Changes in enzyme activities in the urine and tissues of rats fed sodium o-phenylphenate

The activities of certain enzymes in the urine and tissues of rats given 2% sodium o- phenylphenate in the diet for 20 wk were examined. Urinary gamma-glutamyl transpeptidase (gamma GTP) decreased immediately after the start of feeding of the treated diet and its activity remained low for 20 wk. The gamma GTP and alkaline phosphatase (ALP) activities in kidney homogenate decreased to about 80% of the control at 20 wk, but G6PD activity was significantly increased; Na,K-ATPase was unchanged. On the other hand, the gamma GTP activity in the liver homogenate of treated rats was increased to about eight times that of the controls, the G6PD activity showed a significant increase, but the ALP and Na, K-ATPase activities were not significantly different from the control values. The glutathione concentration in the livers of treated rats was significantly reduced.