GGT (formerly gamma-glutamyltranspeptidase) is located mainly in liver cells, to a lesser extent in kidney, and in much smaller quantities in biliary tract epithelium, intestine, heart, brain, pancreas, and spleen. Some GGT activity seems to reside in capillary endothelial cells. The serum GGT level is increased in the newborn but declines to adult levels by […]