Peripheral and central cholecystokinin receptors regulate postprandial intestinal motility in the rat.
Postprandial cholecystokinin (CCK) has been suggested as an important mediator of disruption of migrating myoelectric complexes (MMC) after a meal. However, the role of CCK in regulating small intestinal motility in rats and the participation of central and/or peripheral CCK-A and B receptors in CCK actions, are still unclear. For this study, Sprague-Dawley rats were prepared with electrodes in the small intestine, a catheter in the jugular vein and an intracerebroventricular (i.c.v.) cannula. Postprandial disruption of the MMC was blocked by the i.v. infusion of the CCK-B antagonist L-365,260 (2 x 10(-7) mol/kg), but not by the infusion of the CCK-A antagonist L-364,718. When administered i.c.v., L-364,718 (2.25 x 10(-9) mol), but not L-365,260, restored the MMC pattern. The i.v. infusion of CCK-8 (1-3 x 10(-9) mol/kg) or CCK-4 (10(-7) mol/kg) disrupted the MMC pattern. CCK-8 effects where prevented by the i.v. infusion of either L-364,718 or L-365,260. Administered i.c.v., only the antagonist L-364,718 prevented CCK-8 disruption of the MMC. These results suggest that CCK-mediated motor changes after a meal are due to stimulation of peripheral CCK-B receptors. CCK also induces a release of central CCK that through CCK-A receptors participates on MMC disruption.
Rodríguez-Membrilla
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A
Department of Cell Biology and Physiology, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Martínez
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V
Vergara
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P
D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D002490:Central Nervous System / Q000502:physiology / Q000648:ultrastructure*; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology; D020109:Devazepide; D004435:Eating; D004594:Electrophysiology; D005769:Gastrointestinal Motility / Q000502:physiology*; D007421:Intestine, Small / Q000502:physiology; D008297:Male; D016065:Myoelectric Complex, Migrating / Q000502:physiology; D017933:Peripheral Nervous System / Q000502:physiology / Q000648:ultrastructure*; D010671:Phenylurea Compounds; D051381:Rats; D017207:Rats, Sprague-Dawley; D011949:Receptors, Cholecystokinin / Q000502:physiology*; D012844:Sincalide / Q000037:antagonists & inhibitors / Q000494:pharmacology
D001570:Benzodiazepinones; D010671:Phenylurea Compounds; D011949:Receptors, Cholecystokinin; C058121:L 365260; D002766:Cholecystokinin; D020109:Devazepide; D012844:Sincalide