title: Lack of postulated opiate-receptor antagonistic properties of compound 48/80.
abstract: The previously suggested opiate-receptor antagonistic properties of compound 48/80 were checked both in vivo and in vitro. In electrically stimulated guinea pig ileum and rat vas deferens preparations compound 48/80 did not reverse the inhibition of the twitches caused either by morphine or Met5-enkephalin. In mice hot-plate test compound 48/80 did not decrease the analgesic activity of morphine. In radioreceptor studies compound 48/80 shows rather low affinity to the 3H-naloxone receptor sites from striatal homogenates of the rat, as compared to non-labelled naloxone and on the other hand it produced moderate, as compared to d-butaclamol, displacement of 3H-spiroperidol from rat striatal homogenates. The variation of composition of various polymers making compound 48/80 is suggested for explanation of obtained results.
mesh_terms: D000700:Analgesics; D000818:Animals; D001667:Binding, Competitive; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009270:Naloxone / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects*; D013134:Spiperone / Q000378:metabolism; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
chemical_list: D000700:Analgesics; D011957:Receptors, Opioid; D009270:Naloxone; D003189:p-Methoxy-N-methylphenethylamine; D013134:Spiperone