Ultrastructural alterations and DNA synthesis of renal cell nuclei following cisplatin or carboplatin injection in rats.

To clarify the difference in nephrotoxicity between cisplatin and carboplatin, ultrastructural alterations and DNA synthesis of renal cell nuclei were studied in Sprague-Dawley rats which had received intravenously either cisplatin or carboplatin at an equitoxic dose. Twelve hours after cisplatin injection, nucleolar segregation accompanied by aggregated nuclear heterochromatin was observed in the third segment of the proximal tubules. Seventy-two hours after cisplatin injection, nuclear damage was more widespread while regenerative cells were also observed. Nuclear damage was not observed in the carboplatin-treated rats. Nuclear DNA synthesis of renal cells was suppressed at 8, 12 and 24 h and was accelerated at 72 h after cisplatin injection. Carboplatin did not suppress nuclear DNA synthesis at any time. The results indicate that cisplatin, but not carboplatin, can affect the renal cell nuclei. Cisplatin-induced nephrotoxicity is related to its effects on renal cell nuclei.