Relationship between plasma ammonia concentration and beta-N-acetylhexosaminidase isoenzyme activities in liver cirrhosis

Ammonia is known to increase the secretion of beta -N-acetylhexosaminidase (Hex) to the extracellular medium in cultured human fibroblasts and Hep G2 cells. We examined 35 patients with liver cirrhosis and the results reveale d a significant increase for the plasma activities of total Hex and its iso enzymes Hex A and Hex B (p < 0.001). The partial correlations, with other b iochemical markers of liver injury constant, between plasma ammonia concent ration and the activity (r = 0.658) and the proportion in percentage of the Hex B isoenzyme (r = 0.692) were statistically significant (p < 0.001). Th e increased concentration of ammonia could explain, at least partially, an increased secretion of Hex B isoforms to the plasma in patients with liver disease.