A connection between the production of prostaglandins during liver regeneration and the DNA synthetic response.

The concentration of PGE equivalents in rat liver in vivo was increased during liver regeneration. The probability that this increase reflected a stimulation of prostaglandin synthesis was confirmed in vitro by the ability of homogenates of regenerating liver tissue to synthesize PGE2 and PGF2alpha from arachidonate. Indomethacin prevented these prostaglandin changes, and the subsequent increase in DNA synthesis. The administration of indomethacin to rats was found to induce a hypocalcemia, and to block the hypercalcemic action of parathyroid hormone. It is suggested that the influence of prostaglandins on DNA synthesis involves calcium metabolism.