EXPRESSION OF NITRIC OXIDE SYNTHASE IN COCHLEA OF GUINEA PIG

Objective: To investigate nitric oxide synthase (NOS) expression in cochlea of guinea pig, and define the effect of NO as neurotransmitter and endothelium derived relaxing factor (EDRF) in auditory physiology and pathophysiology of inner ear diseases. Methods: Thirty five white red eyes guinea pigs were used, and expression of NOS in cochlea of guinea pig was studied with NADPH diaphorase histochemistry and in situ hybridization technology. Results: NOS mainly distributed in inner hair cell (IHC), outer hair cell (OHC) of Corti's organ, the cells of spiral ganglion (SG) and the marginal cells of stria vascularis (SV) in the guinea pig cochlea. The NOS in the IHC, OHC and spiral ganglion cell was different from the NOS in the marginal cells of SV. It submitted to brain NOS or endothelium NOS. Conclusion: Expression of NOS in cochlea was detected. It showed NO was neurotransmitter or modulator in cochlea afferent and joined self regulation of microcirculation of the cochlea.