperaminoacidémie (Hyper-AA). L'utilisation du glucose a augmenté entre Iso-AA et Hyper-AA, mais il était plus bas chez les patients NSCLC. Pendant Iso-AA, la dégradation des protéines a diminué et la synthèse n'a pas changé, résultant en une balance positive moindre chez les NSCLC. En Hyper-AA, la synthèse a augmenté, mais la dégradation n'a pas changé, ce qui a augmenté davantage la balance positive, dans les deux groupes. En résumé, les patients NSCLC perdant du poids ont démontré une résistance du métabolisme glucidique et protéique à l'insuline. L'hyperaminoacidémie a normalisé leur réponse anabolique à celle des contrôles sans affecter la sensibilité du glucose à l'insuline.
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El-Jouni, Zeinab Ezzuddine. "Cholesterol and lipoprotein metabolism of human promyelocytic leukemic HL-60 induced macrophages." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185557.
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Human promyelocytic leukemic cells (HL-60) possess well regulated expression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, acylCoA:cholesterol acyltransferase (ACAT), and receptor-mediated low density lipoprotein (LDL) catabolism, but lack receptor-mediated acetyl-LDL processing. Differentiation of HL-60 cells with tetramyristic phorbol acetate (TPA) is accompanied by the loss of receptor-mediated LDL degradation and no expression of a functionally active scavenger receptor. 1,25-Dihydroxyvitamin D₃ (D₃)-induced HL-60 macrophages possess specific and saturable receptor-mediated binding for LDL, with an apparent K(d) of 29 μg/ml and a B(max) of 219 ng/mg. Receptor-mediated LDL degradation is specific for apoB and apoE containing lipoproteins; it is calcium dependent, and is inhibited by pronase and chloroquine. Differentiation of HL-60 cells with D₃ for 2 days induces a 45-fold increase in acetyl-LDL degradation rate compared to undifferentiated cells. Receptor-mediated degradation of acetyl-LDL is specific for acetyl-LDL, calcium independent, inhibited by chloroquine, pronase and fucoidin treatment, and is not regulated by cellular cholesterol. Acetyl-LDL binding studies demonstrated a K(d) of 36 μg/ml and a B(max) 313 ng/mg. Delivery of cholesterol via receptor-mediated catabolism of LDL or acetyl-LDL results in significant suppression of sterol synthesis and HMG-CoA reductase activity, and significant induction of ACAT activity relative to macrophages incubated with LPDS (P < 0.001). However, receptor-mediated degradation of acetyl-LDL, but not LDL, significantly increases cholesteryl ester content (P < 0.001). D₃-induced HL-60 macrophages incubated with or without LDL for 48 hr exhibited large empty vacuoles with little or no lipid stainable material. In contrast, macrophages incubated with acetyl-LDL exhibited a dramatic increase in lipid stainable material which imparted the macrophages with a foamy appearance. In conclusion, HL-60 cells treated with D₃ for 48 hr undergo activation differentiation assuming the structural and functional characteristics of human monocyte-derived macrophages. Thus, D₃-induced HL-60 macrophages are a suitable in vitro system to study lipoproteins and cholesterol regulation as related to macrophage involvement in atherosclerosis.
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Kim, Eun Joong. "Growth and metabolism of forage-fed beef animals." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366568.
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Lanoue, Louise. "The effects of graded levels of dietary carbohydrate on fetal and neonatal glucose metabolism." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41670.
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The effects of maternal dietary glucose restriction on reproductive performance were investigated by feeding pregnant rats isocaloric diets containing graded levels of dietary glucose (0, 12, 24 and 60%) during pregnancy and during pregnancy and lactation, and by measuring the effects of glucose restriction on (1) maternal, fetal and neonatal metabolism, on (2) growth and composition of the mammary glands and placentas, and (3) on milk composition. Carbohydrate restriction induced maternal metabolic adaptations that were proportional to the severity of the glucose restriction. Placental growth and composition as well as mammary gland composition were not affected by dietary glucose restriction, whereas fetal growth and development and milk composition were significantly impaired when glucose was limited in the maternal diet. This suggests that the effects of dietary glucose on the fetus and on milk composition were not mediated by changes in placenta and mammary gland DNA, protein or glycogen concentrations. Complete dietary glucose restriction significantly depressed fetal liver, lung and heart glycogen concentrations; repletion of the maternal diets with 12 and 24% glucose restored cardiac glycogen to normal but not fetal lung glycogen and liver glycogen. Pups born to dams fed a glucose-free diet failed to survive longer than 24 h postpartum and that was associated with the low levels of tissue glycogen at birth in these pups. At birth, lung and liver glycogen concentration of pups of the 12 and 24% glucose diets was similar to pups of the control diet despite the fact that these reserves were depressed in utero; and these pups efficiently corrected the transient hypoglycemia observed following parturition. The effects of glucose restriction on fetal liver glycogen were not reflected by similar changes in fetal plasma insulin, glucagon and glucose levels or in glycogen synthase and phosphorylase activities. Maternal dietary glucose was an important determinant
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Bayley, Timothy M. "The longer term effect of early dietary cholesterol on cholesterol metabolism in infants /." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37522.
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La synthese endogene du cholesterol (CH) a ete etudie chez 81 nouveau-nes, ages de 4 mois (BRAS 1) ou de 11 a 12 mois (BRAS2), afin d'evaluer les effets a long terme d'un supplement de CH sur l'homeostasie du CH. BRAS 1 etait compose de 32 nouveau-nes recevant soit du lait humain (HUM) (6M, 7F), une formule a base de lait de vache (VAC) (6M, 3F) contenant 3.5 mg CH/dl, ou une formule a base de lait de vache modifiee (VACM) (6M, 7F) contenant 13.5 mg CH/dl, afin d'evaluer l'effet du supplement sur les taux de synthese du CH. BRAS2 etait compose de 49 autres enfants recevant soit HUM (11M, 6F), VAC (7M, 12F) ou VACM (6M, 7F) jusqu'a l'age de 6 mois dans le but d'evaluer une hypothese d'impression genetique. Ceci a ete realise en utilisant un design "cross-over" et en montant un defi journalier de 250 g de CH a l'age de 11 mois. Le taux d'incorporation de deuterium, provenant des reserves d'eau corporelle, dans la structure du CH a servi comme indice du taux de synthese fractionnel (TSF) de ce dernier sur une periode de 48 heures. Les niveaux de CH total et LDL etaient considerablement eleves dans HUM en comparaison avec VAC et VACM a l'age de 4 mois. La concentration sanguine du CH etait semblable a 11 et 12 mois. Le TSF etait 4 fois plus eleve dans VAC et VACM relatif a HUM, mais il n'y avait pas de difference entre VAC et VACM a 11 et 12 mois. Cependant, les TSF de 4 a 12 mois ont augmente dans HUM et baisse dans VAC et VACM. Nos resultats indiquent qu'independamment du contenu des dietes, le defi journalier de CH n'as pas eu d'effet considerable ni sur les taux de synthese, ni sur les niveaux de CH sanguin. Ces resultats appuient l'idee que le CH alimentaire n'a que des effets minimes sur le metabolisme a long terme du CH.
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Davies, Isobel R. "The food energy values of unavailable carbohydrate assessed in the rat." Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236345.
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