EFFECT OF INTERFERON-ALPHA(2B) ADMINISTRATION ON RAT-LIVER REGENERATION AFTER PARTIAL-HEPATECTOMY

The purpose of the present study was to delineate the effect of interf eron-alpha(2b) (IFN-alpha(2b)) administration on the liver regenerativ e capacity after partial hepatectomy in rats. The administration of IF N-alpha(2b) simultaneously with partial hepatectomy did not affect hep atic proliferation in a statistically significant manner. When IFN-alp ha(2b) was administered either 2 or 12 hr postoperatively, an inhibiti on of hepatocyte proliferation was observed 24 hr postoperatively, whi le at further time intervals up to 48 hr, DNA synthesis remained simil ar to that observed in the simply partially hepatectomized rats, The e nzyme thymidine kinase (TK), has been implicated in the suppression of proliferation in interferon-treated cell cultures, In all IFN-alpha(2 b)-treated groups of rats, alterations of TK activity were observed wi thout being correlated to the liver regenerative status, Additionally, the administration of the polyamine putrescine in partially hepatecto mized rats treated at the time of surgery with IFN strongly enhanced T K activity, but did not affect DNA biosynthesis, In the above-mentione d in vivo model of controlled cellular proliferation, the administrati on of IFN-alpha(2b) affected the rate of hepatocyte proliferation depe nding on the time of its administration; this effect was not correlate d to the enzymatic activity of TK, as inhibited TK activity is respons ible for the suppressed DNA synthesis in in vitro systems.