Effect of pertussis toxin on normorphine-dependence and on acute inhibitory effects of normorphine and clonidine in guinea-pig isolated ileum.
In guinea-pig isolated ileum from animals pretreated with Pertussis toxin, the acute inhibitory effects of normorphine and clonidine on electrically induced contractions were markedly attenuated whilst responses to acetylcholine and electrical stimulation were unaltered. Pertussis toxin treatment also reduced naloxone-precipitated withdrawal contractures in normorphine-dependent tissues. These results suggest that the acute and chronic effects of normorphine are mediated by the same mechanism, namely that of adenylate cyclase inhibition.
D037361:Adenylate Cyclase Toxin; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D003000:Clonidine / Q000494:pharmacology*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009022:Morphine Derivatives / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella
D037361:Adenylate Cyclase Toxin; D001427:Bacterial Toxins; D009022:Morphine Derivatives; D010566:Virulence Factors, Bordetella; D009270:Naloxone; D037342:Pertussis Toxin; D003000:Clonidine; C010616:normorphine