[An experimental study of the role of portal vein blood factors in the regeneration of the liver after partial hepatectomy].

It is generally accepted that the portal venous blood has an important role in hepatic regeneration. However, the actual factor or factors of the portal venous blood have not been fully identified. In this experimental study on dogs, 1) the effect on the amount of hepatic blood flow, 2) the effect of pancreatic hormones, and 3) the effect of amino acids in the portal vein upon hepatic regeneration at 96 hours after 40% hepatectomy were examined by 3H-thymidine labelling indices of hepatocyte nuclei. Diversion of portal blood from the liver resulted in a significant decrease of labelling index. Portacaval transposition did not influence the labelling index regardless of pancreatic venous flow into the liver. On the other hand, the direct infusion of amino acids into the liver via portal vein after portacaval transposition with or without pancreatic venous flow significantly increased the labelling index. However, additional arterialization of portacaval transposition resulted in no significant increase of the labelling index. These results indicate; 1) Adequate amount of blood flow is necessary for hepatic regeneration. 2) Pancreatic venous flow into the liver may not be a major factor in hepatic regeneration. 3) High concentration of amino acids in the portal venous blood is one of the most influential factors in hepatic regeneration. 4) Oxygen concentration in the portal vein may not the factor which effected directly hepatic regeneration.