Effect of Heat-treated Ceruloplasmin on the Hepatic xanthine Oxidase Activity and Type Conversion

The effect of ceruloplasmin or copper ion on hepatic xanthine oxidase activity and type conversion was investigated using rat liver in vitro. It was observed that ceruloplasmin increased xanthine oxidase type conversion depending on duration of its storage. Xanthine oxidase (type O) activity and type conversion in incubation mixture was increased by the addition of heated celuroplasmin in a temperature dependent manner. The type conversioin of xanthine oxidase induced by heated ceruloplasmin was retumed to normal by the tratment with DTT or penicillamine. The effect of copper ion on type conversion of xanthine oxidase was similar to that of heated ceruloplasmin.