title: Opiate mechanisms in the central amygdala and gastric stress pathology in rats.
abstract: Bilateral microinjections of the opiate antagonist naloxone (0.1, 1.0 and 10.0 micrograms) into the central nucleus of the amygdala (CEA) produced a significant potentiation of cold restraint-induced gastric pathology in rats. The opiate agonist, beta-endorphin (0.1, 1.0 and 10.0 micrograms), on the other hand, inhibited stress ulcer formation in a dose-related manner. Stress ulcer-attenuating effects were also seen with intra-CEA injections of the enkephalin analogs [D-Ala2,D-Leu5]enkephalin (10.0 micrograms) and [D-Ala2]Met-enkephalinamide (10.0 micrograms). Pretreatment of rats with naloxone (1.0 microgram) completely antagonized and even reversed the gastric cytoprotective effects of beta-endorphin (1.0 and 10.0 micrograms). The results indicate that the CEA is important in the gastric cytomodulatory effects of endogenous opiates during stressful experiences.
authors.affiliation: Department of Psychology, St. Francis Xavier University, Antigonish, N.S., Canada.
authors.forename: A
authors.initials: A
authors.lastname: Ray
authors.forename: P G
authors.initials: PG
authors.lastname: Henke
authors.forename: R M
authors.initials: RM
authors.lastname: Sullivan
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000503:physiopathology*; D000818:Animals; D004723:Endorphins / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology*; D012149:Restraint, Physical; D013276:Stomach Ulcer / Q000523:psychology*; D013312:Stress, Physiological / Q000503:physiopathology*
chemical_list: D004723:Endorphins; D011957:Receptors, Opioid; D009270:Naloxone; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; C022118:enkephalinamide-Met, Ala(2)-; D016308:Enkephalin, Leucine-2-Alanine