title: The GABA/benzodiazepine receptor complex in the central amygdalar nucleus and stress ulcers in rats.
abstract: The effects of bilateral microinjections of chlordiazepoxide and GABA into the central amygdalar nucleus on gastric ulcer formation induced by cold-restraint were examined in chronically implanted Wistar rats. Higher doses of chlordiazepoxide (20 and 30 micrograms/amygdala) significantly reduced stress ulcer development, whereas a lower dose (2.5 micrograms) produced a nonsignificant increase in ulcer severity. A similar dose/response pattern was observed following GABA administration. The benzodiazepine receptor antagonist Ro15-1788, applied to the amygdala, abolished the protective effects of both chlordiazepoxide and GABA. In addition, when Ro15-1788 (10 micrograms) was injected into the amygdala by itself, it aggravated the gastric stress pathology. However, a lower dose (5 micrograms) had an attenuating effect, opposite to the pattern of effects produced by chlordiazepoxide and GABA. The role of the amygdalar GABA-benzodiazepine receptor complex in stressful conditions is discussed.
authors.affiliation: St. Francis Xavier University, Antigonish, Nova Scotia, Canada.
authors.forename: R M
authors.initials: RM
authors.lastname: Sullivan
authors.forename: P G
authors.initials: PG
authors.lastname: Henke
authors.forename: A
authors.initials: A
authors.lastname: Ray
authors.forename: M A
authors.initials: MA
authors.lastname: Hebert
authors.forename: J M
authors.initials: JM
authors.lastname: Trimper
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000503:physiopathology*; D000818:Animals; D001143:Arousal / Q000502:physiology*; D002707:Chlordiazepoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005442:Flumazenil / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D013276:Stomach Ulcer / Q000503:physiopathology*; D013315:Stress, Psychological / Q000150:complications*
chemical_list: D011963:Receptors, GABA-A; D005442:Flumazenil; D002707:Chlordiazepoxide