[The effect of noise exposure on the expression of NOSmRNA in the cochlea].

OBJECTIVE

To study the effect of NO in noise-induced deafness.

METHOD: The effect of noise exposure on the expression of NOSmRNA in the guinea pig cochlea was observed with NADPH-diaphorase histochemistry staining, NOSmRNA hybridization in situ and Northern blotting analysis.

RESULT: NADPH-diaphorase histochemistry indicated that NOS mainly presents in the inner hair cells, outer hair cells of Corti's organ, spiral ganglion cells and the marginal cells of stria vascularis in the guinea pig cochlea; NOSmRNA hybridization in situ showed that there is positive signal in the inner hair cells, outer hair cells and spiral ganglion cells, but there is no positive signal in the stria marginal cells of vascularis; Northern blotting showed that the expression of noise exposure group is more intensive than that of the control group.

CONCLUSION

There is a Glu: NMDA receptor, NO: cGMP pathway in the cochlear afferent possibly; noise exposure induced overproduction of NO mediates the effect of neurotoxicity; the marginal cells of stria vascular produce and release NO to regulate the microcirculation of the cochlea.