Expression of Caspase-3 in Cochlea of White and Pigmented Guinea Pigs Exposed to Impulsive Noise

Objective To observe the expression of Caspase-3 in the cochlea of white and pigmented guinea pigs exposed to impulsive noise,and to explore the protective mechanism of melanin on cochlea damage.Methods Eight white guinea pigs and eight pigmented guinea pigs were exposed to impulsive noise to induce cochlea damage.Then the injured cochlea from the guinea pigs were embedded with paraffin,and cut into slides.The expression of Caspase-3 in the cochlea was examined by the method of immunohistochemistry.Results The expression of Caspase-3 in the cochlea of two kinds of guinea pigs was positive.Caspase-3 expression was much stronger in the area of stria vascularis and spiral ganglion cell,and was much stronger in the white guinea pigs than that in the pigmented guinea pigs.Conclusion The therapeutic mechanism of melanin in counteracting the cochlea damage may be related with the inhibition of cochlea cell apoptosis through inhibiting Caspsae-3 activity in the cochlea.