Beta-funaltrexamine blockade of opioid-induced inhibition of somatostatin secretion from rat stomach.
Opioid peptides are potent inhibitors of gastric somatostatin secretion. In the current investigation the effect of mu-opioid receptor blockade on responses to [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin (DAGO) was studied. Gastric inhibitory polypeptide (GIP; 1 nM) -stimulated secretion of immunoreactive somatostatin was almost completely inhibited by DAGO (1 microM). The mu-receptor antagonists, beta-funaltrexamine and naloxonazine, blocked the effect of DAGO. Pretreatment of rats with beta-funaltrexamine, 24 h prior to perfusion, reduced the percentage inhibition by DAGO from 88.6 +/- 5.2% to 50.7 +/- 9.3%. These studies support the involvement of mu-opioid inhibitory receptors in the regulation of gastric somatostatin secretion.
McIntosh
C
C
Department of Physiology, University of British Columbia, Vancouver, Canada.
Yago
V
V
Kwok
Y N
YN
D000595:Amino Acid Sequence; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005749:Gastric Inhibitory Polypeptide / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008969:Molecular Sequence Data; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013004:Somatostatin / Q000378:metabolism*
D000700:Analgesics; D004745:Enkephalins; D009292:Narcotic Antagonists; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009270:Naloxone; D013004:Somatostatin; D005749:Gastric Inhibitory Polypeptide; D009271:Naltrexone; C024524:beta-funaltrexamine; C034643:naloxonazine