[Mechanisms of reversibility of fatty degeneration]

Carnitine acetyltransferase (CAT) was determined electron microscopically and histochemically in hepatocytes of patients with cholecystitis and in hepatocytes of fasting rats. In the latter, tests for this enzyme were also done in subcutaneous tissue. Glycogen was determined histochemically in thin sections of hepatocytes from intact rats. CAT was found in mitochondria, microbodies, lysosomes, and degenerating fat inclusions in hepatocytes and cytomembranes of adipocytes. Glycogen accumulations were found in fat inclusions. It was concluded that CAT played a role in resorption of excessive fat from which intracellular glycogen was formed. The myelin-like membrane structures remaining after utilization of fat from fat inclusions were eliminated from the cells and could penetrate into the adjacent capillaries.