title: Diprenorphine has agonist activity at opioid kappa-receptors in the myenteric plexus of the guinea-pig ileum.
abstract: The opioid agonist and antagonist activities of diprenorphine have been tested in four in vitro bioassay preparations. Diprenorphine is an antagonist at delta-receptors in the hamster vas deferens, at mu-receptors in the rat vas deferens and at kappa-receptors in the rabbit vas deferens. In the guinea-pig ileum it is an antagonist at mu-receptors and an agonist at kappa-receptors.
mesh_terms: D000818:Animals; D006224:Cricetinae; D004174:Diprenorphine / Q000494:pharmacology*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009019:Morphinans / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009197:Myenteric Plexus / Q000187:drug effects*; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects*; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D009019:Morphinans; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D004174:Diprenorphine; D009271:Naltrexone; C017120:chlornaltrexamine; C024524:beta-funaltrexamine