Biochemical and behavioral studies of D1 dopamine receptors utilizing SCH 23390.

Abstract

Previous research has demonstrated the existence of two distinct dopamine receptor subtypes (Kebabian & Calne, 1979; Creese et al., 1983), possessing unique pharmacologic and biochemical properties. D1 dopamine receptors stimulate adenylate cyclase activity (Hyttel, 1978), while D2 dopamine receptors inhibit this enzyme (Stoof and Kebabian, 1981; Onali et al., 1984; Battaglia et al., 1985). However, both receptor subtypes co-exist in many tissues making the determination of their respective physiological and behavioral roles difficult. All neuroleptics, commonly used drugs in the treatment of schizophrenia, have been shown to be either mixed D1/D2 dopamine receptor antagonists or selective D2 dopamine receptor antagonists. Thus, D2 dopamine receptors have been implicated as the site mediating the antipsychotic and antidopaminergic activity of neuroleptics (Creese et al., 1976; Seeman et al., 1976). By inference, D2 dopamine receptors have been considered to mediate dopaminergic agonists’ behavioral effects as well (Seeman, 1981).