Blood and tissue distribution of gamma glutamyl transferase in the cow.

To test the hepatic specificity of gamma-glutamyl transferase in the cow, the tissue distribution of this enzyme was studied in 10 healthy adult cows. It was located mainly in kidney, pancreas, and liver. The relative hepatic specificity of this enzyme indicated that measurement of its activity in serum could be a valuable test of hepatic damage in the cow. The blood activity measured within 54 plasmas and 54 serums of apparently healthy animals was almost the same, 17.7 +/- 5.7 U/liter for plasma and 18.6 +/- 6.2 U/liter for serum.