Sympathetic Ganglion Cell X Neuroblastoma Hybrids with Opiate Receptors

A number of cultured cells of nerve or smooth muscle origin have been surveyed for stereospecific binding of either H3-naloxone or H3-dihydromorphine. Four somatic cell hybrids, TCX17, NX1, Z5, and 108CC15, exhibited substantial specific binding of both naloxone and dihydromorphine. The neuroblastoma, smooth muscle, glial, and other hybrid cell lines demonstrated little or no specific binding. The specific binding of H3-dihydromorphine to TCX17, NX1, and Z5 is dose dependent with dissociation constants ranging from 15-90 nM and maximum binding values ranging from 75-225 fmoles/mg protein. The rank order effectiveness of other opiates in displacing bound H3-dihydromorphine in TCX17 cells agrees well with that found in brain. Sodium ion selectively inhibits agonist binding (dihydromorphine) but not antagonist binding (naloxone) while potassium of magnesium salts have little effect on either. The presence of drug receptors in these cell lines suggest that they may well provide ideal model systems for investigations into the mechanism of action of drugs and other toxicological agents on the central nvervous system. (Author)