Oxidative stress induced by fluoride in adult mice and their suckling pups.

To assess renal and liver damages in pregnant and lactating mice as well as in their suckling pups, Wistar female mice were given 500 ppm NaF (226 ppm F-) in drinking water from the 15th day of pregnancy until day 14 after delivery. All mice were sacrificed on day 14 after parturition. In the present work, we evaluated the effects of sodium fluoride on histopathological aspects of kidney, antioxidant status, lipid peroxidation levels and on the expression of four stress proteins (namely, the cytosolic heat shock proteins: HSP72, 73, 90 and the reticulum-associated GRP94). Histological studies have shown many abnormalities in mothers and their pups. Biochemical results showed that lipid peroxidation increased in NaF-treated mice, as evidenced by high kidney and liver thiobarbituric acid reactive substance (TBARS) levels. Alteration of the antioxidant system was confirmed by the significant decline of serum total antioxidant status and of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in red blood cells. Besides, fluoride treatment induced a decrease in serum levels of non-enzymatic antioxidants such as uric acid and of some oligoelements: zinc and copper, known to be cofactors of superoxide dismutase (SOD-Cu-Zn). Compared to control group, the 72kDa protein was found to be overexpressed in kidney of 14-day-old mice only. HSP90 expression in liver appeared moderately inhibited in mothers, but decreased significantly in their pups. No significant changes were detected in the expression of 94kDa protein in both liver and kidney. Results showed that fluoride given to dams led to an oxidative stress in mothers as well as in offspring able to induce enhanced lipid peroxidation levels and protein conformational changes, as suggested by stress protein (HSP, GRP) expression changes.