RESUMEN
Doxorubicin (DXR) is a widely used chemotherapeutic anticancer agent that has potent activity against several solid and non-solid human malignant tumors, including childhood malignancies. However, DXR has serious toxic effects on tissues with rapid cell cycles, such as myeloid and lymphatic tissues, intestinal mucosa, testes and ovaries. In the present study, the short- and medium-term toxic effects of DXR on the reproductive system of male Wistar rats were evaluated using morphometric and stereological tools to quantify damage to the seminiferous epithelium. Adult male Wistar rats were treated with dose of 7.5â¯mg/kg of DXR and were sacrificed at seven, 14, 21 and 28â¯days after treatment. The testes were fixed in glutaraldehyde solution, routinely processed and embedded in plastic for evaluation under a light microscope. A significant reduction in testis weight was found as a result of massive germ cell apoptosis. Differences in comparison to the control group were found in the relative frequency of all stages of the seminiferous epithelium cycle, with significant differences for stages VIII-XI. Apoptosis significantly decreased the number of pachytene spermatocytes in the stages evaluated (I, II-III and VIII) at seven and 14â¯days. At 21 and 28â¯days after treatment, the testes exhibited the massive loss of germ cells that resulted in a missing cell layer. Moreover, reductions in the height of seminiferous tubules, tubular diameter and tubular compartment as well as an increase in the intertubular compartment were found in the period studied.