Selective alkylatation of dopamine D-2 and D-4 receptors in rat brain by N-(p-isothiocyanatophenethyl)spiperone

Effects of the D-2-like receptor alkylating agent NIPS (N-[p-isothiocyanato phenethyl]spiperone) on dopamine receptors in rat brain were characterized by radioreceptor assays and quantitative autoradiography. NIPS alkylated D- 2 and D-4 receptors concentration-dependently in brain sections and transfe cted cells. NIPS also alkylated both receptors dose-dependently in vivo, wi th no effect on dopamine D-1-like or serotonin 5-HT2 receptors at a dose th at occluded 75% of D-2 and D-4 receptors. Pretreatment with D-2-like recept or selective antagonist haloperidol completely blocked the effects of NIPS. The findings demonstrate that NIPS selectively alkylates D-2 and D-4 recep tors, indicating its potential utility for studies of these receptors. (C) 1999 Elsevier Science Ireland Ltd. Atl rights reserved.