gms | German Medical Science

78. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

16.05. - 20.05.2007, München

Vitamin C influences NO-production in the inner ear in noise-exposed guinea pigs

Meeting Abstract

German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. 78th Annual Meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. Munich, 16.-20.05.2007. Düsseldorf, Köln: German Medical Science; 2007. Doc07hno033

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Veröffentlicht: 8. August 2007

© 2007 Fischer et al.
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Gliederung

Text

Introduction: Noise induced hearing loss can be induced by an increased NO production in the inner ear leading to oxidative stress and cell destruction. Recently, the degree of hearing loss could be reduced in an animal model by Vitamin C application. To identify the effect of vitamin C application on NO production, we determined the local NO content in organ of Corti and lateral wall 6 h after noise exposure.

Materials and methods: During a period of seven days, male guinea pigs were supplied with minimum (5 mg/animal/day) and maximum (105 mg/animal/day) vitamin C doses and exposed to noise (90dB SPL, 1h). The acoustic evoked potentials (AEPs) were recorded before and after noise exposure. The organ of Corti and the lateral wall were incubated separately for six hours in cell culture medium and the degree of NO production was determined by chemiluminescence.

Results: Vitamin C uptake resulted in a reduced hearing threshold shift with and without noise exposure depending primarily on the degree of the supplied concentration. The NO production was significantly increased in the lateral wall at low levels of vitamin C application but only marginally altered at high vitamin C doses. The NO content in the organ of Corti was only tendentiously increased after low vitamin C concentrations and remained roughly comparable with untreated control specimens at high vitamin C doses.

Discussion: Oral application of vitamin C can be used as natural radical scavenger to reduce the NO-production rate in the inner ear after noise exposure.