[Quantitative histochemical study of the effect of benzodiazepine tranquilizers on cerebral GABA-transaminase activity].

The effect of diazepam and nitrazepam (0.5, 1, 2.5, and 5 mg/kg) on GABA-transaminase activity in the rat cerebellar cortex and hippocampus was investigated by quantitative histochemistry. Both the drugs suppressed the enzyme activity in the hippocampus; the maximal effect was produced by diazepam. It is suggested that the observed alterations are caused by the enzyme inhibition and also by a decrease of GABA turnover rate.