Influence of oxidative stress and alpha tocopherol supplementation on urothelial cells of the urinary bladder in ovariectomised rats

Abstract

The present study was designed to investigate whether vitamin E supplementation would influence the levels of oxidative stress and the damage to urothelial cell DNA in the bladders of castrated rats. A total of 30 rats of the Wistar breed were divided into 3 groups of 10 animals each. Group 1 underwent a sham procedure and was killed after 30 days; group 2 underwent bilateral oophorectomy and was killed after 30 days without receiving vitamin E supplementation and group 3 underwent bilateral oophorectomy and received vitamin E supplementation at a dose of 1,000 IU/kg once a week intra-muscularly for 30 days. Four weeks after the procedure, the rats were anesthetised and their bladders were rapidly removed, frozen and stored at -70 degrees C for Comet assaying, which was carried out on lymphocytes and vesicular urothelium cells. The 8-isoprostane concentration in plasma was also determined to confirm the presence of oxidative stress. The 8-isoprostane levels found were higher in oophorectomised rats that had not received vitamin E supplementation than in the sham group and the oophorectomised group with vitamin replacement. Tail moment analysis on the urothelial cells demonstrated that the oophorectomised group presented DNA damage that was statistically significant in comparison with the other groups. On the basis of the above data, vitamin E decreased the effects of oophorectomy on lipid peroxidation and avoided the DNA damage observed in urothelial cells.