Hepatic and intestinal gamma-glutamyltranspeptidase activity: Its activation by chronic ethanol administration

Brain γ-Glutamyltransferase Levels in Alcohol-Fed Rabbits

“…In consequence of the combined effects of duration of alcohol intake and of diet, when animals fed alcohol for only 3 months were compared with the restricted-diet controls, sig nificantly reduced brain GGTP was seen in all brain areas examined, whereas when all test and control animals were compared only the cere bral cortex and mid-brain/striatum showed sig nificant enzyme reduction. Reduction in brain GGTP in the alcohol-fed rabbits was unexpected, and contrasts with the induction of the enzyme in human liver that is thought to follow excess alcohol intake (4), with our observed concomitant increase in the rabbit liver GGTP and with the reported induc tion of the enzyme by alcohol in rat liver (11,12). In rat brain an increase in GGTP activity reduced GGTP activity was observed at each brain site.…”

Activity of Gamma-Glutamyl Transpeptidase in Human Fetal Membranes

“…It is involved in the trans port of amino acids and peptides across cell membranes [2], and in the metabolism of glutathione as it is the only biological means of glutathione degradation [3]. GGT is widely distributed in mammalian tissues [4] and is especially active in epithelial tissues such as the kidney [5], intestine [6] and mammary [7], Its presence in the placentae and changes in enzyme activity during pla cental growth and development have been shown recently [8], Although the fetal mem brane is believed to be a tissue of major importance in the transport of various com pounds and water, the activity of GGT has not been studied previously. In this study, we aimed to investigate GGT activity in human fetal membranes using biochemical methods.…”

Evaluation of the Oxidative Stress in Chronic Alcoholics

“…In our study, age and the BMI were ruled out as the confounders of the plasma GGT difference between non-drinkers and age-matched alcoholics, because the means of age and the BMI did not differ significantly between the two groups. Chronic alcohol consumption results in the proliferation of the smooth endoplasmic reticulum (the site of the intracellular GGT activity) and the induction of the liver derived enzymes, which include GGT [24,25]. This might be responsible for the increased plasma GGT activity in chronic alcoholics.…”