Coenzyme Q10 and Succinate-Tetrazolium Reductase Activity of Proliferative Lesions of Liver.

Abstract

Recent work employing the tetrazolium salt, 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT), has indicated that a quinone, presumably coenzyme Q10 (CoQ10). serves as an intermediate electron transport agent in the succinate-INT reductase reaction. Quantitative histochemical studies of sections of normal liver, regenerating liver and Novikoff hepatoma demonstrated that the succinate-INT and alpha-glycero-phosphate-INT reductase systems of these tissues are not saturated with respect to quinone. Compared to normal liver, the degree of unsaturation is considerably greater in regenerating liver and hepatoma and largely accounts for those low reductase activities observed in these 2 tissues. The response of sections of regenerating liver and hepatoma to CoQ10 and menadione differ. CoQ10 is very effective in hepatoma. In regenerating liver CoQ10 is relatively ineffective whereas the enhancement of reductase activity brought about by menadione is profound.