HEAT-SHOCK PROTEIN-70 IN RAT-LIVER REGENERATION AFTER HEPATECTOMY

Heat shock protein (hsp) is considered to play an important role in protection of the cell structure and a chaperone-like function in intracellular transport. In this paper, the changes in content and distribution of hsp 70, one of the hsps, were studied in the rat liver in the process of liver regeneration after 70% partial hepatectomy. The content of hsp 70 in liver homogenate was determined by the immunoblotting method and the distribution of hsp 70 in liver tissue was studied by the immunoperoxidase method using the anti-hsp 70 antibody. The content of hsp 70 was increased twice in the liver on the third day after partial hepatectomy. At the sixth hour after hepatectomy, hsp 70 was strongly positive in the nuclei of hepatocyte throughout the liver lobule. The expression of hsp 70 in the nuclei of hepatocytes continued up to a month after hepatectomy around the portal tract where the proliferation of hepatocyte is most active. The above results indicate that hsp 70 is produced in the nuclei of hepatocyte on the early stage of liver regeneration after partial hepatectomy. This production of hsp 70 continues for a long time after hepatectomy, especially around the portal tract.