Impact of castration with or without alpha-tocopherol supplementation on the urethral sphincter of rats.

OBJECTIVE To analyze the impact of low levels of testosterone induced by orchiectomy and the effect of alpha-tocopherol supplementation on oxidative stress in the urethral sphincter. MATERIALS AND METHODS Forty male Wistar rats weighing 250-300 g were divided into four groups with 10 each: Sham group; Orchiectomy group: bilateral orchiectomy; Orchiectomy-pre-Tocopherol group: bilateral orchiectomy preceded by alpha-tocopherol supplementation for four weeks; Orchiectomy-full-Tocopherol group: bilateral orchiectomy with alpha-tocopherol supplementation for four weeks preceding the procedure and for eight weeks afterwards. At the protocol end, animals were euthanized and had the sphincter analyzed stereologically focusing on collagen and muscle fibers percentage. Oxidative stress levels were determined using 8-epi-PGF2. RESULTS The 8-epi-PGF2 levels were statistically higher (p < 0.0003) in the Orchiectomy group compared to others groups while Sham and Orchiectomy-full-Tocopherol groups presented statistically similar values (p = 0.52). Collagen volumetric densities were significantly lower in Sham and Orchiectomy-full-Tocopherol groups (p < 0.022). Sham group presented statistically greater muscle fiber percent. CONCLUSION Castration caused oxidative stress in the urethral sphincter complex, with increased collagen deposition. Alpha-tocopherol had a protective effect and its supplementation for twelve weeks provided the greatest protection.