Effect of Carbon Tetrachloride Intoxication on the Type Conversion of Xanthine Dehydrogenase Into Xanthine Oxidase in Rats

The conversion of xanthine dehydrogenase (type D) into xanthine oxidase (type D) was significantly increased in serum and liver of all $CCI_4$ treated rats on the necrosis and early cirrhosis stage of liver tissue. In the pretreatment of prednisolone, the ratio of type O per type O + D showed the decreasing tendency in serum, but the significant decrease in liver. In vitro, the conversion of liver xanthine oxidase from type D into type O was markedly increased by following preincubation with lysosomal fraction. The type conversion of xanthine oxidase may be caused by protelytic enzymes in lysosome.