Serum from partially hepatectomized rats induces primary hepatocytes to enter s phase: A role for prostaglandins?

Abstract

Serum obtained from partially hepatectomized rats 1, 3 or 24 h after operation was more effective in stimulating DNA synthesis in primary adult rat hepatocytes than serum from sham-operated rats; exposure to the serum for 2h was sufficient to promote growth. Serum from the partially hepatectomized rats contained elevated levels of PGE₂ and PGF_2α; it promoted hepatocytes to release prostaglandins into their culture medium. Growthpromoting effects of the serum and its capacity to elicit prostaglandin release into the culture medium were inhibited by 0*1 mM-indomethacin or 1 mM-aspirin. 0–1 mM-indomethacin also prevented DNA synthesis if the inhibitor were added 4h after growth had been initiated by serum from partially hepatectomized rats, suggesting that prostaglandins continue to be important for the maintenance of hepatocyte growth for at least 6h.