Cyclosporin A stimulates proliferation of the liver cells after partial hepatectomy in rats.

The effects of cyclosporin A (CyA) upon regeneration of the liver were studied in rats after partial hepatectomy. In group 1, a standard two-thirds hepatectomy was performed. In group 2, CyA, a dose of 10 milligrams per kilogram, was given orally one day prior to, on the day of the operation and 24 hours after hepatectomy. The liver weight restoration, histologic findings and mitotic activities of remnant livers and serum levels of aminotransferase, albumin, total bilirubin and creatinine values were examined from 24 hours to ten days after the operation. Treatment with CyA resulted in an increase of the mitotic activities of the hepatocytes, which were twice as high as those in the control group. This phenomenon coincided well with the regenerative rate of remnant livers, histologic factors, albumin synthesis and other biochemical parameters. Our results indicate that CyA has a stimulatory effect upon liver cell proliferation after partial hepatectomy in rats. The augmentative effect of CyA on liver regeneration is discussed.