When lymphokine activated killer cells (LAK cell) induced by IL-2 are infused into the same strain C3H mice following 70% partial hepatectomy, they display an action to suppress liver regeneration. Therefore, when Cyclosporin A (CsA) which inhibits IL-2 production was administered to mice following partial hepatectomy, we studied as our indicator the labeling index of hepatic parenchyma cells using Brdu. Our findings showed that proliferation of liver cells at 36 hours following partial hepatectomy was promoted by CsA, and the strongest promotion occuring at a dose of 5mg/kg. Before and after hepatectomy when CsA was administered at 10mg/kg for 3 days, a further strong proliferation increasing effect was observed, and under these conditions at 48 and 60 hours after hepatectomy a significant increase in liver weight was observed. Given the above results, CsA is thought to have a promoting effect in liver regeneration following hepatectomy.
