[Electron microscopic and radioautographic study of DNA synthesis in kidney tubule epithelial cells in white rats with sublimate-induced necronephrosis].

Electron microscopic analysis of 3H-thymidine radioautographs of ultrathin sections from the white rat kidney has revealed that 72 hours after subcutaneous injection of 0.5 mg per 100 g body weight of mercury bichloride, the damaged and partially necrotized epithelial cell became capable of DNA synthesis. However, due to the reduction of cellular organelle count the process was less intensive, as compared to that in insignificantly damaged cells. The presence in the cytoplasm of many damaged epithelial cells capable of DNA synthesis and free ribosomes demonstrates that the RNA and free ribosome biogenesis is an earlier cell regenerative reaction than DNA synthesis.