TY - JOUR T1 - A Photochemical Affinity-Labelling Reagent for the Opiate Receptor(s) JF - Molecular Pharmacology JO - Mol Pharmacol SP - 601 LP - 611 VL - 8 IS - 6 AU - BETTY A. WINTER AU - AVRAM GOLDSTEIN Y1 - 1972/11/01 UR - http://molpharm.aspetjournals.org/content/8/6/601.abstract N2 - A radioactive analogue of levorphanol, [3H]N-β-(p-azidophenyl)ethylnorlevorphanol (compound 6), has been synthesized as a photochemical affinity label for the opiate receptor site(s). It has potent opiate-like pharmacological activity in whole mice and isolated intact guinea pig ileum Upon photolysis of the analogue in the presence of bovine serum albumin as a test protein, radioactivity is incorporated into the protein. Photolysis of the analogue in the presence of total particulate matter from whole mouse brain results in incorporation of radioactivity into a pellet insoluble in water and organic solvent. This incorporation is significantly but incompletely blocked by both levorphanol and dextrorphan. Incorporation into guinea pig ileum longitudinal muscle strips is also observed but is not significantly blocked by levorphanol or dextrorphan. The implications of the results are discussed. ACKNOWLEDGMENTS Our sincere gratitude is expressed to the following who made this work possible: Professor H. S. Mosher of the Stanford Chemistry Department, for use of his chemical laboratory; Professor L. M. Stephenson of the Stanford Chemistry Department, for helpful discussions relative to photochemistry; Barbara Judson, for a variety of technical assistance; Hoffmann-La Roche, Inc., for generous supplies of levorphanol tartrate, dextrorphan tartrate, and norlevorphanol hydrochloride; and Endo Laboratories, for a gift of naloxone hydrochloride. ER -