Deltamethrin induces mitochondrial membrane permeability and altered expression of cytochrome C in rat brain

Deltamethrin is a type 11 synthetic pyrethroid insecticide and is used extensively. Numerous studies have demonstrated that deltamethrin can cause severe central nervous system symptoms. The mechanism of neurotoxicity caused by deltamethrin is still poorly understood. This study investigated the effect of deltamethrin on the mitochondria-mediated apoptosis pathway in rat brain. The cortex and hippocampus mitochondrial membrane potential, permeability transition, expression of cytochrome c and activity of cytochrome c oxidase was assayed at 5, 24, 48 and 72 h following deltamethrin treatment. The study observed that the membrane potential, change of absorbance at 540 nm (A(540)), intensities of cytochrome c in mitochondria and activity of cytochrome c oxidase in the cortex and hippocampus of treated groups were significantly lower than those of the control group. The results of the study demonstrated that deltamethrin induced a decreased mitochondrial membrane potential and increased permeability, and reduced the expression of cytochrome c, thus depressing the activity of cytochrome c oxidase significantly. It indicates that deltamethrin may have an effect on mitochondria-mediated apoptosis of nerve cells in the rat brain. Copyright (C) 2007 John Wiley & Sons, Ltd.