Is there a regeneration stimulator substance in the effluent from perfused partially hepatectomized livers?

An attempt was made to transfer a stimulator substance from the perfusate of partially hepatectomized perfused livers to the portal stump of portacaval-shunted pig recipients. Blood was either cross-circulated with recipients during perfusion or was given by exchange transfusion after 4 hr perfusion. There was an increase in thymidine kinase activity and mitotic indices in biopsies from portacaval-shunted recipients whether perfusions were performed 2 or 4 days after partial hepatectomy. Blood perfused through intact livers did not enhance the regenerative response of portacaval-shunted pigs; in fact it appeared to suppress the normal small response. Approximately 10% of the portacaval-shunted recipients died acutely when perfusate was infused into the portal stump. This did not occur if saline or unperfused blood was used suggesting that some toxic substance accumulated during liver perfusion. In end-stage fulminant hepatic failure, use of blood perfused through a partially hepatectomized animal liver may provide the regenerative stimulus which often appears to be lacking.