Significance of serum gamma glutamyl transpeptidase as a marker of alcoholism.
To study the effect of chronic ethanol administration on the activity of gamma glutamyl transpeptidase (GGTP) in various tissues, female rats were pair-fed liquid diets with 36% of total calories either as ethanol or as isocaloric carbohydrate (controls). Six weeks of ethanol feeding resulted in a significant increase of cytochrome P450 content. Hepatic microsomal GGTP activity was almost doubled after ethanol feeding whether expressed per g of liver or per mg of microsomal protein. Furthermore, intestinal GGTP activity was significantly enhanced after ethanol, whereas there was no change in the enzyme activity in either kidney or pancreas. There was a concomitant elevation of plasma GGTP activity. Phenobarbital administration to rats resulted in an enhancement of GGTP activity in the liver whether given orally or intraperitoneally. In addition, intestinal GGTP activity after oral phenobarbital was also significantly increased, although its activity after intraperitoneal administration was not enhanced. These results suggest that enhanced hepatic and intestinal GGTP activities may contribute, at least in part, to an increased level of serum GGTP frequently seen in chronic alcoholics.
D000437:Alcoholism / Q000201:enzymology*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005260:Female; D006801:Humans; D008566:Membranes / Q000378:metabolism; D008862:Microsomes, Liver / Q000201:enzymology; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D005723:gamma-Glutamyltransferase / Q000097:blood*
D003577:Cytochrome P-450 Enzyme System; D005723:gamma-Glutamyltransferase; D010634:Phenobarbital