Involvement of central K(ATP) channels in the gastric antisecretory action of alpha2-adrenoceptor agonists and beta-endorphin in rats.
The intracerebroventricularly (i.c.v.) injected presynaptic alpha2-adrenoceptor agonists, clonidine and oxymetazoline, exerted a dose-dependent inhibition on the gastric acid secretion in pylorus-ligated rats; the ED50 values were 20 and 7.5 nmol/rat, respectively. Moreover, beta-endorphin, given i.c.v., also decreased acid secretion (ED50=0.25 nmol/rat i.c.v.). The antisecretory effect of these compounds was highly reduced by glibenclamide (10 nmol/rat i.c.v.), a selective blocker of K(ATP) channels. These results suggest that K(ATP) channels in the central nervous system are likely to be involved in the centrally initiated antisecretory action of both alpha2-adrenoceptor agonists and beta-endorphin.
Müllner
Katalin
K
Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, 1445 POB 370, Budapest, Hungary.
Rónai
Andrá Z
AZ
Fülöp
Katalin
K
Fürst
Susanna
S
Gyires
Klára
K
D058647:Adrenergic alpha-2 Receptor Agonists; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects* / Q000378:metabolism; D003000:Clonidine / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D005905:Glyburide / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D008026:Ligation; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D010109:Oxymetazoline / Q000494:pharmacology; D015221:Potassium Channels; D011708:Pylorus / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism; D013270:Stomach / Q000187:drug effects*; D001615:beta-Endorphin / Q000494:pharmacology*
D058647:Adrenergic alpha-2 Receptor Agonists; D000316:Adrenergic alpha-Agonists; D007004:Hypoglycemic Agents; D008565:Membrane Proteins; D015221:Potassium Channels; D018341:Receptors, Adrenergic, alpha-2; C117780:mitochondrial K(ATP) channel; D001615:beta-Endorphin; D010109:Oxymetazoline; D003000:Clonidine; D005905:Glyburide