Relationoships between hetatic encephalopathy and GABA in acute liver failure

This investigation was aimed to clarify the relationships between hepatic encephalopathy and GABA, clinically and experimentally. In the patients with acute liver failure, the serum levels of GABA-like activity were not ralized significantly as compared with the controls. However, marked increase of GABA-like activity was observed in the patients showing coma grade V, in whom gastrointestinal bleeding was complicated. The serum levels of GABA-like activity did not show any correlation with the serum ammonia and ammino acid imbalance. In the animal study using rats carrying actue liver failure, the serum levels of GABA-like activity never changed, in spite of the increase of aromatic ammino acid. While GABA-like activity in the hippocampus were ralized and the specific binding sites of ^3H-muscimol decreased in the early stage of acute liver failure, but these levels recovered in spite of the porgression of liver failure. In conclusion, our data did not always support the hypothesis that GABA might play an important role for the induction of hepatic encephalopathy.