Multiplicity of opiate receptors in different species.
Three populations of opiate binding sites (mu, delta and kappa) could be distinguished by displacement studies with the mu-agonist (D)-Ala2-MePhe4-Glyol5-enkephalin and the kappa-agonist [3H](-)-bremazocine in brain membranes of different species. Whereas brain membranes from pig or guinea-pig and human cortical membranes had a proportion of approximately 35-50% kappa-, 29-40% mu-, and 21-30% delta-binding sites, rat membranes contained much less kappa-sites (12% kappa, 62% mu and 25% delta).
D000368:Aged; D000700:Analgesics / Q000378:metabolism; D000818:Animals; D001575:Benzomorphans / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007700:Kinetics; D008297:Male; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D013045:Species Specificity; D013552:Swine
D000700:Analgesics; D001575:Benzomorphans; D011957:Receptors, Opioid; C027248:bremazocine