Journal articles: 'GRP'

1

Bányai, Krisztián, Ágnes Bogdán, György Szücs, Serenella Arista, Simona De Grazia, Gagandeep Kang, Indrani Banerjee, Miren Iturriza-Gómara, Canio Buonavoglia, and Vito Martella. "Assignment of the group A rotavirus NSP4 gene into genotypes using a hemi-nested multiplex PCR assay: a rapid and reproducible assay for strain surveillance studies." Journal of Medical Microbiology 58, no. 3 (March 1, 2009): 303–11. http://dx.doi.org/10.1099/jmm.0.005124-0.

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The rotavirus non-structural protein NSP4 has been implicated in a number of biological functions during the rotavirus cellular cycle and pathogenesis, and has been addressed as a target for vaccine development. The NSP4 gene has been classified into six genotypes (A–F). A semi-nested triplex PCR was developed for genotyping the major human NSP4 genotypes (A–C), which are common in human rotavirus strains but are also shared among most mammalian rotavirus strains. A total of 192 previously characterized human strains representing numerous G and P type specificities (such as G1P[8], G1P[4], G2P[4], G3P[3], G3P[8], G3P[9], G4P[6], G4P[8], G6P[4], G6P[9], G6P[14], G8P[10], G8P[14], G9P[8], G9P[11], G10P[11], G12P[6] and G12P[8]) were tested for NSP4 specificity by the collaborating laboratories. An additional 35 animal strains, including the reference laboratory strains SA11 (simian, G3P[2]), NCDV (bovine, G6P[1]), K9 and CU-1 (canine, G3P[3]), together with 31 field isolates (canine, G3P[3]; feline, G3P[9]; porcine, G2P[23], G3P[6], G4P[6], G5P[6], G5P[7], G5P[26], G5P[27], G9P[6] and G9P[7]) were also successfully NSP4-typed. Four human G3P[9] strains and one feline G3P[9] strain were found to possess an NSP4 A genotype, instead of NSP4 C, suggesting a reassortment event between heterologous strains. Routine NSP4 genotyping may help to determine the genomic constellation of rotaviruses of man and livestock, and identify interspecies transmission of heterologous strains.

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Glover, Sarah, Rajkumar Nathaniel, Lubna Shakir, Cecile Perrault, Rebecca K. Anderson, Roger Tran-Son-Tay, and Richard V. Benya. "Transient upregulation of GRP and its receptor critically regulate colon cancer cell motility during remodeling." American Journal of Physiology-Gastrointestinal and Liver Physiology 288, no. 6 (June 2005): G1274—G1282. http://dx.doi.org/10.1152/ajpgi.00108.2004.

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Gastrin-releasing peptide (GRP) is typically viewed as a growth factor in cancer. However, we have suggested that in colon cancer, GRP acts primarily as a morphogen when it and its receptor (GRP-R) are aberrantly upregulated. As such, GRP/GRP-R act(s) primarily to modulate processes contributing to the assumption or maintenance of tumor differentiation. One of the most important such processes is the ability of tumor cells to achieve directed motility in the context of tissue remodeling. Yet the cellular conditions affecting GRP/GRP-R expression, and the biochemical pathways involved in mediating its morphogenic properties, remain to be established. To study this, we evaluated the human colon cancer cell lines Caco-2 and HT-29 cells. We found that confluent cells do not express GRP/GRP-R. In contrast, disaggreation and plating at subconfluent densities results in rapid GRP/GRP-R upregulation followed by their progressive decrease as confluence is achieved. GRP/GRP-R coexpression correlated with that of focal adhesion kinase (FAK) phosphorylation of Tyr397, Tyr407, Tyr861, and Tyr925 but not Tyr576 or Tyr577. To more specifically evaluate the kinetics of GRP/GRP-R upregulation, we wounded confluent cell monolayers. At t = 0 h GRP/GRP-R were not expressed, yet cells immediately began migrating into the gap created by the wound. GRP/GRP-R were first detected at ∼2 h, and maximal levels were observed at ∼6 h postwounding. The GRP-specific antagonist [d-Phe6]-labeled bombesin methyl ester had no effect on cell motility before GRP-R expression. In contrast, this agent increasingly attenuated cell motility with increasing GRP-R expression such that from t = 6 h onward no further cell migration into the gap was observed. Overall, these findings indicate the existence of GRP-independent and -dependent phases of tumor cell remodeling with the latter mediating colon cancer cell motility during remodeling via FAK.

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Koceić Bilan, Nikola, and Ivančica Mirošević. "Functorial reducing pro⁎-Grp category to pro-Grp." Topology and its Applications 263 (August 2019): 74–89. http://dx.doi.org/10.1016/j.topol.2019.05.018.

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Lee, Young-Geun, Sun-Hee Kim, Joon-Seok Park, and Soon-Jong Yoon. "Pipe Stiffness Prediction of GRP Flexible Pipe." Journal of the Korean Society for Advanced Composite Structures 2, no. 3 (September 30, 2011): 18–24. http://dx.doi.org/10.11004/kosacs.2011.2.3.018.

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Левкина and Nataliya Levkina. "The Contribution of New Postindustrial Technological Modes to per Capita GRP of the Urals Federal District`s Regions of the Russian Federation." Economics 4, no. 6 (December 9, 2016): 63–67. http://dx.doi.org/10.12737/22928.

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The article presents the results of the analysis of technological modes` productivity in the economy of the Urals Federal District. The use of evaluation of contribution to per capita GDP industrial (relict and fourth) technological modes and specified data on the gross regional product has allowed to establish that the spread of new postindustrial technological modes in the economy of different regions of the Urals Federal District is uneven. In Kurgan region the postindustrial technological modes are not widespread. The contribution of new modes in per capita GRP in Chelyabinsk region in 2014 reached 115865,55 rubles (29.99% of per capita GRP), in Sverdlovsk region — 251945,45 rubles (48,21% of per capita GRP), in Tyumen region as a whole — 1705575,89 rubles (86,31% of per capita GRP), in Tyumen region except for Khanty-Mansi and Yamal-Nenets Autonomous Areas — 439298,25 rubles (61,88% of per capita GRP). The contribution of new modes in per capita GRP in Khanty-Mansi Autonomous Area in 2014 reached 2124572,44 rubles (88,70% of per capita GRP), in Yamal-Nenets Autonomous Area — 3789418,62 rubles (93,09% of per capita GRP). The system of new technological modes uses 3-19% of the resources of the Urals Federal District`s regions.

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Oh, Jin-Oh, and Sung-Ho Yoon. "Measurements of Thermal Expansion Coefficients in GRP Pipe." Journal of The Korean Society for Composite Materials 25, no. 1 (February 28, 2012): 26–30. http://dx.doi.org/10.7234/kscm.2012.25.1.026.

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7

Hollaway, L. "GRP and Buildings." Composites 16, no. 1 (January 1985): 56. http://dx.doi.org/10.1016/0010-4361(85)90662-7.

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Kim, Sun-Hee, Young-Geun Lee, Hyung-Jung Joo, Nam-Jin Jung, and Soon-Jong Yoon. "Prediction of Ring Deflection GRP Pipe Buried Underground." Journal of the Korean Society for Advanced Composite Structures 4, no. 3 (September 30, 2013): 38–44. http://dx.doi.org/10.11004/kosacs.2013.4.3.038.

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9

Zakharzhevskaya, A. Yu. "Disparities of China’s regions development: dependence on the sectoral economic structure." Regional nye issledovaniya 71, no. 1 (2021): 84–95. http://dx.doi.org/10.5922/1994-5280-2021-1-7.

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The article explores the dynamics of changes in disparities of China’s regions’ economic level. According to a number of researchers, economic disparities between China’s regions started to decrease from about the mid-2000s. To clarify this picture the article uses indicator of contribution of the region’s GRP to the country’s total GRP. As a result of the research carried out by the author, it was found that in the PRC there really was a period when the economic gap between regions was narrowing down, but in general, changes in the relative contribution of regions to the country’s GRP are more complex than just a decrease or increase in economic disparities. Also, based on statistical data, the article draws conclusions about the relationship between the dynamics of the region’s contribution to the total GRP and the shares of the secondary and tertiary sectors in the region’s economy. It turned out that the increase in the economic level of the region in comparison with other regions is closely related to the share of the secondary sector in the GRP of this region: in most regions of China, the increase in the share of the secondary sector occurs in parallel with the growth of the contribution of the region’s GRP to the total GRP of the country. The growth in the share of the tertiary sector, on the contrary, in most cases is accompanied by a relative decrease in the economic level of the region, that is, its contribution to the total GRP decreases.

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10

Gawin, A. Z., J. N. Baraniuk, J. D. Lundgren, and M. Kaliner. "Effects of gastrin-releasing peptide and analogues on guinea pig nasal mucosal secretion." American Journal of Physiology-Lung Cellular and Molecular Physiology 264, no. 4 (April 1, 1993): L345—L350. http://dx.doi.org/10.1152/ajplung.1993.264.4.l345.

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The effects of gastrin-releasing peptide (GRP), bombesin, GRP-(1–16) and GRP-(21–27) on guinea pig nasal mucosal secretion were studied in vivo. GRP, bombesin, and GRP-(21–27) induced significant secretion of total protein, albumin, and alkaline phosphatase. GRP induced significant secretion at lower concentrations (10(-11) and 10(-10) M) than were required for bombesin and GRP-(21–27) (10(-7) M). GRP-(1–16) did not stimulate secretion, indicating that the COOH-terminal region of GRP contained the secretagogic principle. Capsaicin, a stimulant of nociceptive sensory nerves, stimulated GRP release into nasal secretions. These data suggest that GRP is present in guinea pig nasal mucosa and that the COOH-terminal region of GRP may regulate mucosal macromolecule secretion.

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11

García, B. Benítez, F. Moreno Ramos, MA González Fernández, L. González del Valle, E. Capilla Santamaría, T. Perez Robles, and A. Herrero Ambrosio. "GRP-035 Boceprevir and Telaprevir: Safety: Abstract GRP-035 Table 1." European Journal of Hospital Pharmacy 20, Suppl 1 (March 2013): A13.1—A13. http://dx.doi.org/10.1136/ejhpharm-2013-000276.035.

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12

Moreno, M., A. Gil, R. Diez, and T. Molina. "GRP-059 Ethanol Content in Chemotherapy: Abstract GRP-059 Table 1." European Journal of Hospital Pharmacy 20, Suppl 1 (March 2013): A21.3—A22. http://dx.doi.org/10.1136/ejhpharm-2013-000276.059.

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13

Ladenheim, E. E., J. E. Taylor, D. H. Coy, K. A. Moore, and T. H. Moran. "Hindbrain GRP receptor blockade antagonizes feeding suppression by peripherally administered GRP." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 271, no. 1 (July 1, 1996): R180—R184. http://dx.doi.org/10.1152/ajpregu.1996.271.1.r180.

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Bombesin (BN)-like peptides injected peripherally or centrally suppress food intake in rats. The relationship between the central and peripheral actions of BN is unknown. However, experimental evidence supports a critical role for the caudal hindbrain in mediating the feeding effects of BN. To investigate this relationship further, we examined the ability of fourth ventricular infusion of a specific gastrin-releasing peptide (GRP) antagonist, [D-F5, Phe6, D-Ala11]BN-(6-13) methyl ester (BN-ME), to block suppression of glucose intake (0.5 kcal/ml) produced by intraperitoneal administration of GRP-(18-27) in 5-h food-deprived male Sprague-Dawley rats (n = 10). We found that fourth ventricular administration of 10, 32, and 100 ng BN-ME blocked the suppression of glucose intake produced by peripherally administered 10 nmol/kg GRP-(18-27). The most effective dose of BN-ME (100 ng) blocked the ability of peripheral injection of GRP-(18-27) to inhibit glucose intake but had no effect on intake when given alone. These results demonstrate that the availability of caudal hindbrain GRP receptors is necessary for peripherally administered GRP-(18-27) to reduce food intake in rats.

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14

Whitley, JC, C. Moore, AS Giraud, and A. Shulkes. "Isolation and characterisation of the ovine gastrin-releasing peptide gene; abundant expression in the pregnant uterus and selective expression in fetal tissues." Journal of Endocrinology 175, no. 2 (November 1, 2002): 447–57. http://dx.doi.org/10.1677/joe.0.1750447.

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High concentrations of a peptide related to gastrin-releasing peptide (GRP) are produced in the utero-placental unit of the human and sheep and secreted into the general circulation. This suggests an endocrine role in addition to its role as a neurotransmitter/neuromodulator. The GRP is larger than the previously described form GRP(1-27) but it is not known whether the larger form is the product of a related GRP-like gene or differences in post-translational processing. We have therefore cloned the gene for the sheep homologue of the GRP gene and determined its distribution. Only a single GRP gene was found in the sheep. This had a similar organisation to the human GRP gene with three exons and two introns. The larger form of GRP in the pregnant endometrium therefore appears to be the result of an alteration in processing of the GRP prohormone. The expression of GRP mRNA in the pregnant uterus was extraordinarily high comprising one-third of all mRNA synthesised by the pregnant endometrium. As the endometrial GRP mRNA arises solely from the glandular epithelium, the localised synthesis of GRP mRNA would be far higher. GRP mRNA was expressed in a wide variety of fetal tissues (fundus, colon, jejunum, ileum, duodenum, kidney, adrenal, lung, heart and pancreas) with a corresponding presence of GRP immunoreactivity. The expression of GRP in the fetal lung was biphasic with peaks at mid-term and near parturition but none in the adult supporting the concept of a specific developmental role of GRP in the lung.

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Persson, Kristin, Ronald L. Gingerich, Sonali Nayak, Keiji Wada, Etsuko Wada, and Bo Ahrén. "Reduced GLP-1 and insulin responses and glucose intolerance after gastric glucose in GRP receptor-deleted mice." American Journal of Physiology-Endocrinology and Metabolism 279, no. 5 (November 1, 2000): E956—E962. http://dx.doi.org/10.1152/ajpendo.2000.279.5.e956.

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By applying a newly developed ELISA technique for determining biologically active intact glucagon-like peptide [GLP-1, GLP-1-(7–36)amide] in mouse, plasma baseline GLP-1 in normal NMRI mice was found to be normally distributed (4.5 ± 0.3 pmol/l; n = 72). In anesthetized mice, gastric glucose (50 or 150 mg) increased plasma GLP-1 levels two- to threefold ( P < 0.01). The simultaneous increase in plasma insulin correlated to the 10-min GLP-1 levels ( r = 0.36, P < 0.001; n = 12). C57BL/6J mice deleted of the gastrin-releasing peptide (GRP) receptor by genetic targeting had impaired glucose tolerance ( P = 0.030) and reduced early (10 min) insulin response ( P = 0.044) to gastric glucose compared with wild-type controls. Also, the GLP-1 response to gastric glucose was significantly lower in the GRP receptor-deleted mice than in the controls ( P = 0.045). In conclusion, this study has shown that 1) plasma levels of intact GLP-1 increase dose dependently on gastric glucose challenge in correlation with increased insulin levels in mice, and 2) intact GRP receptors are required for normal GLP-1 and insulin responses and glucose tolerance after gastric glucose in mice.

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Cardona, C., N. M. Bleehen, and J. G. Reeve. "Characterization of ligand binding and processing by gastrin-releasing peptide receptors in a small-cell lung cancer cell line." Biochemical Journal 281, no. 1 (January 1, 1992): 115–20. http://dx.doi.org/10.1042/bj2810115.

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The ligand-binding properties of the gastrin-releasing peptide (GRP) receptor and the cellular processing of GRP have been studied in the small-cell lung cancer (SCLC) cell line COR-L42. Scatchard analysis of GRP receptor expression indicated a single class of high-affinity receptors (Kd 1.5 nM) and approx. 6700 receptors/cell. GRP bound to its receptor with a Ki of 2.4 nM. The bombesin-related peptides neuromedin B (NMB) and phyllolitorin also bound to GRP receptors with Ki values of 22.7 and 59.1 nM respectively. Binding of 125I-GRP to COR-L42 cells increased rapidly at 37 degrees, achieved a maximum at 10 min and declined rapidly thereafter. At 4 degrees C, maximum binding was achieved at 30 min and the subsequent decline in cell-associated radioactivity was slower than that seen at 37 degrees C. Acid/salt extraction, to separate surface-bound ligand from internalized GRP, indicated that after receptor binding 125I-GRP was rapidly internalized. To determine the pathway of 125I-GRP degradation, binding studies were carried out with the lysosomotropic agent chloroquine (5 mM), and with phosphoramidon (10 microM), an inhibitor of the membrane-bound enzyme (EC 3.4.24.11). Both agents markedly inhibited the degradation of GRP, indicating that this process involves a lysosomal pathway and a phosphoramidon-sensitive pathway, possibly involving the EC 3.4.24.11 enzyme. GRP receptor down-regulation was observed following a 10 min exposure to 100 nM-GRP. With longer pretreatment times the number of binding sites recovered to 80% of control values. Treatment with 5 mM-chloroquine plus GRP or cycloheximide (10 micrograms/ml) plus GRP demonstrated that the majority of GRP receptors are recycled. NMB and phyllolitorin pretreatment did not influence the subsequent binding of 125I-GRP, suggesting that these peptides do not down-regulate GRP receptors.

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Traynor, T. R., and S. M. O'Grady. "Regulation of colonic ion transport by GRP. II. GRP modulates the epithelial response to PGE2." American Journal of Physiology-Cell Physiology 270, no. 3 (March 1, 1996): C859—C865. http://dx.doi.org/10.1152/ajpcell.1996.270.3.c859.

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The purpose of this study was to examine the potential modulatory effects of gastrin-releasing peptide (GRP) on prostaglandin (PG) E2-stimulated electrolyte transport across the distal colon epithelium. In an earlier study, PGE2 was shown to reduce net Cl absorption without altering the serosal-to-mucosal unidirectional Cl flux in porcine distal colon (19). In the present study, tissues were pretreated with serosal or mucosal GRP and subsequently stimulated with PGE2. The resulting increase in short-circuit current (ISC) was 152% (serosal GRP) and 49% (mucosal GRP) greater than control PGE2 responses alone. Serosal, but not mucosal, GRP also enhanced the ISC response to vasoactive intestinal peptide. On the basis of flux measurements, the combined effects of serosal GRP and PGE2 resulted in the activation of a transcellular pathway for Cl secretion, which was not activated by either mediator alone. The time course of the PGE2 response was also affected by GRP. Serosal GRP shortened the time to maximum ISC by 35%, whereas mucosal peptide lengthened the time to maximum ISC by 68% These results suggest that GRP acts as a modulator of PG action on electrolyte transport in the distal colon.

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Traynor, T. R., and S. M. O'Grady. "Regulation of colonic ion transport by GRP. I. GRP stimulates transepithelial K and Na secretion." American Journal of Physiology-Cell Physiology 270, no. 3 (March 1, 1996): C848—C858. http://dx.doi.org/10.1152/ajpcell.1996.270.3.c848.

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Regulation of electrolyte transport across porcine distal colon epithelium by gastrin-releasing peptide (GRP) was examined using mucosal sheets mounted in Ussing chambers. Serosal GRP produced a biphasic response consisting of a transient increase in short-circuit current (ISC) followed by a long-lasting decrease. Indomethacin and tetrodotoxin inhibited the ISC increase without affecting the secondary decrease. Addition of GRP to the mucosal solution produced a decrease in ISC similar to that observed with serosal treatment, but no transient increase in ISC was observed. GRP and bombesin (50% effective concentrations of 26 and 30 nM, respectively) were more effective than neuromedin B in decreasing the ISC, and the GRP receptor antagonist [D-Phe(6)]bombesin(6-13)-O-methyl produced a sixfold dextral shift in the GRP concentration-response relationship. The GRP-stimulated decrease was reduced in the absence of Cl and by serosal bumetanide. Flux measurements showed that GRP increased Rb and Na secretion while having no effect on transepithelial Cl transport. Phosphoinositide turnover was increased by GRP, suggesting that the ion transport changes may be mediated by intracellular Ca concentration. The results of this study demonstrate that GRP stimulates K and Na secretion across the porcine distal colon epithelium and that these processes are dependent, in part, on a bumetanide-sensitive transport pathway located in the basolateral membrane.

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19

Gontcharov, George A., and Aleksandr V. Mosenkov. "Gaia DR2 giants in the Galactic dust – II. Application of the reddening maps and models." Monthly Notices of the Royal Astronomical Society 500, no. 2 (September 9, 2020): 2607–19. http://dx.doi.org/10.1093/mnras/staa2728.

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ABSTRACT We exploit a complete sample of 101 810 Gaia DR2 giants, selected in Paper I in the space cylinder with a radius of 700 pc around the Sun and a height of |Z| = 1800 pc, using the Gaia DR2 parallaxes, GBP and GRP photometry, and WISE W3 photometry. We explain the spatial variations of the modes of the observables GBP − GRP and GRP − W3 by the spatial variations of the corresponding reddenings described in the GM20 3D dust distribution model. Presented in this paper, GM20 is an advanced version of the model introduced by Gontcharov in 2009. GM20 proposes two intersecting dust layers, along the Galactic mid-plane and in the Gould Belt, with exponential vertical and sinusoidal longitudinal variations of the dust spatial density in each layer. The Belt layer is an ellipse, oriented nearly between the centre and anticentre of the Galaxy, and with semi-major and semi-minor axes of 600 and 146 pc, respectively. GBP − GRP and GRP − W3 give similar solutions, but different equatorial layer scale heights of 150 ± 15 and 180 ± 15 pc, respectively, and $(G_\mathrm{BP}-G_\mathrm{RP})_0=(1.14\pm 0.01)-(0.022\pm 0.010)\, |Z|$, $(G_\mathrm{RP}-W3)_0=(1.44\pm 0.01)-(0.015\pm 0.010)\, |Z|$, where Z is in kpc. We compare GM20 with several 3D reddening models and maps in their ability to predict the observed colour modes. GM20 and the 3D map by Gontcharov appear to be the best among the models and maps, respectively. However, the most reliable models and maps mainly disagree only in their estimates of low reddening, including the reddening across the whole dust layer.

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FELDMAN, M. "GRP and Pavlov's dogs." Gut 49, no. 1 (July 1, 2001): 5–6. http://dx.doi.org/10.1136/gut.49.1.5.

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Pearce, Colin. "Carbon footprint of GRP." Reinforced Plastics 51, no. 8 (September 2007): 8. http://dx.doi.org/10.1016/s0034-3617(07)70229-1.

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Banks, W. M. "GRP in structural engineering." Thin-Walled Structures 3, no. 1 (January 1985): 88–89. http://dx.doi.org/10.1016/0263-8231(85)90025-4.

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Bashford, David. "GRP in structural engineering." Materials & Design 6, no. 3 (June 1985): 137. http://dx.doi.org/10.1016/0261-3069(85)90059-7.

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Roose, Jeroen P. "Lost GRP on cytotoxicity?" Nature Immunology 17, no. 12 (November 16, 2016): 1339–40. http://dx.doi.org/10.1038/ni.3620.

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HOLST, J. J., L. BJØRNSKOV HANSEN, T. W. SCHWARTZ, M. HANSEN, and E. BORCH. "Nature and Release of Products of the GRP Precursor Other than GRP." Annals of the New York Academy of Sciences 547, no. 1 Bombesin-Like (December 1988): 443–44. http://dx.doi.org/10.1111/j.1749-6632.1988.tb23911.x.

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Holst, JJ, L. Bjørnskov Hansen, TW Schwartz, and M. Hansen. "Nature and release of products of the GRP-precursor apart from GRP." Regulatory Peptides 19, no. 1-2 (October 1987): 114. http://dx.doi.org/10.1016/0167-0115(87)90105-4.

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Fleischmann, Achim, Beatrice Waser, and Jean Claude Reubi. "High expression of gastrin-releasing peptide receptors in the vascular bed of urinary tract cancers: promising candidates for vascular targeting applications." Endocrine-Related Cancer 16, no. 2 (June 2009): 623–33. http://dx.doi.org/10.1677/erc-08-0316.

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Tumoral gastrin-releasing peptide (GRP) receptors are potential targets for diagnosis and therapy using radiolabeled or cytotoxic GRP analogs. GRP-receptor overexpression has been detected in endocrine-related cancer cells and, more recently, also in the vascular bed of selected tumors. More information on vascular GRP-receptors in cancer is required to asses their potential for vascular targeting applications. Therefore, frequent human cancers (n=368) were analyzed using in vitro GRP-receptor autoradiography on tissue sections with the 125I-[Tyr4]-bombesin radioligand and/or the universal radioligand 125I-[d-Tyr6, β-Ala11, Phe13, Nle14]-bombesin(6–14). GRP-receptor expressing vessels were evaluated in each tumor group for prevalence, quantity (vascular score), and GRP-receptor density. Prevalence of vascular GRP-receptors was variable, ranging from 12% (prostate cancer) to 92% (urinary tract cancer). Different tumor types within a given site had divergent prevalence of vascular GRP-receptors (e.g. lung: small cell cancer: 0%; adenocarcinoma: 59%; squamous carcinoma: 83%). Also the vascular score varied widely, with the highest score in urinary tract cancer (1.69), moderate scores in lung (0.91), colon (0.88), kidney (0.84), and biliary tract (0.69) cancers and low scores in breast (0.39) and prostate (0.14) cancers. Vascular GRP-receptors were expressed in the muscular vessel wall in moderate to high densities. Normal non-neoplastic control tissues from these organs lacked vascular GRP-receptors. In conclusion, tumoral vessels in all evaluated sites express GRP-receptors, suggesting a major biological function of GRP-receptors in neovasculature. Vascular GRP-receptor expression varies between the tumor types indicating tumor-specific mechanisms in their regulation. Urinary tract cancers express vascular GRP-receptors so abundantly, that they are promising candidates for vascular targeting applications.

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Lebacq-Verheyden, Anne-Marie, Shoshana Segal, Frank Cuttitta, and James F. Battey. "Swiss 3T3 mouse embryo fibroblasts transfected with a human prepro-GRP gene synthesize and secrete pro-GRP rather than GRP." Journal of Cellular Biochemistry 36, no. 3 (March 1988): 237–48. http://dx.doi.org/10.1002/jcb.240360305.

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LeSauter, Joseph, Rae Silver, Robin Cloues, and Paul Witkovsky. "Light exposure induces short- and long-term changes in the excitability of retinorecipient neurons in suprachiasmatic nucleus." Journal of Neurophysiology 106, no. 2 (August 2011): 576–88. http://dx.doi.org/10.1152/jn.00060.2011.

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The suprachiasmatic nucleus (SCN) is the locus of a hypothalamic circadian clock that synchronizes physiological and behavioral responses to the daily light-dark cycle. The nucleus is composed of functionally and peptidergically diverse populations of cells for which distinct electrochemical properties are largely unstudied. SCN neurons containing gastrin-releasing peptide (GRP) receive direct retinal input via the retinohypothalamic tract. We targeted GRP neurons with a green fluorescent protein (GFP) marker for whole cell patch-clamping. In these neurons, we studied short (0.5–1.5 h)- and long-term (2–6 h) effects of a 1-h light pulse (LP) given 2 h after lights off [Zeitgeber time (ZT) 14:00–15:00] on membrane potential and spike firing. In brain slices taken from light-exposed animals, cells were depolarized, and spike firing rate increased between ZT 15:30 and 16:30. During a subsequent 4-h period beginning around ZT 17:00, GRP neurons from light-exposed animals were hyperpolarized by ∼15 mV. None of these effects was observed in GRP neurons from animals not exposed to light or in immediately adjacent non-GRP neurons whether or not exposed to light. Depolarization of GRP neurons was associated with a reduction in GABAA-dependent synaptic noise, whereas hyperpolarization was accompanied both by a loss of GABAA drive and suppression of a TTX-resistant leakage current carried primarily by Na. This suggests that, in the SCN, exposure to light may induce a short-term increase in GRP neuron excitability mediated by retinal neurotransmitters and neuropeptides, followed by long-term membrane hyperpolarization resulting from suppression of a leakage current, possibly resulting from genomic signals.

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Matkowskyj, Kristina A., Kristin Keller, Sarah Glover, Lori Kornberg, Roger Tran-Son-Tay, and Richard V. Benya. "Expression of GRP and Its Receptor in Well-differentiated Colon Cancer Cells Correlates with the Presence of Focal Adhesion Kinase Phosphorylated at Tyrosines 397 and 407." Journal of Histochemistry & Cytochemistry 51, no. 8 (August 2003): 1041–48. http://dx.doi.org/10.1177/002215540305100807.

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Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are not normally expressed by epithelial cells lining the colon but are aberrantly expressed in cancer, where they act as morphogens and regulate tumor cell differentiation. Studies of colon cancer formation in mice genetically incapable of synthesizing GRP-R suggested that this receptor's morphogenic properties were mediated via focal adhesion kinase (FAK). We therefore set out to determine the presence of both total and phosphorylated forms of FAK in human colon cancer specimens as a function of tumor cell differentiation and GRP/GRP-R co-expression. Ten colon cancers containing 25 regions of distinct differentiation were randomly selected from our GI Cancer Tumor Bank. All specimens were immunohistochemically probed using antibodies recognizing GRP, GRP-R, total FAK, and FAK specifically phos-phorylated at tyrosine (Y) 397, 407, 576, 577, 861, and 925. Antibody-specific chromogen was determined by quantitative immunohistochemistry (IHC) for each region of defined differentiation. Here we confirm that GRP/GRP-R co-expression is a function of differentiation, with highest levels observed in well-differentiated tumor cells. We also show that the amount of total FAK and of FAK phosphorylated at Y397 and Y407 tightly correlates with differentiation and with the amount of GRP/GRP-R co-expression. These findings are consistent with GRP/GRP-R acting as a morphogen by activating FAK, and suggest that this occurs via phosphorylation of this enzyme at two specific tyrosine residues.

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Guo, Y. S., L. Mok, C. W. Cooper, G. H. Greeley, J. C. Thompson, and P. Singh. "Effect of gastrin-releasing peptide analogues on gastrin and somatostatin release from isolated rat stomach." American Journal of Physiology-Gastrointestinal and Liver Physiology 253, no. 2 (August 1, 1987): G206—G210. http://dx.doi.org/10.1152/ajpgi.1987.253.2.g206.

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A differential biological potency of bombesin (BBS), compared with its mammalian counterpart gastrin-releasing peptide (GRP), has been reported in several biological systems in rodents. In the present study we have examined the relative potency of BBS, GRP-(1-27) (GRP-L), and GRP-(14-27) (GRP-S) on the release of gastrin and somatostatin (SRIF) from the isolated perfused rat stomachs. Male rats were fasted overnight and the stomachs perfused via the celiac artery. Increasing doses of BBS, GRP-L, and GRP-S were perfused for 15 min each and the effluent collected for measurement of gastrin and SRIF. The release of gastrin and SRIF in response to the GRP analogues was biphasic, with a peak increase occurring within the first 5 min, followed by a sustained increased secretion. The release of gastrin in response to 10(-10)-10(-9) M concentrations of the peptides was strongest with GRP-S (1.5-2.0 times higher than that released by BBS and GRP-L), although at higher concentrations (10(-8) M), the response to all three analogues was similar. The release of SRIF, on the other hand, was significantly higher in the presence of BBS compared with that in response to GRP-S, while GRP-L was ineffective. These studies indicate that the biological potency of BBS compared with its mammalian counterpart, GRP, is different on the two cell populations [gastrin (G) and SRIF (D)].

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Carroll, Robert E., Kristina A. Matkowskyj, Subrata Chakrabarti, Thomas J. McDonald, and Richard V. Benya. "Aberrant expression of gastrin-releasing peptide and its receptor by well-differentiated colon cancers in humans." American Journal of Physiology-Gastrointestinal and Liver Physiology 276, no. 3 (March 1, 1999): G655—G665. http://dx.doi.org/10.1152/ajpgi.1999.276.3.g655.

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Epithelial cells lining the adult human colon do not normally express gastrin-releasing peptide (GRP) or its receptor (GRPR). In contrast, approximately one-third of human colon cancers and cancer cell lines have been shown to express GRP-binding sites. Because GRPR activation causes the proliferation of many cancer cell lines, GRP has been presumed to act as a clinically significant growth factor. Yet GRP has not been shown to be expressed by colon cancers in humans nor has the effect of GRP and/or GRPR coexpression on tumor behavior been investigated. We therefore determined GRP and GRPR expression by immunohistochemistry in 50 randomly selected colon cancers resected between 1980 and 1997, all 37 associated lymph node and liver metastases, and 20 polyps. Tumor sections studied were those that contained the margin and adjacent nonmalignant epithelium. Overall, 84% of cancers aberrantly expressed GRP or GRPR, with 62% expressing both ligand and receptor, whereas expression was not observed in adjacent normal epithelium. Consistent with the previously established mitogenic capabilities of GRP, tissues coexpressing GRP and GRPR were more likely to express proliferating cell nuclear antigen than tissues not expressing both ligand and receptor. Yet GRP/GRPR coexpression was seen with equal frequency in stage A as in stage D cancers and was only detected in 1 in 37 metastases. Furthermore, Kaplan-Meier analysis did not reveal any difference in patient survival between those whose tumors did or did not express GRP/GRPR. In contrast, GRP/GRPR coexpression was found in all well-differentiated tumor regions, whereas poorly differentiated tissues never coexpressed GRP/GRPR. Overall, these data indicate that, although GRP is a mitogen, it is not a clinically significant growth factor in human colon cancers. Rather, the strong association of GRP/GRPR coexpression with tumor differentiation raises the possibility that these proteins primarily act in vivo as morphogens.

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Lundgren, J. D., J. N. Baraniuk, N. L. Ostrowski, M. A. Kaliner, and J. H. Shelhamer. "Gastrin-releasing peptide stimulates glycoconjugate release from feline trachea." American Journal of Physiology-Lung Cellular and Molecular Physiology 258, no. 2 (February 1, 1990): L68—L74. http://dx.doi.org/10.1152/ajplung.1990.258.2.l68.

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The effect of gastrin-releasing peptide (GRP) on respiratory glycoconjugate (RGC) secretion was investigated in a feline tracheal organ culture model. RGC secretion was stimulated by GRP in a dose-dependent fashion at concentrations from 10(-8) to 10(-5) M (range 15-38% increase above control) with a peak effect within 0.5-1 h of incubation. GRP-(14-27), the receptor binding portion of GRP, and the related molecule, bombesin, also stimulated RGC secretion by approximately 20% above control. Acetyl-GRP-(20-27) stimulated RGC release by 10%, whereas GRP-(1-16) was inactive. Autoradiographic studies with 125I-GRP revealed that specific binding was restricted to the submucosal glands and the surface epithelium. A specific radioimmunoassay showed the content of GRP in feline trachea after extraction with ethanol-acetic acid to be 156 +/- 91 fmol/g wet wt. Indirect immunohistochemistry indicated that ganglion cells located just outside the cartilage contained GRP-immunoreactive materials. GRP is a novel mucus secretagogue that may participate in regulating airway mucosal gland secretion.

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Holst, J. J., S. Knuhtsen, C. Orskov, T. Skak-Nielsen, S. S. Poulsen, S. L. Jensen, and O. V. Nielsen. "GRP nerves in pig antrum: role of GRP in vagal control of gastrin secretion." American Journal of Physiology-Gastrointestinal and Liver Physiology 253, no. 5 (November 1, 1987): G643—G649. http://dx.doi.org/10.1152/ajpgi.1987.253.5.g643.

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We extracted gastrin-releasing peptide (GRP) and its C-terminal decapeptide corresponding to 6.4 and 6.8 pmol/g from pig antrum mucosa. By immunohistochemistry GRP was localized to mucosal, submucosal, and myenteric nerve fibers. A few nerve cell bodies were also identified. Using isolated perfused pig antrum with intact vagal innervation, we found concomitant, atropine-resistant release of GRP and gastrin during electrical stimulation of the vagal nerves. Intra-arterial GRP at 10(-11)-10(-10) mol/l caused up to fivefold, dose-dependent increases in gastrin secretion; higher doses were less effective and completely desensitized the gastrin cells for the lower doses. After desensitization, vagal stimulation no longer produced gastrin secretion. The substance P antagonist [D-Arg, D-Pro, D-Trp, Leu]-substance P, described as also antagonizing the actions of bombesin, decreased the gastrin response to GRP and abolished the effect of vagal stimulation. The available evidence strongly suggests that GRP nerves are responsible for the stimulatory vagal effects on gastrin secretion in the pig.

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Dumesny, Chelsea, Jane C. Whitley, Graham S. Baldwin, Andrew S. Giraud, and Arthur Shulkes. "Developmental expression and biological activity of gastrin-releasing peptide and its receptors in the kidney." American Journal of Physiology-Renal Physiology 287, no. 3 (September 2004): F578—F585. http://dx.doi.org/10.1152/ajprenal.00416.2003.

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Mammalian gastrin-releasing peptide (GRP) has a widespread distribution and multiple stimulating effects on metabolism, release of regulatory peptides, gastrointestinal and pancreatic secretions, and behavior. GRP is a potent mitogen for a number of tumor types, including colon and lung. Although GRP is known to stimulate the growth of renal tumors, little is known of its synthesis, distribution, and receptors in the developing and mature kidney. Both Northern blot analysis and RT-PCR revealed the presence of GRP mRNA in ovine kidney from midgestation through to adulthood. GRP mRNA was detected in rat kidney from embryonic day 19 to postnatal day 30 by RT-PCR. Sequence-specific radioimmunoassay demonstrated the presence of substantial amounts of fully processed amidated GRP in the ovine renal cortex and medulla. The mRNA for the major receptor subtype, GRP-R, was present in fetal and adult sheep and rat kidneys. The mRNA for the low-affinity GRP receptor, bombesin receptor subtype-3 (BRS-3), was only detected in the rat kidney. In the ovine kidney, immunohistochemistry localized GRP predominantly to the thick ascending limb of the loop of Henle. mRNAs for GRP, GRP-R, and BRS-3 were detected in the human embryonic kidney cell line HEK293, and radioimmunoassay of cell extracts and conditioned media revealed the presence of proGRP but not the amidated form. However, amidated GRP did stimulate the proliferation of these cells. These studies demonstrate that the developing and mature kidney may be previously unidentified sites of autocrine or paracrine action for GRP.

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Kusano, K., H. Gainer, J. F. Battey, Z. Fathi, and E. Wada. "Receptor-activated currents in mouse fibroblasts expressing transfected bombesin receptor subtype cDNAs." American Journal of Physiology-Cell Physiology 265, no. 4 (October 1, 1993): C869—C876. http://dx.doi.org/10.1152/ajpcell.1993.265.4.c869.

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BALB/c 3T3 cells do not normally express receptors for bombesin-like peptides [bombesin (Bn), gastrin-releasing peptide (GRP), and neuromedin B (NmB)]. Transfection of BALB/c 3T3 cells with complementary DNA-encoding GRP receptors or NmB receptors leads to stable expression of functional GRP receptors (GRP Rt) or NmB receptors (NmB Rt), respectively, which are coupled to cell membrane ion channels. Whole cell current analysis using patch electrodes shows that the activation of these newly expressed receptors induces cation conductance increases, most frequently a Ca(2+)-activated plasma membrane K+ conductance. The dose-response (peak-current) relations of both transfected receptor subtypes were sigmoidal and exhibited threshold activation concentration in the picomole range and the saturation of responses to higher concentrations than 10(-8) M. The GRP Rt responded about equally to GRP, NmB, and Bn when compared at equimolar levels, despite their known difference in binding affinity for the three peptides (GRP, Bn > NmB). In contrast, for the NmB Rt, the NmB was more potent than GRP or Bn. Among four GRP/Bn-receptor antagonists tested, the [D-Phe6]Bn(6-13) ethyl ester suppressed GRP Rt responses at low concentrations (10(-7) M). N-acetyl-GRP-(20-26) amide, [Leu13-psi(CH2NH)-Leu14]Bn, and [D-Arg1,D-Phe5,D-Trp7,9,Leu11]substance P also blocked GRP Rt responses but at higher concentrations (10(-5) M). However, at these concentrations, these four antagonists had little effect on NmB Rt responses, thereby showing a specificity of these antagonists for the GRP receptors.

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Qiao, Jingbo, Junquan Liu, Jillian C. Jacobson, Rachael A. Clark, Sora Lee, Li Liu, Zhiqiang An, Ningyan Zhang, and Dai H. Chung. "Anti-GRP-R monoclonal antibody antitumor therapy against neuroblastoma." PLOS ONE 17, no. 12 (December 16, 2022): e0277956. http://dx.doi.org/10.1371/journal.pone.0277956.

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Standard treatment for patients with high-risk neuroblastoma remains multimodal therapy including chemoradiation, surgical resection, and autologous stem cell rescue. Immunotherapy has demonstrated success in treating many types of cancers; however, its use in pediatric solid tumors has been limited by low tumor mutation burdens. Gastrin-releasing peptide receptor (GRP-R) is overexpressed in numerous malignancies, including poorly-differentiated neuroblastoma. Monoclonal antibodies (mAbs) to GRP-R have yet to be developed but could serve as a potential novel immunotherapy. This preclinical study aims to evaluate the efficacy of a novel GRP-R mAb immunotherapy against neuroblastoma. We established four candidate anti-GRP-R mAbs by screening a single-chain variable fragment (scFv) library. GRP-R mAb-1 demonstrated the highest efficacy with the lowest EC50 at 4.607 ng/ml against GRP-R expressing neuroblastoma cells, blocked the GRP-ligand activation of GRP-R and its downstream PI3K/AKT signaling. This resulted in functional inhibition of cell proliferation and anchorage-independent growth, indicating that mAb-1 has an antagonist inhibitory role on GRP-R. To examine the antibody-dependent cellular cytotoxicity (ADCC) of GRP-R mAb-1 on neuroblastoma, we co-cultured neuroblastoma cells with natural killer (NK) cells versus GRP-R mAb-1 treatment alone. GRP-R mAb-1 mediated ADCC effects on neuroblastoma cells and induced release of IFNγ by NK cells under co-culture conditions in vitro. The cytotoxic effects of mAb-1 were confirmed with the secretion of cytotoxic granzyme B from NK cells and the reduction of mitotic tumor cells in vivo using a murine tumor xenograft model. In summary, GRP-R mAb-1 demonstrated efficacious anti-tumor effects on neuroblastoma cells in preclinical models. Importantly, GRP-R mAb-1 may be an efficacious, novel immunotherapy in the treatment of high-risk neuroblastoma patients.

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Ladenheim, EE, LL Hampton, AC Whitney, WO White, JF Battey, and TH Moran. "Disruptions in feeding and body weight control in gastrin-releasing peptide receptor deficient mice." Journal of Endocrinology 174, no. 2 (August 1, 2002): 273–81. http://dx.doi.org/10.1677/joe.0.1740273.

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Bombesin (BN) interacts with two mammalian receptor subtypes termed gastrin-releasing peptide (GRP)-preferring (GRP-R) and neuromedin B (NMB)-preferring (NMB-R) that may mediate the satiety action of BN. We examined the feeding behavior of mice that were deficient in the GRP-R (GRP-R KO) to assess the overall contribution of this receptor subtype in the feeding actions of BN-related peptides. GRP-R KO mice failed to suppress glucose intake in response to systemically administered BN and GRP(18-27), whereas both peptides elicited a potent reduction of intake in wild-type (WT) mice. Neither GRP-R KO nor WT mice suppressed glucose intake following NMB administration. Unlike the impaired responses to BN-like peptides, the feeding inhibitory action of cholecystokinin was enhanced in GRP-R KO mice. Consistent with behavioral results, GRP-R KO mice also exhibited a reduction in c-Fos immunoreactivity in the nucleus of the solitary tract (NTS) and paraventricular nucleus (PVN) following peripheral administration of BN. An evaluation of meal patterns showed that GRP-R KO mice ate significantly more at each meal than WT mice, although total 24 h food consumption was equivalent. A long-term analysis of body weight revealed a significant elevation in GRP-R KO mice compared with WT littermates beginning at 45 weeks of age. These data suggest that the GRP-R mediates the feeding effects of BN-like peptides and participates in the termination of meals in mice.

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Pinski, J., T. Yano, K. Groot, R. Z. Cai, S. Radulovic, and A. V. Schally. "Endocrine effects of new bombesin/gastrin-releasing peptide antagonists in rats." American Journal of Physiology-Endocrinology and Metabolism 263, no. 4 (October 1, 1992): E712—E717. http://dx.doi.org/10.1152/ajpendo.1992.263.4.e712.

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Four new and specific pseudononapeptide bombesin/gastrin-releasing peptide (GRP) receptor antagonists, containing the D-forms of Trp or Trp analogue (Tpi) at position 6, were studied for their effects on the endocrine pancreas and GRP-(14-27)-induced gastrin release in pentobarbital-anesthetized rats. One of the analogues, D-Tpi6,Leu13-psi (CH2NH)Leu14-bombesin-(6-14) (RC-3095), was injected into the lateral brain ventricle just preceding intracerebroventricular administration of GRP-(14-27) to evaluate its antagonistic effect on GRP-induced serum growth hormone (GH) suppression. Analogues RC-3095, D-Trp6,Leu13-psi (CH2NH)Leu14-bombesin-(6-14) (RC-3125), and D-Trp6,Leu13-psi (CH2NH)Phe14-bombesin-(6-14) (RC-3420), but not D-Tpi6,Leu13-psi (CH2NH)Phe14-bombesin-(6-14) (RC-3105), significantly (P < 0.01) inhibited GRP-(14-27)-stimulated serum gastrin secretion. Analogues RC-3095, RC-3420, and RC-3105, but not RC-3125, demonstrated significant (P < 0.05) antagonistic activities on GRP-(14-27)-stimulated plasma glucagon secretion. Intracerebroventricular injection of RC-3095 (10 micrograms) immediately before GRP-(14-27) (1 microgram) completely prevented the GRP-(14-27)-induced serum GH suppression. These results indicate that 1) marked differences exist in the ability of these analogues to antagonize GRP-(14-27)-induced gastrin or glucagon release, suggesting the existence of different bombesin/GRP receptor subtypes, and 2) the central effect of bombesin/GRP on GH release from the pituitary is probably mediated through specific bombesin/GRP receptors.

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Fleischmann, A. M., B. Waser, and J. C. Reubi. "Gastrin-releasing peptide receptors in the tumor vascular bed of various human cancers: high incidence in urinary tract cancers." Journal of Clinical Oncology 27, no. 15_suppl (May 20, 2009): e14575-e14575. http://dx.doi.org/10.1200/jco.2009.27.15_suppl.e14575.

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e14575 Background: Tumoral Gastrin-releasing peptide (GRP) receptors are potential targets for diagnosis and therapy using radiolabeled or cytotoxic GRP analogs. GRP-receptor overexpression has been detected in cancer cells and, more recently, also in the vascular bed of selected tumors. More information on vascular GRP-receptors in cancer is required to asses their potential for vascular targeting applications. Methods: Frequent human cancers from the breast (n=134), lung (n=57), prostate (n=50), kidney (n=32), colon (n=46), urinary tract (n=26) and biliary tract (n=23) were analyzed using in vitro GRP-receptor autoradiography on tissue sections with the 125I-[Tyr4]-bombesin radioligand and/or the universal radioligand 125I-[D-Tyr6, ß-Ala11, Phe13, Nle14]-bombesin(6–14). GRP-receptor expressing tumoral vessels were evaluated in each tumor group for prevalence, quantity (vascular score) and GRP-receptor density. Results: Prevalence of vascular GRP-receptors is variable, ranging from 13% (prostate cancer) to 92% (urinary tract cancer). Different tumor-types within a given site may have divergent prevalence of vascular GRP-receptors (e.g. lung: small cell cancer: 0%; adenocarcinoma: 59%; squamous carcinoma: 83%). Also the vascular score varies widely, with highest score in urinary tract cancer (1.69), moderate scores in lung (0.91), colon (0.88), kidney (0.84) and biliary tract (0.69) cancers and low scores in breast (0.39) and prostate (0.14) cancers. Vascular GRP-receptors are expressed in the muscular vessel wall in moderate to high densities. Normal non- neoplastic control tissues from these organs lack vascular GRP-receptors. Conclusions: Tumoral vessels in all evaluated sites overexpress GRP-receptors, suggesting a major biological function of GRP-receptors in the tumor vascular bed. Vascular GRP-receptor expression varies between the tumor-types indicating tumor-specific mechanisms in their regulation. Urinary tract cancers express vascular GRP-receptors so abundantly, that they are promising candidates for vascular targeting applications. No significant financial relationships to disclose.

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Schjoldager, B., S. S. Poulsen, P. Schmidt, D. H. Coy, and J. J. Holst. "Gastrin-releasing peptide is a transmitter mediating porcine gallbladder contraction." American Journal of Physiology-Gastrointestinal and Liver Physiology 260, no. 4 (April 1, 1991): G577—G585. http://dx.doi.org/10.1152/ajpgi.1991.260.4.g577.

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We studied the role of gastrin-releasing peptide (GRP) for porcine gallbladder motility. Immunohistochemistry visualized nerve fibers containing GRP-like immunoreactivity in muscularis. GRP concentration dependently stimulated contractions of muscularis strips (ED50, 2.9 nM). Neuromedin B was less potent (ED50, 0.1 microM), suggesting existence of GRP-preferring receptors. GRP-induced contractions were unaffected by muscarinic antagonism (1 microM atropine), axonal blockade (1 microM tetrodotoxin), cholecystokinin (CCK) receptor antagonism (10 microM MK-329), or substance P desensitization (1 microM), supporting the existence of myogenic GRP receptors. The bombesin (BN) analogue D-Phe6-BN-(6-13)propylamide (PA) stimulated contractions (ED50, 3.3 nM) with low efficacy (29% of that of GRP). D-Phe6-BN-(6-13)PA (1 microM) shifted GRP concentration-response curves one log to the right. D-Phe6-BN-(6-13)PA interacted specifically with GRP receptors; while abolishing responses to GRP (1 nM), responses to substance P (0.1 microM) and CCK-8 (1 nM) were unchanged. Electrical stimulation (10 Hz, 0.5 ms, 10 V) caused a rapid onset-slow offset, tetrodotoxin-sensitive excitation. Atropine reduced the amplitude to 58% and caused a delayed, slow onset-slow decline response. D-Phe6-BN-(6-13)PA reduced the amplitude to 59% and caused a very rapid onset-rapid decline response. Atropine plus D-Phe6-BN-(6-13)PA abolished responses to nerve stimulation. Nerve stimulation caused significant release of GRP-like immunoreactivity. Thus two neural inputs were defined: a cholinergic rapid onset-rapid offset excitation and a delayed, slow onset-slow offset excitation caused by release and subsequent binding of GRP to GRP-preferring receptors.

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Lenz, H. J. "CNS regulation of gastric and autonomic functions in dogs by gastrin-releasing peptide." American Journal of Physiology-Gastrointestinal and Liver Physiology 255, no. 3 (September 1, 1988): G298—G303. http://dx.doi.org/10.1152/ajpgi.1988.255.3.g298.

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The central nervous system effects of canine gastrin-releasing peptide (GRP) were studied on gastric acid secretion, emptying, blood flow, and the autonomic nervous system in conscious dogs. GRP injected into the third cerebral ventricle significantly (P less than 0.01) increased plasma epinephrine but not norepinephrine concentrations. GRP (0.1-1.0 nmol/kg) significantly decreased gastric acid secretion stimulated by an 8% peptone meal, delayed gastric emptying of the liquid peptone meal, and increased left gastric artery flow. Ganglionic blockade, truncal vagotomy, or adrenalectomy did not abolish the inhibitory effect of GRP on gastric acid secretion. However, ganglionic blockade or vagotomy abolished the GRP-induced inhibition of gastric emptying, and ganglionic blockade or adrenalectomy abolished the GRP-induced increases in left gastric artery flow and plasma epinephrine concentrations. An intravenous infusion of epinephrine that produced similar plasma concentrations of epinephrine that were observed after cerebroventricular injection of GRP mimicked the increase in left gastric artery flow induced by GRP. It is concluded that 1) GRP acts within the central nervous system to activate the sympathoadrenal axis, 2) GRP inhibits gastric emptying of a liquid meal by a vagally dependent mechanism and enhances left gastric artery flow by the release of epinephrine from the adrenal medulla, and 3) the pathway(s) that mediate the GRP-induced inhibition of gastric acid in the dog remain unknown.

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Kim, Mi-Kyoung, Hyun-Joo Park, Yeon Kim, Soo-Kyung Bae, Hyung Kim, and Moon-Kyoung Bae. "Involvement of Gastrin-Releasing Peptide Receptor in the Regulation of Adipocyte Differentiation in 3T3-L1 Cells." International Journal of Molecular Sciences 19, no. 12 (December 10, 2018): 3971. http://dx.doi.org/10.3390/ijms19123971.

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Gastrin-releasing peptide (GRP), a member of bombesin-like peptides, and its receptor (GRP-R) play an important role in various physiological and pathological conditions. In this work, we investigated the role of GRP-R on adipogenesis in 3T3-L1 adipocytes. The expression of GRP-R was significantly increased during the adipocyte differentiation of 3T3-L1 cells. The inhibition of GRP-R by the antagonist RC-3095 affected adipogenesis in 3T3-L1 cells, which reduced lipid accumulation and regulated the expression of adipogenic genes. Moreover, cyclic AMP response element-binding protein (CREB) directly bound to the GRP-R promoter upon exposure to adipogenic stimuli. The down-regulation of GRP-R by the knockdown of CREB inhibited adipocyte differentiation of 3T3-L1 cells. Together these results suggest that the regulation of GRP-R activity or expression has an influence on adipogenesis through regulating adipogenic related genes.

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Kawai, Koichi, Yukinobu Chiba, Hidehito Mukai, Eisuke Munekata, and Kamejiro Yamashita. "Effects of neuromedin B, gastrin-releasing peptide-10 and their fragment peptides on secretion of gastrointestinal and pancreatic hormones in dogs." Acta Endocrinologica 117, no. 2 (February 1988): 205–13. http://dx.doi.org/10.1530/acta.0.1170205.

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Abstract. The effects of neuromedin B (NMB), gastrin-releasing peptide (GRP)-10 and their C-terminal fragment peptides on the pancreatic and gastrointestinal hormone release were studied in dogs. Intravenous bolus injections of NMB and GRP-10 (4.5 nmol/kg) into conscious dogs elicited a sharp and statistically significant rise in plasma gastrin and insulin levels, but only GRP-10 brought on a significant rise in the plasma glucagon and enteroglucagon levels. The degree of stimulation of gastrin and insulin secretion by NMB and GRP-10 was dose-dependent. With a dose of 4.5 nmol/kg, the minimum size of C-terminal fragment peptides of NMB and GRP-10 to stimulate gastrin secretion was NMB (2–10) and GRP-10 (3–10), respectively. Both NMB and GRP-10 (0.1-100 nmol/l) stimulated insulin release from the isolated canine pancreas. The glucagon release was stimulated by 10 and 100 nmol/l GRP-10 and was not stimulated by the same doses of NMB. The somatostatin release was not influenced by either peptide. It is concluded that 1) NMB and GRP-10 can stimulate gastrin and pancreatic hormone secretion, and the latter effect may be mainly due to a direct action on the islet cells; 2) the stimulatory effect of GRP-10 is stronger than that of NMB. The difference in the minimal active fragment between NMB and GRP-10 suggests that the amino acid of position 3 – NMB (Leu) and GRP-10 (His) – may play an important role in their biological activity.

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Whitley, JC, A. Shulkes, LA Salamonsen, D. Vogiagis, M. Familari, and AS Giraud. "Temporal expression and cellular localization of a gastrin-releasing peptide-related gene in ovine uterus during the oestrous cycle and pregnancy." Journal of Endocrinology 157, no. 1 (April 1, 1998): 139–48. http://dx.doi.org/10.1677/joe.0.1570139.

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Synthesis of both mRNA and peptide for gastrin-releasing peptide (GRP) has been demonstrated in the pregnant endometrium of sheep and women. However, it is not known whether GRP is synthesized in the sheep uterus during the oestrous cycle. Furthermore the cellular site of GRP mRNA synthesis in the uterus has not been determined. Therefore we examined the synthesis of GRP and determined the cellular location of GRP peptide and mRNA in sheep uterus taken at different times during the oestrous cycle (duration 17 days) and pregnancy (duration 145 days). Northern blot analysis of RNA isolated from ovine endometrium revealed low or no GRP mRNA at days 4, 10, 12 and 14 of the oestrous cycle and a 24-fold rise in GRP mRNA (normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA) between days 14 and 16. A similar pattern was observed during early pregnancy, with a 12-fold rise in GRP mRNA:GAPDH mRNA between days 17 and 20 of pregnancy. Levels of GRP peptide were determined by RIA and found to be low in endometrium isolated at days 4, 10, 12 and 14 of the oestrous cycle (1.0-1.6 pmol/g) and 4 to 5-fold higher at day 16. In situ hybridization localized GRP synthesis to the epithelial cells of the uterine glands at day 16 of the oestrous cycle and at days 17, 20, 40 and 50 of pregnancy. At day 140 of pregnancy diffuse hybridization to cells of the myometrium was also observed. Immunohistochemistry localized GRP peptide to the apical cytoplasm of uterine glandular epithelial cells at day 16 of the oestrous cycle. For samples obtained at day 20 of pregnancy, the area surrounding the glands also showed moderately strong staining. Further staining in the glandular lumen and the stromal tissue surrounding the glands was apparent at day 140 of pregnancy. No GRP immunoreactivity could be detected in the peripheral plasma during the oestrous cycle or the first 20 days of pregnancy. Sizing chromatography of GRP immunoreactivity extracted from endometrial tissue taken at day 10 of the oestrous cycle revealed two peaks that co-eluted with GRP(1-27) and GRP(18-27). However, during luteolysis and oestrus the major peak of GRP immunoreactivity extracted from endometrial tissue was larger than GRP(1-27) and similar to that seen previously in the gravid ovine endometrium. These studies demonstrate that a peptide similar to, but larger than, GRP is a major product of the glandular epithelium of the ovine uterus during the luteal regression phase of the oestrous cycle and post-blastocyst implantation in pregnancy and provide further evidence that GRP-related peptides have important regulatory roles in uterine function.

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46

Wang, Chang-rui, Kun-kun Deng, and Yan Bai. "Microstructure, and Mechanical and Wear Properties of Grp/AZ91 Magnesium Matrix Composites." Materials 12, no. 7 (April 11, 2019): 1190. http://dx.doi.org/10.3390/ma12071190.

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Based on semi-solid mixing technology, two kinds of as-cast Grp (Graphite particles)/AZ91 composites with different Grp volume fractions (5 vol %, 10 vol %) were prepared; these are called 5 vol % Grp/AZ91 composites and 10 vol % Grp/AZ91 composites, respectively. In order to eliminate casting defects, refine grains, and improve mechanical properties, thermal deformation analysis of these composites was conducted. The effect of the addition of Grp and thermal deformation on the microstructure, mechanical properties, and wear resistance of AZ91 composite was explored. The results showed that after 5 vol % Grp was added into the as-cast AZ91 alloy, Mg17Al12 phases were no longer precipitated reticularly along the grain boundary, and Al4C3 phases were formed inside the composite. With the increase in the volume fraction of Grp, the grains of the AZ91 composites were steadily refined. With the increase of forging pass, the grain size of 5% Grp/AZ91 composites decreased first, and then increased. Additionally, the Grp size decreased gradually. There was little change in the yield strength, and the tensile strength and elongation were improved to a certain extent. After forging and extrusion of 5% Grp/AZ91 composites once, the grain size and Grp size were further reduced, and the yield strength, tensile strength, and elongation were increased by 23%, 30%, and 65%, respectively, compared with the composite after forging. With the increase of the number of forging passes before extrusion, the grain size decreased little by little, while the Grp size remained unchanged. The average yield strength, tensile strength, and elongation of the composites after forging and extrusion six times were increased by 3%, 3%, and 23%, respectively, compared with the composite after forging and extrusion once. The wear rate and friction coefficient of the 5% Grp/AZ91 composites decreased after forging once, and the wear mechanism was mainly due to ploughing wear. By comparison, the wear rate and friction coefficient of the 5% Grp/AZ91 composites increased in the extrusion state, and the main wear mechanism was from wedge formation and micro-cutting wear.

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47

Fleischmann, Achim, Beatrice Waser, and Jean Claude Reubi. "Overexpression of Gastrin-Releasing Peptide Receptors in Tumor-Associated Blood Vessels of Human Ovarian Neoplasms." Analytical Cellular Pathology 29, no. 5 (January 1, 2007): 421–33. http://dx.doi.org/10.1155/2007/798790.

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Background: Peptide receptors, overexpressed in specific cancers, represent new diagnostic and therapeutic targets. In this study, receptors for the gastrin-releasing peptide (GRP), and other members of the bombesin-family of peptides, were evaluated in ovarian neoplasms. Methods: 75 primary, secondary and metastatic ovarian tumors were investigated for their bombesin-receptor subtype expression, incidence, localization and density using in vitro autoradiography on tissue sections with the universal radioligand 125I-[D-Tyr6, ß-Ala11, Phe13, Nle14]-bombesin(6-14) and the GRP-receptor subtype-preferring 125I-[Tyr4]-bombesin. Results: GRP-receptors were detected in 42/61 primary ovarian tumors; other bombesin-receptor subtypes (BB1, bb3) were rarely present (3/61). Two different tissue compartments expressed GRP-receptors: the tumoral vasculature was the predominant site of GRP-receptor expression (38/61), whereas neoplastic cells more rarely expressed GRP-receptors (14/61). GRP-receptor positive vessels were present in the various classes of ovarian tumors; generally, malignant tumors had a higher incidence of GRP-receptor positive vessels compared to their benign counterparts. The prevalence of such vessels was particularly high in ovarian carcinomas (16/19) and their metastases (5/5). The GRP-receptors were expressed in high density in the muscular vessel wall. Normal ovary (n=10) lacked GRP-receptors. Conclusions: The large amounts of GRP-receptors in ovarian tumor vessels suggest a role in tumoral vasculature and possibly angiogenesis. Further, these vessels might be targeted in vivo with bombesin analogs for diagnosis or for therapy.

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48

Takehara, Y., K. Sumii, A. Tari, M. Yoshihara, M. Sumii, K. Haruma, G. Kajiyama, S. V. Wu, and J. H. Walsh. "Evidence that endogenous GRP in rat stomach mediates omeprazole-induced hypergastrinemia." American Journal of Physiology-Gastrointestinal and Liver Physiology 271, no. 5 (November 1, 1996): G799—G804. http://dx.doi.org/10.1152/ajpgi.1996.271.5.g799.

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To investigate the physiological role of endogenous gastrin-releasing peptide (GRP) in regulating the release of gastrin, we evaluated the response of intragastric pH, gastrin, and GRP after omeprazole treatment in rats. A significant elevation of the plasma level of GRP (P< 0.01) and a significant reduction of the antral content of GRP (P <0.05) were observed after the administration of 100 mg/kg omeprazole. The antral content of GRP was significantly decreased 12 h after omeprazole administration and thereafter gradually returned to control levels. Peak values for intragastric pH and plasma GRP were observed 3 h after omeprazole administration and before the peak of serum gastrin. The bombesin antagonist [D-Phe6]-bombesin-(6,13)-methyl ester significantly inhibited gastrin release after omeprazole treatment (P < 0.05). These observations indicate that omeprazole-induced inhibition of acid secretion stimulates the release of GRP and suggest that the secretion of GRP induced by omeprazole may stimulate the secretion of gastrin, at least in the early phase.

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49

Mayer, E. A., J. R. Reeve, S. Khawaja, P. Chew, J. Elashoff, B. Clark, and J. H. Walsh. "Potency of natural and synthetic canine gastrin-releasing decapeptide on canine antral muscle." American Journal of Physiology-Gastrointestinal and Liver Physiology 250, no. 5 (May 1, 1986): G581—G587. http://dx.doi.org/10.1152/ajpgi.1986.250.5.g581.

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The carboxyl terminal decapeptide of gastrin-releasing peptide (GRP-10), a small, naturally occurring bombesin-like peptide, has been isolated from canine antral muscle, synthesized, and its bioactivity compared with other synthetic and natural gastrin-releasing peptides on stimulation of spontaneously occurring contractions of canine circular antral muscle in vitro. Concentrations of peptides were verified by amino acid analysis and radioimmunoassay. In this system three forms of natural canine GRP, synthetic GRP-10, synthetic porcine gastrin-releasing heptacosapeptide (GRP-27), [Gln3]GRP-10, and [Arg3]GRP-10 all were similar in potency to synthetic amphibian bombesin. These results differ from the low activity of GRP-10 previously reported in rat brain. The full biological potency on canine antral motility and the presence of GRP-10 in nerve fibers in the gut and in the spinal cord suggest a possible role for this peptide as a neurotransmitter or neuromodulator in regulation of smooth muscle contraction.

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Gao, Xin, Kejian Geng, Cuicui Sun, Suqing Zhang, Jixue Zhou, Jianhua Wu, Xinfang Zhang, and Xitao Wang. "Effects of Graphite Particle Content and Holding Time on the Microstructure and Mechanical Properties of the Graphite/AZ91D Composite." Metals 13, no. 1 (December 25, 2022): 57. http://dx.doi.org/10.3390/met13010057.

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The effects of Grp (graphite particles) addition and holding time on the microstructure and mechanical properties of the Grp/AZ91D composite were investigated in this work. The results indicated that the distribution of Grp in the matrix was determined by the self-stabilizing mechanism and relationships between the solidifying interface and the particles. Due to the self-stabilizing mechanism, a small amount of Grp would uniformly distribute in the melt alloy, and as the amount of Grp increased, agglomeration would occur. Accordingly, the former would be engulfed by the solidifying interface and the latter would be pushed. With an increased holding time, Grp tended to agglomerate, due to the interfacial reaction that occurred, and as a result, the solidifying interface will push it. The Grp/AZ91D composite with the addition of 1.5 wt.% Grp and a holding time of 15 min obtained grains 30.2 μm in size with a hardness of 89.07 HV, which was a decrease of 83.04% and increase of 35.06% compared to AZ91D, respectively.

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Journal articles on the topic 'GRP'

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