Liver function in regenerating rat liver. CrPO₄ colloid uptake and bile flow

¹ U. S. Naval Radiological Defense Laboratory, San Francisco, California

Functional changes in the regenerating hepatic tissue as indicated by CrPO₄ colloid extraction and bile secretion by the isolated rat liver preparation were studied. Following partial hepatectomy, the liver weight/body weight ratio of the operated rats is significantly lower than the nonoperated controls. This is attributed to only a 80–85% restoration of the residual hepatic tissue. A transient increase in bile secretion/ unit weight of liver by 50% above the preoperative level occurs within 48 hours after partial resection. The uptake of radioactive chromic phosphate colloid indicates an increase in Kupffer cell activity (phagocytic functions) to values 200% above control within 48 hours. This function, however, is sustained and remains elevated for at least 90–100 days postoperatively. Histological evidence indicates that the increased Kupffer cell activity is probably due to an increase in cell population of phagocytic cells. Theoretical considerations for these changes in specific function of regenerating hepatic tissue and their relation to normal resting liver are discussed.