Role of dopaminergic mechanisms in the central amygdalar nucleus in the regulation of stress-induced gastric ulcer formation in rats.
Microinjections (i/am) of dopamine (DA) antagonists, haloperidol or clozapine (1 and 5 micrograms) into the central amygdalar nucleus (CEA) produced dose-related aggravations in cold-restraint (3 h at 4 degrees C) stress-induced gastric ulcer formation in rats. On the other hand, DA (10 micrograms, i/am), its agonist, apomorphine (5 mg/kg, ip) and its precursor, l-Dopa (100 mg/kg, ip) significantly inhibited stress ulcerogenesis. Pretreatment of rats (i/am) with clozapine antagonized or reversed the gastric cytoprotective effects of DA, apomorphine and l-Dopa. The results indicate that the CEA is important for the observed gastric cytomodulatory effects of both centrally and peripherally administered dopaminergic agents during stressful experiences.
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D000679:Amygdala / Q000187:drug effects*; D000818:Animals; D003024:Clozapine / Q000494:pharmacology*; D003984:Dibenzazepines / Q000494:pharmacology*; D018492:Dopamine Antagonists; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D010437:Peptic Ulcer / Q000209:etiology* / Q000517:prevention & control; D051381:Rats; D011919:Rats, Inbred Strains; D013312:Stress, Physiological / Q000150:complications*
D003984:Dibenzazepines; D018492:Dopamine Antagonists; D003024:Clozapine; D006220:Haloperidol