Comparative study on the correlation of plasma gamma-aminobutyric acid andpipecolic acid with liver function in patients with liver cirrhosis

gamma-Aminobutyric acid (GABA) is an inhibitory neurotransmitter, elevated in plasma of patients with liver cirrhosis. Pipecolic acid (PA), a metaboli te of lysine, and known to be a GABA receptor agonist, is also seen high le vels in the plasma. To clarify the relationship of GABA, PA and liver funct ion, plasma GABA and PA in three groups of chronic liver diseases (compensa ted cirrhosis, decompensated cirrhosis and decompensated cirrhosis with hep atic encephalopathy, HE) were analyzed and their liver functions were compa red. This analysis demonstrated that both plasma GABA and PA were higher in these patients than in normal subjects. Plasma PA, but not plasma GABA, wa s closely correlated with plasma ammonia concentration in each group. No co rrelation was noted between plasma GABA and PA. in each group. Plasma pipec olic acid was significantly higher in patients with esophageal varices than in patients with no varices. These findings suggest that increased PA may reflect the degree of portal hypertension. Although both GABA and PA are in creased in chronic liver disease, they may have a different origin and disa ppearance rate including metabolic mechanism. (C) 2000 Elsevier Science ire land Ltd, All rights reserved.