Enhancement of colonic motor response to feeding by central endogenous opiates in the dog.
The role of endogenous opiates in the colonic motor response to feeding has been investigated in four dogs chronically fitted with two strain gages on the proximal and distal colon and a cannula in cerebral lateral ventricle. A daily meal stimulated the colonic motility during 8-10 hrs. The colonic motility index was significantly higher during this period when an enkephalinase inhibitor, tiorphan, was intracerebroventricularly (i.c.v.) administered at a dose of 0.1 mg/kg before the meal. This effect was blocked by a previous i.c.v. administration of naltrexone (0.1 mg/kg) and reproduced by (D-Ala2, Met5) enkephalinamide (DALAMIDE) at a dose of 50 mg/kg. I.c.v. administration of tiorphan or DALAMIDE did not modify the colonic motility in dogs fasted for 48 hrs. The postprandial motility index remained unchanged after intravenous administration of tiorphan or DALAMIDE at the same dosages. These results provide evidence for a central control of the colonic motor response to feeding by endogenous enkephalins in dogs.
D000818:Animals; D003106:Colon / Q000187:drug effects* / Q000502:physiology; D004285:Dogs; D004435:Eating; D004723:Endorphins / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000502:physiology; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D051379:Mice; D009271:Naltrexone / Q000494:pharmacology; D015260:Neprilysin; D011480:Protease Inhibitors; D015244:Thiorphan; D008625:Tiopronin / Q000031:analogs & derivatives / Q000494:pharmacology
D004723:Endorphins; D011480:Protease Inhibitors; D004744:Enkephalin, Methionine; D009271:Naltrexone; C022118:enkephalinamide-Met, Ala(2)-; D015244:Thiorphan; D008625:Tiopronin; D015260:Neprilysin