title: Intestinal transit of fat depends on accelerating effect of cholecystokinin and slowing effect of an opioid pathway.
abstract: Fat has been described to both accelerate and slow intestinal transit. We hypothesized that the fat-induced jejunal brake depends on the combined accelerating effect of CCK and the slowing effect of an opioid pathway. Using a multifistulated model, intestinal transit was measured in four dogs, while 60 mM oleate was delivered into the proximal gut with either 0 or 6 mg naloxone, and 0.1 mg/kg devazepide (a peripheral CCK-A-receptor antagonist) administered intraluminally and intravenously, respectively. In a second study, intestinal transit was measured in seven dogs, while naloxone was delivered intraluminally at 0-, 3-, 6-, or 12-mg doses. Compared to the jejunal brake (marker recovery of 50.1 +/- 2.6%), intestinal transit was slowed by the CCK-A antagonist (36.4 +/- 8.3%; P < 0.05) and accelerated by naloxone (82.0 +/- 6.8%; P < 0.05). The accelerating effect of CCK occurred early in the transit response, while the dose-dependent effect (P < 0.05) of naloxone occurred later. We conclude that fat-induced jejunal brake depends on the early accelerating effect of CCK and the later slowing effect of a naloxone-sensitive opioid pathway.
authors.affiliation: Department of Medicine, Cedars-Sinai Medical Center, CSMC Burns & Allen Research Institute, Los Angeles, California 90048, USA.
authors.forename: Henry C
authors.initials: HC
authors.lastname: Lin
authors.forename: Oren
authors.initials: O
authors.lastname: Zaidel
authors.forename: Susan
authors.initials: S
authors.lastname: Hum
mesh_terms: D000818:Animals; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000502:physiology*; D020109:Devazepide / Q000494:pharmacology; D004041:Dietary Fats / Q000378:metabolism*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005772:Gastrointestinal Transit / Q000187:drug effects / Q000502:physiology*; D007583:Jejunum / Q000187:drug effects / Q000502:physiology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D019301:Oleic Acid / Q000378:metabolism; D043886:Receptor, Cholecystokinin A; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors / Q000502:physiology; D011957:Receptors, Opioid / Q000502:physiology*
chemical_list: D004041:Dietary Fats; D009292:Narcotic Antagonists; D043886:Receptor, Cholecystokinin A; D011949:Receptors, Cholecystokinin; D011957:Receptors, Opioid; D019301:Oleic Acid; D009270:Naloxone; D002766:Cholecystokinin; D020109:Devazepide