MORPHOMETRIC AND TRIDIMENSIONAL STUDIES OF TUBULAR CYSTIC DEGENERATION IN RAT-KIDNEY FOLLOWING EXPOSURE TO CISPLATIN

Cisplatin, a widely used chemotherapeutic agent, is characterized by a dose-limiting renal toxicity. Cystic tubular dilatation is the most t ypical histopathological alteration encountered in cisplatin-treated r ats. The purpose of the present study was to explore by a morphometric approach the development of cystic degeneration and, in particular, t o analyse, by computer-assisted tridimensional reconstructions, the sp atial structure and the tubular origin of cisplatin-induced renal cyst s. This study was performed on rats given 8 mg/kg cisplatin i.p. for f our days and sacrificed 4, 7, 14, 21, 50 and 60 days after last drug a dministration. The relative area oocupied by cystic tubules increased rapidly in the outer stripe of outer medulla (OSOM) and reached a maxi mum 21 days after the end of treatment. Cystic dilatations appeared la ter in the kidney cortex and the inner stripe of outer medulla (ISOM). The tridimensional study of cystic tubules located in OSOM confirmed previous reports indicating that they arise from proximal straight tub ules and showed that cystic degeneration was not associated with atrop hy or degeneration in more proximal parts of the nephron. Moreover, cy stic tubules located in ISOM were found to originate from distal strai ght tubules and/or the loop of Henle, an observation which, to our kno wledge, has not been reported so far in cisplatin-treated rats.