title: 16-Me cyprenorphine (RX 8008M): a potent opioid antagonist with some delta selectivity.
abstract: 16-Me cyprenorphine (RX 8008M) has been investigated in a number of isolated tissue preparations and found to be a pure opioid antagonist with Ke values at the delta, mu and kappa receptors of 0.73, 1.77 and 59.6 nM respectively. Comparisons of the mu, kappa and delta Ke values with a number of other antagonists in the mouse vas deferens have been made and show that the 16-Me substituent results in a marked enhancement of delta activity, making RX 8008M the most selective non-peptide delta antagonist available at the present time.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D008297:Male; D051379:Mice; D009019:Morphinans / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects*; D017465:Receptors, Opioid, delta; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D009019:Morphinans; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; C051207:16-methylcyprenorphine