Effects of atropine on pancreatic response to bethanechol, cholecystokinin, and food intake in rats
| Autor: | M. F. O'Rourke, R. D. Reidelberger, T. E. Solomon |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Atropine
Male Agonist medicine.medical_specialty Physiology medicine.drug_class Bethanechol Cholecystokinin receptor Sincalide Eating Bethanechol Compounds Physiology (medical) Internal medicine medicine Animals Amylase Pancreas Cholecystokinin Dose-Response Relationship Drug Hepatology biology digestive oral and skin physiology Gastroenterology Antagonist Rats Inbred Strains Rats Endocrinology Competitive antagonist biology.protein medicine.drug |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 261:G735-G741 |
| ISSN: | 1522-1547 0193-1857 |
| DOI: | 10.1152/ajpgi.1991.261.5.g735 |
| Popis: | Atropine was used to examine the role of cholinergic mechanisms in the pancreatic secretory response to food intake. Unanesthetized rats with gastric, jugular vein, bile-pancreatic, and duodenal cannulas were used; bile-pancreatic juice was recirculated. The maximal response to bethanechol (4 mg.kg-1.h-1) was similar to cholecystokinin (CCK)-8-induced maximal secretion. Atropine (25-200 micrograms.kg-1.h-1) markedly inhibited basal amylase output and caused dose-related inhibition of the incremental response to a maximal dose of bethanechol. Atropine (50 micrograms.kg-1.h-1) shifted the dose-response curve to bethanechol (1-32 mg.kg-1.h-1) to the right but did not alter maximal amylase output. L 364718 (0.5 mg/kg), a CCK receptor antagonist, had no effect on bethanechol-stimulated pancreatic secretion. Atropine (50 micrograms.kg-1.h-1) did not affect the incremental responses to low doses of CCK-8; the maximal response occurred at a higher CCK-8 dose because atropine decreased basal secretion. Atropine (50 or 200 micrograms.kg-1.h-1) did not decrease the amylase response to ingestion of a liquid meal. We conclude that 1) bethanechol is a full agonist for stimulation of pancreatic enzyme secretion and its effects are not mediated by CCK release; 2) atropine is a competitive antagonist of bethanechol-induced pancreatic secretion in vivo but does not directly affect responses to CCK-8; 3) cholinergic mechanisms do not mediate the pancreatic enzyme response to a liquid meal in rats. |
| Databáze: | OpenAIRE |
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