A differential dopamine receptor involvement during stress ulcer formation in rats.
The involvement of dopaminergic (DA) receptors and their possible interactions were evaluated during stress ulcer formation in rats. The DA1 antagonist SCH 23390 (0.025, 0.05, or 0.1 mg/kg) produced only marginal aggravations in gastric stress pathology when compared to vehicle controls. The DA2 antagonist sulpiride (10 or 50 mg/kg) had dose-related effects. The lower dose aggravated whereas the higher dose attenuated stress ulcerogenesis. The DA2 agonist bromocriptine (2.5 or 5.0 mg/kg), however, attenuated gastric stress ulcers. Pretreatment of rats with the DA depletor alpha-methyl-para-tyrosine or the DA1-antagonist SCH23390 clearly neutralized the stress ulcer-attenuating effects of bromocriptine. These results reaffirm a gastric cytoprotective role for DA and further suggest that DA1-DA2 receptor interactions are crucial during DAergic regulation of gastric mucosal integrity during stress.
Puri
S
S
Department of Pharmacology, University College of Medical Sciences, Shahdara, Delhi, India.
Ray
A
A
Chakravarti
A K
AK
Sen
P A
PA
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D005753:Gastric Mucosa / Q000473:pathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000187:drug effects; D017448:Receptors, Dopamine D2 / Q000187:drug effects; D013276:Stomach Ulcer / Q000473:pathology / Q000503:physiopathology*; D013315:Stress, Psychological / Q000473:pathology*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D015259:Dopamine Agents; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D001971:Bromocriptine; D013469:Sulpiride