QUANTITATIVE ENZYME HISTOCHEMISTRY OF NORMAL AND INJURED LIVERS

Abstract

G6PD and ICD activity within the hepatic lobule was determined quantitatively by the ultramicrochemical method of Lowry in CCl4-injured liver of rats and their controls. The activity of G6PD, ICD and NADPH diaphorase was evaluated simultaneously by two histochemical staining methods: the Meijer method using phenadine methosulfate (PMS) and menadione as intermediate electron acceptors and the Pearse method without using PMS or menadione. By the ultramicrochemical method, the G6PD activity increased remarkably and ICD activity decreased in the central area which was most severely affected in CCl4-injured rats. By the Pearse method, the activities of these three enzyme decreased or diminished in the central area. The Meijer method, however, demonstrated considerable G6PD and ICD activity in the central area. Further examination confirmed that such discrepancies were related to NADPH diaphorase which is generally considered the rate-limiting factor in the staining of NADP-linked dehydrogenases. Increased G6PD activity and considerable ICD activity were detected even in necrotic cells by the ultramicrochemical method and the Meijer method.