HISTOCHEMICAL STUDIES OF FATTY ACID SYNTHESIZING ENZYMES IN FATTY LIVERS INDUCED BY ETHIONINE, CARBON TETRACHLORIDE AND ETHANOL

Abstract

Fatty acid synthesizing enzyme activity was studied histochemically in the hepatic lobules of young male mice with fatty livers induced by ethionine, carbon tetrachloride or ethanol. In fatty livers induced by ethionine or carbon tetrachloride, even when the fatty changes were very slight, enzyme activity was decreased throughout the entire lobules and in the centrilobular areas there was sometimes very little or no activity. In livers with mild to moderate fatty changes very little enzyme activity was found only in the peripheral areas and in some cases no enzyme activity was observed throughout the lobules. Severe fatty changes caused complete loss of enzyme activity. In ethanol-induced fatty liver, no change in enzyme activity was observed even in livers with moderate to somewhat severe fatty changes. But severe fatty liver developed when the dose of ethanol was increased, and enzyme activity became negative. The change in intensity and distribution of enzyme activity in fatty livers induced by ethionine and by carbon tetrachloride was similar, whereas the change was different in fatty liver induced by ethionine or carbon tetrachloride from that in fatty liver induced by ethanol. In fatty livers induced by ethionine and carbon tetrachloride, an inverse relationship was observed between the distribution of fat droplets and fatty acid synthesizing enzyme activity.