Pathogenesis of vacuolar degeneration of the hepatocyte

Significance of intrasinusoidal pressure elevation

Abstract

It is generally believed that the hepatocytes are extremely vulnerable to hypoxia, and that vacuolar degeneration of the hepatocyte is the earliest light microscopic change in hypoxia. To analyse the pathogenesis of the vacuolar degeneration, the present study was carried out by isolated liver perfusion experiments. In severe hypoxia, a decrease in hepatic function was recognized, but no vacuolar degeneration developed at all. In hyperoxia, vacuolar degeneration appeared in the hepatocytes of the central zone at a inferior vena cava pressure of 60-70mm H₂O, and also developed in the hepatocytes of the peripheral zone with the higher pressure. Moreover, vacuolar degeneration appeared in the hepatocytes of the peripheral zone at a portal vein pressure of 160mm H₂O. It was concluded that the development of vacuolar degeneration of the hepatocyte is closely related with the increase in the intrasinsoidal pressure and not with hypoxia. As for the reason why the vacuolar degeneration generally appear in the hepatocytes of the central zone, we would suggest the hypothesis that the critical sinusoidal pressure for vacuole formation of the hepatocytes of the central zone is lower than that of the hepatocytes of the peripheral zone.