The effect of alpha 2-adrenoceptor agonists on the acid secretory responses of rat isolated gastric mucosa to electrical field stimulation.
The effects of clonidine, UK-14,304, noradrenaline, para-aminoclonidine and phenylephrine were examined on the acid secretory response of the rat isolated gastric mucosa preparation to electrical field stimulation. Clonidine, UK-14,304, noradrenaline and para-aminoclonidine but not phenylephrine (10 microM) reduced the response of the gastric mucosa stimulated at 2.5 Hz; gastric mucosae stimulated at higher frequencies were insensitive to the action of these alpha 2-adrenoceptor agonists. The inhibitory effect of the selective alpha 2-adrenoceptor agonist UK-14,304 was antagonized by idazoxan but not by prazosin. These findings indicate that clonidine and other alpha 2-adrenoceptor agents inhibit the acid secretory response of the rat gastric mucosa to electrical field stimulation by an action at alpha 2-adrenoceptors, which are probably located on cholinergic nerve terminals.
D000109:Acetylcholine / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D000068438:Brimonidine Tartrate; D004146:Dioxanes / Q000494:pharmacology; D004558:Electric Stimulation; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism* / Q000502:physiology; D006632:Histamine / Q000494:pharmacology; D019329:Idazoxan; D066298:In Vitro Techniques; D008297:Male; D010418:Pentagastrin / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000316:Adrenergic alpha-Agonists; D000959:Antihypertensive Agents; D004146:Dioxanes; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; D006632:Histamine; D010418:Pentagastrin; D000109:Acetylcholine; D011224:Prazosin; D019329:Idazoxan