[New aspects in the liver regeneration following partial hepatectomy]

We demonstrated the new two concepts for the liver regeneration after partial hepatectomy (PHx). The first is immunological findings in the regenerating liver. Th1 type T cells, which produce IFN gamma, and extrathymic T cells may play an important role in immunological control system of liver regeneration after PHx on the basis of the cellular immunity restricted by MHC class I and II molecules. The second is the mechanism of "on and off" on liver regeneration after PHx. Portal pressure, which reflecting wall shear stress of sinusoid, may trigger the liver regeneration and control the liver volume after PHx. There are two type of intrahepatic leukocytes; one type would tend to stay associated with SEC, while the other would not. Therefore shear stress may have a great influence on the leukocytes-sinusoidal endothelial cells (SEC) adhesion immediately after partial hepatectomy.