Sympathetic ganglion cell x neuroblastoma hybrids with opiate receptors

Abstract A number of cultured cells of nerve or smooth muscle origin have been surveyed for stereospecific binding of either [ 3 H] naloxone or [ 3 H]dihydromorphine. Of the cell lines tested, three somatic cell hybrids, TCX17, NX1 and Z5, exhibited substantial specific binding of both naloxone and dihydromorphine. In addition, specific binding of [ 3 H]naloxone by the hybrid clone 108cc15 was confirmed. The neuroblastoma, smooth muscle, glial, and other hybrid cell lines demonstrated little or no specific binding. Specific binding of [ 3 H] dihydromorphine is dose dependent. Dissociation constants for the three hybrid clones range from 15 to 90 nM and maximal binding values range from 75 to 225 fmoles/mg of protein. The order of effectiveness of other opiates in displacing bound ( 3 H]dihydromorphine in TCX17 cells agrees well with that found in brain. Sodium ions selectively inhibit agonist binding (dihydromorphine) but not antagonist binding (naloxone), while potassium and magnesium salts have little effect on either.