Toxicity of Highdoses of Copper, Zinc And Vitamin D in Rats’ Brain

Abstract

Aims: The aim of this study was to determine the toxicity of the copper sulfate, zinc sulfate and vitamin D3 for two periods (45 days and 90 days) on brain of rats. Methods: Dixon's method was used for the estimation of median lethal doses (LD50). Survival and mortality number for each dose have been noted after 24 hours. Following the determination of the median lethal doses (which were 637 mg/kg. 2.4 g/kg and 13.74 mg/kg b. w. for copper sulfate, zinc sulfate and vitamin D3 respectively) seventy rats were divided into seven groups and housed in same environment cages. The seven treatment groups were divided into group I (the control group) while group II, III, IV, V, VI and VII were subdivided depending on the dosing regimen, the rats in the second group (Group II) (receiving copper sulfate 1/10 LD50), third group (Group III) (receiving copper sulfate 1/20 LD50), forth group (Group IV) (receiving zinc sulfate 1/10 LD50), fifth group (Group V) (receiving zinc sulfate 1/20 LD50), sixth group (Group VI) (receiving vitamin D3 1/10 LD50), and finally, seventh group (Group VII) (receiving vitamin D3 1/20 LD50). Results: Histopathological examination of brain tissue in group II & group III showed congestion of small blood vessels (B.V.). The brain tissues in group IV and group V showed congestion of small B.V. with edema. Group VI and group VII shows aggregation of mononuclear cells in small foci in the brain. Copper-induced toxicity (1/20 of LD 50) changes in the brain were less pronounced in rats treated with copper (1/10 of LD 50), the case similar in groups that treated with zinc or vitamin D, compared to rats of control group. Conclusion: In the present investigation the vitamin D3 has been found to be more toxic than copper sulfate or zinc sulfate based on the median lethal doses (LD50) values. This study shows that both these trace heavy metals (copper sulfate and zinc sulfate) along with vitamin D3 can be toxic to organisms at higher levels. Keywords: Heavy metal salts, brain, female rat