Do kappa opioids mimic sigma agonists as amino acid antagonists?
The kappa opioids tifluadom and U-50,488 H, when tested on spinal neurones of rats in vivo and frogs in vitro, had no selective effect on responses to microelectrophoretically or bath applied N-methyl-D-aspartate, quisqualate or kainate. In the same preparations ketamine selectively reduces responses to N-methyl-D-aspartate. Amino acid antagonism by dissociative anaesthetics and sigma opioids is thus not mediated by that binding site which kappa and sigma opioids have been reported to have in common.
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000596:Amino Acids / Q000037:antagonists & inhibitors*; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology; D004586:Electrophoresis; D004723:Endorphins / Q000494:pharmacology*; D066298:In Vitro Techniques; D007649:Ketamine / Q000494:pharmacology; D009498:Neurotoxins / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D011894:Rana pipiens; D011896:Rana temporaria; D051381:Rats; D011957:Receptors, Opioid / Q000502:physiology*; D017473:Receptors, Opioid, kappa; D017480:Receptors, sigma
D000596:Amino Acids; D000700:Analgesics; D004723:Endorphins; D009498:Neurotoxins; D011759:Pyrrolidines; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D017480:Receptors, sigma; D001569:Benzodiazepines; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D007649:Ketamine; C035470:tifluadom