Evaluation of the protective role of selenium against lead toxicity on the cortex of cerebrum and cerebellum of albino rat. histological study

ABSTRACT

The danger of lead in the environment on the public health continues to be a matter of concern. Children are more vulnerable to lead toxicity, which is associated with deficits in central nervous system functions. This study was done to evaluate he protective role of selenium against lead toxicity on the motor cerebral cortex as well as cerebellar cortex in albino rats exposed to lead during young age. Twenty young albino rats -aging one month- were used in this study. They were classified into 4 equal groups 5 rats each. Group I was the control group, Group II included animals, which received selenium; Group III included animals, which received lead acetate and Group IV included animals, which received lead acetate and selenium concomitantly. Twenty four hours after the last dose, the animals were decapitated. The brain and cerebellum were dissected out and prepared for histological study. In-group III there was focal areas in the motor cerebral cortex where the cortical layers were almost disorganized. The affected pyramidal cells appeared shrunken with fragmentation of their Golgi complex. In the cerebellar cortex, lead acetate administration preferentially affected the purkinje cells. The cytoplasm of both pyramidal and purkinje cells showed marked decrease of Nissl's material with apparent reduction in their mitochondrial content. Concomitant administration of selenium with lead acetate showed marked protection to both cerebral and cerebellar cortices structure which appeared more or less similar to the control group