RESUMO
PURPOSE: To analyze the influence of α-tocopherol supplementation on the levels of oxidative stress and apoptosis rates in the anal sphincter induced by orchiectomy in rats. METHODS: Forty male Wistar rats weighing 250-300 g, were divided into four groups and sacrificed 8 weeks after: I- Control: sham; II- Orchiectomy: bilateral orchiectomy; III- Pre Orchiectomy Tocopherol: α-tocopherol supplementation for 4 weeks preceding bilateral orchiectomy; IV- Orchiectomy Full Tocopherol: α-tocopherol supplementation for 4 weeks before and 8 weeks after bilateral orchiectomy. The anal sphincter was analyzed stereologically to evaluate the density of collagen and the muscle fibers. The oxidative stress and the apoptosis were determined with 8-isprostane and caspase-3, respectively. RESULTS: The collagen fibers concentration was statistically greater in Orchiectomy group than the others. The muscle fibers concentration was higher in Control and Orchiectomy Full Tocopherol than Orchiectomy and Pre Orchiectomy Tocopherol groups. Orchiectomy group showed higher 8-isoprostane concentrations compared to the other groups (p < 0.0003). Pre Orchiectomy Tocopherol and Orchiectomy Full Tocopherol groups presented caspase-3 levels lower than the Orchiectomy group (0.0072). CONCLUSION: Vitamin supplementation with α-tocopherol for 12 weeks had the highest protection against bilateral orchiectomy generation of reactive oxygen species as well as apoptosis in the muscle fibers of the anal sphincter of rats.