title: Noradrenergic mechanisms in the central amygdalar nucleus and gastric stress ulcer formation in rats.
abstract: Microinjections of noradrenaline (NA, 0.3, 3.0 and 30.0 micrograms) into the central amygdalar nucleus (CEA) produced dose-related attenuations of cold restraint (3 h at 4 degrees C) induced gastric ulcer formation in rats. On the other hand, stress ulcer aggravating effects were seen with beta-adrenoceptor antagonist, propranolol (10 micrograms) but not with the alpha-adrenoceptor antagonist, prazosin (1 and 10 micrograms). Moderate enhancements of gastric stress lesions were also seen with the NA release inhibitor clonidine (1 microgram) and the neurotoxin DSP-4 (25 micrograms). Further, pretreatment of rats with intra-amygdalar (i.am.) propranolol but not prazosin, antagonized and reversed the gastric cytoprotective effects of NA. The results indicate that beta-adrenoceptor-mediated NAergic mechanisms at the level of the CEA are important for the maintenance of gastric mucosal integrity during immobilization stress.
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: D000320:Adrenergic Fibers / Q000187:drug effects / Q000502:physiology*; D000679:Amygdala / Q000187:drug effects / Q000503:physiopathology*; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009638:Norepinephrine / Q000494:pharmacology / Q000502:physiology*; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012149:Restraint, Physical; D013276:Stomach Ulcer / Q000209:etiology / Q000503:physiopathology*; D013315:Stress, Psychological / Q000150:complications / Q000503:physiopathology*
chemical_list: D003000:Clonidine; D009638:Norepinephrine; D011224:Prazosin