Repair of radiation damage in noncycling parenchymal hepatocytes.

The purpose of this study was to determine whether parenchymal hepatocytes in G0 are able to repair potentially lethal damage. The survival curve for hepatocytes assayed immediately after X irradiation was found to have an extrapolation number, n, which was not significantly different from unit, and a D0 equal to 2.7 Gy. In contrast, when irradiated hepatocytes were allowed to remain in situ for 24 h before being assayed for their reproductive survival , the n value significantly increased to 2.3, whereas the D0 value remains unchanged. But parenchymal hepatocytes are able to repair potentially lethal damage and it is expressed exclusively as an increase in the extrapolation number.