Interaction of leucine enkephalin with (3H)naloxone binding in rat brain: evidence for an opioid receptor complex.
We recently presented evidence that distinct morphine and enkephalin receptors coexist in an opioid receptor complex (Mol. Pharmacol. 21:548-557, 1982). In this paper, we present data which demonstrate that in the presence of sodium leucine enkephalin noncompetitively inhibits the binding of [3H]naloxone to a crude particulate fraction of rat brain. Since the binding site labeled by [3H]naloxone in the presence of sodium may be an alternate conformation of the morphine receptor, these data provide further evidence that morphine and enkephalin receptors are allosterically coupled.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D003496:Cyclazocine / Q000494:pharmacology; D004743:Enkephalin, Leucine / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009270:Naloxone / Q000378:metabolism*; D009994:Osmolar Concentration; D011485:Protein Binding; D011487:Protein Conformation; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*
D011957:Receptors, Opioid; C034565:naloxone receptor; D009270:Naloxone; D004743:Enkephalin, Leucine; D003496:Cyclazocine