Absence of expression of interleukin-6 (IL-6) mRNA in regenerating rat liver

The serum level of IL-6 and expression of IL-6 mRNA in hepatocytes from regenerating liver were investigated in the rat. The IL-6 level in the serum was not significantly different from that of a control group of rats submitted to an acute experimental inflammation. IL-6 mRNA expression did not occur in the liver of hepatectomized rats as judged from Northern blotting experiments using an IL-6 riboprobe. These results suggest that if IL-6 is implicated in hepatic regeneration, this cytokine is not produced by the regenerating liver and must be delivered exogenously to the liver to modulate hepatic regeneration.