The possible modulation of morphine analgesia by the supramolecular GABA receptor complex.
In the present study, the mechanism of the antagonistic action of 0.5 mg/kg diazepam on the analgesic effect of morphine was investigated. While Ro 15-1788, a benzodiazepine receptor antagonist, was found to partially reverse the inhibitory action of diazepam on morphine analgesia, a chloride channel blocking agent, picrotoxin, produced complete antagonism of the action of diazepam. Furthermore, picrotoxin potentiated the partial antagonistic effect of Ro 15-1788 at a normally ineffective dose to affect the 0.5 mg/kg diazepam-morphine dose-response curve. These overall effects of picrotoxin on the supramolecular GABA receptor complex are discussed.
D000700:Analgesics; D000818:Animals; D003975:Diazepam / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005442:Flumazenil / Q000494:pharmacology; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D010852:Picrotoxin / Q000494:pharmacology; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*
D000700:Analgesics; D003975:Diazepam; D005442:Flumazenil; D009020:Morphine; D010852:Picrotoxin; D011963:Receptors, GABA-A