Changes in hepatic and serum gamma-glutamyltransferase activities following chronic ethanol intake in rats

The effect of chronic ethanol consumption on serum and liver gamma-glutamyltransferase (GGT) activities was studied in male Wistar rats. Animals were fed for 1-9 weeks a liquid diet containing 36% of total energy as ethanol or isocaloric carbohydrates. Compared to control diet, chronic ethanol significantly and progressively increased serum activity from 3 weeks of treatment. Liver GGT activity was also enhanced although changes were not parallel to those found in serum. Chronic ethanol intake led to an enhancement of liver glutathione concentration with a 45% increase at 3 weeks of treatment and a decrease thereafter. It is suggested that the increased hepatic GGT activity is not the only determinant of the enhanced serum levels of the enzyme and that it is not related to the modifications of liver glutathione content induced by ethanol consumption.