(+)-6,7-BENZOMORPHAN SIGMA LIGANDS STIMULATE DOPAMINE SYNTHESIS IN RAT CORPUS STRIATUM TISSUE

The benzomorphan sigma-ligands, (+)-N-allylnormetazocine (NANM) and (+)-pentazocine, but not (+)-cyclazocine, stereospecifically stimulated dopamine synthesis in minces of rat corpus striatum by 15-23% over basal values at 0.1-1.0-mu-M. The effect of (+)-NANM and (+)-pentazocine was blocked by the reported sigma-antagonist, BMY-14802 but not by the opiate antagonist naloxone. These results suggest that these (+)-benzomorphans may act as agonists at putative sigma-heteroreceptors on striatal nerve terminals, or through an indirect mechanism, to modulate dopamine synthesis.