Effects of zinc on hepatic ornithine transcarbamylase (OTC) activity.

The aim of the study was to examine the effects of oral zinc supplementation on liver ornithine transcarbamylase activity (OTC), a key enzyme in the urea cycle, in cirrhotic rats. OTC was studied in two groups of rats treated with carbon tetrachloride (CCl4): the first received zinc in the drinking water during the induction of cirrhosis; the second was the control group. Cirrhotic rats which received zinc supplementation showed an increase in liver OTC activity, positively correlated with serum and hepatic zinc content. The results suggest that zinc dietary supplementation may modify hepatic OTC activity and, therefore, plasma ammonia levels in cirrhotic rats.