REDUCED CONCENTRATIONS OF THE ALPHA-SUBUNIT OF GTP-BINDING PROTEIN GOIN SCHIZOPHRENIC BRAIN

Concentrations of the a-subunits of GTP-binding protein, Go (Go alpha) and of Gi 2 (Gi 2 alpha) in 6 areas (the hippocampus, parahippocampus , putamen, caudate head, orbital frontal cortex, and lateral temporal cortex) of control and schizophrenic postmortem brains were investigat ed using the highly sensitive enzyme immunoassay method. There was a s ignificant decrease in Go alpha in the hippocampus and caudate head of the right hemisphere in schizophrenic patients compared to controls; the ANOVA (a general linear model; SAS Type II) demonstrated a signifi cant diagnosis x side interaction only in the hippocampus. In other ar eas of the brain, analysis by grouping under diagnosis, side, age, gen der, and postmortem delay showed no significant deviations in Go alpha between controls and schizophrenics. The concentrations of Gi 2 alpha did not differ significantly in any area. These findings contrasted w ith the results yielded by ADP-ribosylation, which showed decreased pe rtussis toxin ADP-ribosylated amounts in the hippocampus and putamen o f the contralateral (left) hemisphere. Some abnormal receptor - Go or Gi 1 signalling in hippocampus, putamen or caudate head may be involve d in the pathogenesis of schizophrenia.