Analysis of the role of delta opioid receptors in gastroprotection in the rat.
The effect of delta opioid agonists - [D-Ala2, D-Leu5]-enkephalin (DADLE), [D-Pen2, D-Pen5]-enkephalin (DPDPE) and deltorphin II - on acidified ethanol induced gastric mucosal lesions was studied in the rat compared with that of morphine. It was found that DADLE, DPDPE, deltorphin II and morphine exerted a dose-dependent inhibition on the mucosal lesions injected subcutaneously, their ID50 values were 0.037, 1.8, 3.5 and 0.35 micromoles/kg, respectively. Naltrindole (10 mg/kg sc.), the selective delta opioid receptor antagonist, inhibited the gastroprotective effect of DADLE, DPDPE and deltorphin II, but it failed to antagonise the effect of morphine. Our results suggest that 1. delta receptors are involved in opioid-mediated gastroprotection, 2. ethanol-induced gastric mucosal damage in the rat may be a quick, simple in vivo model for screening opioid delta receptor agonists and antagonists in the periphery.
Gyires
K
K
Department of Pharmacology, Semmelweis University of Medicine, Budapest, Hungary.
Rónai
A Z
AZ
Tóth
G
G
Darula
Z
Z
Fürst
S
S
D000700:Analgesics / Q000627:therapeutic use; D000818:Animals; D001665:Binding Sites; D004305:Dose-Response Relationship, Drug; D020881:Enkephalin, D-Penicillamine (2,5)-; D016308:Enkephalin, Leucine-2-Alanine / Q000627:therapeutic use; D004745:Enkephalins / Q000627:therapeutic use; D000431:Ethanol / Q000633:toxicity; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D007082:Ileum / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000627:therapeutic use; D009130:Muscle, Smooth / Q000187:drug effects / Q000648:ultrastructure; D009842:Oligopeptides / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D017465:Receptors, Opioid, delta / Q000819:agonists* / Q000502:physiology*; D017450:Receptors, Opioid, mu / Q000502:physiology; D013270:Stomach / Q000187:drug effects / Q000648:ultrastructure; D013272:Stomach Diseases / Q000139:chemically induced / Q000517:prevention & control*; D014649:Vas Deferens / Q000187:drug effects / Q000648:ultrastructure
D000700:Analgesics; D004745:Enkephalins; D009842:Oligopeptides; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; C060209:deltorphin II, Ala(2)-; D000431:Ethanol; D016308:Enkephalin, Leucine-2-Alanine; D009020:Morphine; D020881:Enkephalin, D-Penicillamine (2,5)-