GAMMA-HYDROXYBUTYRATE RECEPTOR-BINDING IN RAT-BRAIN IS INHIBITED BY GUANYL NUCLEOTIDES AND PERTUSSIS TOXIN

gamma-Hydroxybutyrate is an endogenous substance of mammalian brain wh ich is primarily derived from GABA. This compound exhibits neuromodula tory influences on dopamine and serotonin synthesis and release in rat brain. These effects are mediated by specific brain receptors which a re mainly distributed in the hippocampus, cortex and striatum. In orde r to characterize this type of receptor, we have studied the possibili ty that guanosine triphosphate (GTP) and/or pertussis toxin mediated m odification of the affinity for gamma-hydroxybutyrate binding to the r eceptor. Results presented in this paper favor the presence of guanine nucleotide binding proteins (G(o) or G(i) family), which are coupled to the gamma-hydroxybutyrate receptor, modifying the high-affinity gam ma-hydroxybutyrate binding. We conclude that the gamma-hydroxybutyrate receptor in brain belongs to the G-protein family of receptors.