Effect of acute and chronic phenobarbital treatment on gaba and other amino acids contents in seven regions of the rat brain.

Abstract

Effects of acute and chronic phenobarbital treatment on GABA, glu, asp, gly and taurine contents in 7 regions of the rat brain were investigated. Rats treated chronically with phenobarbital maintained the hepatic changes known to follow short-term treatment and high phenobarbital levels in the liver, brain and serum. After withdrawal, spontaneous convulsions were first observed when phenobarbital level in the serum fell to .apprx. 15 .mu.g/ml. Chronic phenobarbital treatment resulted in the decrease of GABA content in the cerebral cortex, midbrain, hypothalamus, striatum and hippocampus. At 2 days after withdrawal, glu and asp contents were decreased and taurine content was increased with recovery of GABA content. Acute phenobarbital treatment resulted in the decrease of GABA and glu contents and the increase of taurine content. The changes of amino acid contents were different among 7 regions of the rat brain, but phenobarbital distributed uniformly after acute and chronic treatment. GABA apparently participated in phenobarbital action, and abstinence syndrome may arise from a deficiency of GABA.