Effects of sigma ligands on the cloned mu-, delta- and kappa-opioid receptors co-expressed with G-protein-activated K+ (GIRK) channel in Xenopus oocytes.

ABSTRACT: 1. Taking advantage of the functional coupling of the opioid receptors with the G-protein-activated K+ (GIRK) channel, we investigated the effects of sigma (sigma) ligands of various structural and pharmacological classes, (+)-N-allylnormetazocine ((+)-SKF10047) and (+)-cyclazocine, (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3PPP), 1,3-di-(2-tolyl)guanidine (DTG), carbetapentane and haloperidol, on the inward K+ current responses in Xenopus oocytes co-injected with each of the cloned mu-, delta- and kappa-opioid receptor mRNAs and the GIRK1 mRNA. 2. (+)-SKF10047 acted as a delta- and kappa-agonist (EC50 values (microM) = 0.618 and 0.652, respectively) and mu-antagonist (IC50 value (microM) = 8.51). (+)-Cyclazocine acted as a kappa-agonist and mu-antagonist (IC50 = 33.2). (+)-3PPP

SUBMITTER: Kobayashi T 

PROVIDER: S-EPMC1915734 | biostudies-literature | 1996 Sep

REPOSITORIES: biostudies-literature