Induction of DNA replication and cell growth in rat liver by obstructive jaundice

Obstructive jaundice, produced by ligating the common bile duct, induced a transient DNA replication followed by cell proliferation in rat liver. At 48 h after the operation, DNA polymerase alpha activity started to increase and reached its maximum level (more than twice the control) at day 4. At day 7, the enzyme level had decreased to the control level. Pulse-labeling experiment using radioactive thymidine showed that the rate of DNA synthesis increased approximately 2.5-fold in the same pattern as that of DNA polymerase alpha. The mitotic index in hepatocytes also increased 10-fold at day 4 and then decreased. The proliferation of liver cells induced by obstructive jaundice mimics the regeneration of partially hepatectomized liver, although the response was slightly delayed and the proliferation was transient.