It is our belief that digestion processes are brought about by the interactions between substances produced by the GI tract, pancreas and possibly the brain and that the role of a single peptide is downplayed by these interactions. The objective of this proposal is to investigate the crossreactivity and interactivity of these peptides. We plan to study by radioimmunoassay and by bioassay the chemical nature, biologic action, storage and release of CCK-like peptide found in brain and GI tract of several experimental animals. We will study the interrelationships between pancreatic endocrine and exocrine functions and the release and actions of GI and pancreatic hormones. We plan to study, continuously, the release and interactions of gastrointestinal and pancreatic hormones in animals in physiologic conditions over expanded periods of time. We plan to study the interrelationships between the release and biologic actions of GI and pancreatic hormones after neutralization of peptides with specific antibodies directed towards regions or towards all of the peptide molecule. We will study the effect of cigarette smoke and of chemical agents that are found in cigarette smoke on the release and actions of GI peptides and pancreatic endocrine and exocrine functions. We will conduct studies designed to generate specific antibodies by using the monoclonal antibody technique. These antibodies will be used to study the actions of GI peptides and to develop region specific radioimmunoassays. We will investigate the role of acute and chronic exogenous and endogenous cholecystokinin on satiety and sbusequent weight loss in rats and dogs. We will study the interrelations between hormones of gastrointestinal, pancreatic, pituitary and gonadal origin in experiments designed to determine if there is a centralized mechanism that controls the release and actions of gastrointestinal hormones. We plan to establish radioligand binding assays in order to identify cholecystokinin and pancreatic polypeptide receptors in target tissues of these peptides in several species of animals. We will conduct studies to optimize our existing radioimmunoassays and to develop and validate newer systems for peptides that are currently not measured in our laboratory.

Project Start
1982-02-01
Project End
1987-01-31
Budget Start
1985-02-01
Budget End
1986-01-31
Support Year
4
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Arkansas for Medical Sciences
Department
Type
Schools of Medicine
DUNS #
City
Little Rock
State
AR
Country
United States
Zip Code
72205
Rayford, P L; Inoue, K; Chowdhury, P et al. (1991) Tissue and plasma levels of immunoreactive gastrin and cholecystokinin in chickens with and without bombesin. J Assoc Acad Minor Phys 2:67-71
Chowdhury, P; Hosotani, R; Chang, L et al. (1990) Metabolic and pathologic effects of nicotine on gastrointestinal tract and pancreas of rats. Pancreas 5:222-9
Hosotani, R; Inoue, K; Kogire, M et al. (1989) Effect of natural peptide YY on pancreatic secretion and cholecystokinin release in conscious dogs. Dig Dis Sci 34:468-73
Hosotani, R; Chowdhury, P; McKay, D et al. (1989) Mechanism of action of nicotine on amylase release by isolated pancreatic acini. Pharmacol Biochem Behav 33:663-6
Hosotani, R; Chowdhury, P; Rayford, P L (1989) L-364,718, a new CCK antagonist, inhibits postprandial pancreatic secretion and PP release in dogs. Dig Dis Sci 34:462-7
Inoue, K; Chowdhury, P; Hosotani, R et al. (1989) Total small bowel resection inhibited bombesin-stimulated release of cholecystokinin and pancreatic polypeptide in anesthetized cats. J Surg Res 47:87-91
Hosotani, R; Chowdhury, P; Huang, Y S et al. (1989) Effect of L-364,718 on GRP-stimulated pancreatic and gastric secretions and GI peptides in conscious dogs. Pancreas 4:550-5
Hosotani, R; Chowdhury, P; McKay, D et al. (1988) Effect of L364718, a new CCK antagonist, on amylase secretion in isolated rat pancreatic acini. Pancreas 3:95-8
Hosotani, R; Inoue, K; Kogire, M et al. (1987) Synthetic neuromedin C stimulates exocrine pancreatic secretion in dogs and rats. Pancreas 2:414-21
Hosotani, R; Chowdhury, P; McKay, D et al. (1987) L364718, a new CCK antagonist, inhibits biological actions of CCK in conscious dogs. Peptides 8:1061-4

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