Hepatocyte transplantation into the lung for treatment of acute hepatic failure in the rat. The lung was investigated as a matrix for transplanted hepatocytes in the rat model. Surgically induced fulminant hepatic failure was successfully treated by injection of 5 to 7 x 10(7) isolated hepatocytes into the pulmonary parenchyma in 86% of the animals. No animal, however, survived injection of hepatocytes into the jugular vein. It was found that liver failure is a prerequisite for the intrapulmonary survival of hepatocytes. After regeneration of the native liver, the majority of hepatocytes are cleared away within 6 months. 