Effect of long term fluoride toxicity on immunity and pathology in Wistar albino rat

Abstract

The aim of the present study was to assess the effect of fluoride toxicity on immunity and pathology of tissues in Wistar rats. Forty eight male Wistar albino rats aged 8 to 12 weeks were divided into four groups of twelve rats each. The group A, B, C and D were given normal water, 10 ppm, 30 ppm and 60 ppm of fluoride (Sodium fluoride), respectively daily in drinking water. At three, six and nine months of inducing fluoride toxicity, rats were injected with sheep red blood cells. Blood was collected after 14 days of injecting sheep red blood cells to assess humoral immunity. At nine months heparinised blood was used to assess cell mediated immunity. At three, six and nine months, rats were sacrificed and tissues collected for pathological study. Group D showed significant (P<0.05) decrease in haemagglutination titre at three months and no significant difference at six and nine months when compared to other groups. Significant (P<0.05) decrease in cell mediated immunity in rats of group D was observed. Effect of fluoride toxicity were observed in liver with vacuolar degeneration and hepatocellular necrosis, in kidney with casts in tubules and in spleen depletion of lymphocytes, in thyroid loss of colloid with degeneration of secretory epithelial cells and in thymus loss of lymphocytes and plasma cells. Histopathological changes in thymus and spleen concurred with immunological changes. Conclusively, fluoride toxicity induced by 60 ppm had effect on humoral and cell mediated immunity, and pathological changes in liver, kidney, spleen, thyroid and thymus in Wistar albino rat.