EFFECT OF GLUTATHIONE DEPLETION ON THE CONVERSION OF XANTHINE DEHYDROGENASE TO OXIDASE IN RAT-LIVER

The ability of endogenous glutathione (GSH) to modify the activity of the enzyme xanthine oxidase (XO) in rat liver was investigated. The ef fect of hepatic GSH depletion on the conversion of xanthine dehydrogen ase (XDH) (EC 1.1.1.204) to XO (EC 1.1.3.22) was determined 10 min aft er i.p. administration of different amounts of diethylmaleate to faste d rats. After administration of 400 mg/kg, total hepatic non-protein G SH (reduced + oxidized GSH) decreased significantly to 14% of controls . In this condition the level of oxidized GSH was unchanged and no lip id peroxidation was observed, while a significant increase of reversib le XO and a minor increase of the irreversible form of the enzyme was detected.