Change in the charactertistics of 3H-spiperone binding to rat striatal membranes after acute chlorpromazine administration: effects of buffer washing of membranes.

Abstract After intraperitoneal injections of 3 H-spiperone into the rat, brain membrane preparations retain the majority of the radioactivity even after several buffer washes. With 3 H-spiperone as ligand, dissociation constants were significantly elevated and maximum binding unchanged in rat striatal membranes after acute intraperitoneal injection of chlorpromazine (14 mg/kg). It is suggested that in studies of post-mortem brains of schizophrenics that contain neuroleptics specific 3 H-spiperone binding will be lowered by competition from residual drug in membrane preparations and valid comparisons of 3 H-spiperone binding to preparations from control and schizophrenic brains can only be made if maximum binding values are determined.