u-50488 and Cadaver

The distribution and quantification of opioid receptor types in post-mortem human pituitary cryostat sections was determined by quantitative in vitro receptor autoradiography. Highly specific radioligands were used for each opioid receptor type i.e. [125l]-FK-33-824 for mu-opioid sites, [125l][D.Ala2]-Deltorphin-l for delta-opioid sites and 3H-U69,593 for kappa-opioid sites. None of the five specimens tested exhibited any labeling in the anterior lobe of the pituitary for the three radioligands. As for the posterior pituitary, all 5 specimens contained both mu and kappa-opioid binding sites whereas none of them showed delta-binding sites. The presence of both mu- and kappa-opioid binding sites in the human posterior pituitary contrasts with previous findings in the rat where only kappa-sites have been found. The present study could contribute to understanding of the functional action of opioids in the human pituitary.

Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Adult; Benzeneacetamides; Binding Sites; Binding, Competitive; Cadaver; D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalins; Female; Humans; Male; Middle Aged; Narcotics; Oligopeptides; Pituitary Gland, Posterior; Pyrrolidines; Receptors, Opioid; Tissue Distribution