Deltamethrin induces altered expression of P53, Bax and Bcl-2 in rat brain

In this study we investigated the effects of deltamethrin on the expression of P53, Bax and Bcl-2 in rat brain. Immunohistochemical analysis demonstrated that the immunoreactivity for P53 was markedly increased in the cerebral cortex and hippocampus at 5 h after deltamethrin treatment, and maintained at an increased level at 24 and 48 h, whereas little immunoreactivity for P53 was seen in the same brain regions of control rats. The immunostaining for Bax was also elevated in the same brain regions, showing the same time course of P53 expression after deltamethrin treatment. However, the immunolabeling for Bcl-2 was markedly decreased at 24 h after a transient increase at 5 h following deltamethrin treatment. These results indicate that deltamethrin leads to the persistent increase of P53 and Bax expression and transient elevation of Bcl-2 expression, resulting in an increased ratio of Bax to Bcl-2, which may contribute to apoptotic cell death in rat brain following deltamethrin treatment.