Increased hepatic production of alpha-amino-n-butyric acid after chronic alcohol consumption in rats and baboons.

Chronic alcohol consumption produces an increase in plasma alpha-amino-n-butyric acid (AANB) in humans. The mechanism of this increase was investigated in experimental animals. In the rat, administration of ethanol as 36% of total calories for 4--6 wk produced a threefold rise in plasma AANB associated with a sixfold increase in hepatic AANB. The increased gradient from liver to plasma suggested enhanced hepatic production. This was verified in liver slices from these animals: They showed a twofold increase in hepatic production of AANB. In the baboon, hepatic vein catheterization studies revealed a marked stimulation in splanchnic release of AANB after chronic but not acute alcohol consumption. Liver slices from these animals showed a two- to threefold increase in AANB production. Thus, increased hepatic production of AANB may explain the increased plasma levels seen in experimental animals and humans after chronic alcohol consumption.