Acoustic stimulation promotes the expression of inducible nitric oxide synthase in the vestibule of guinea pigs.
Loud acoustic stimulation is known to cause inner ear disturbance. We examined immunohistochemically the vestibule of 12 guinea pigs after acoustic stimulation. The animals were divided into two equal groups: a control group and an acoustic stimulation group. The temporal bones were fixed by means of a cardiac infusion of fixative and immunohistochemically stained for inducible nitric oxide synthase (iNOS). The temporal bones in the control group did not show any iNOS. In the acoustic stimulation group, immunoreactivity for iNOS was detected in the supporting cells and sensory cells of the sensory epithelium, in the dark cell areas and in the vestibular ganglion cells. These findings suggest that free radicals are involved in the pathogenesis of noise-induced inner ear damage. Furthermore, free radicals may cause vestibular damage, as is seen in noise-induced inner ear damage.
Department of Otorhinolaryngology, Nippon Medical School, Kawasaki, Kanagawa, Japan. bxp02646@nifty.ne.jp
Ken-ichi
K
Watanabe
Shunta
S
Inai
Alexander
A
Hess
Olaf
O
Michel
Toshiaki
T
Yagi
D000161:Acoustic Stimulation / Q000379:methods*; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000201:enzymology; D016022:Case-Control Studies; D005609:Free Radicals; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000201:enzymology / Q000209:etiology*; D006801:Humans; D007150:Immunohistochemistry; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000097:blood; D010610:Pharyngeal Neoplasms / Q000201:enzymology; D014722:Vestibule, Labyrinth / Q000201:enzymology* / Q000502:physiology*
D005609:Free Radicals; D019001:Nitric Oxide Synthase