gms | German Medical Science

77. 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.

24.05. - 28.05.2006, Mannheim

Functional and morphological characterization of diabetic otopathy in Zucker diabetic fatty rats

Meeting Abstract

German Society of Otorhinolaryngology, Head and Neck Surgery. 77th Annual Meeting of the German Society of Otorhinolaryngology, Head and Neck Surgery. Mannheim, 24.-28.05.2006. Düsseldorf, Köln: German Medical Science; 2006. Doc06hno035

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Veröffentlicht: 7. September 2006

© 2006 Meyer zum Gottesberge et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Epidemiological data indicate an excess incidence of sensorineural hearing loss in patients with diabetes mellitus. However, the pathophysiological background of this diabetic otopathy remains unclear. We investigated hearing function (AEPs) and inner ear morphology (electron microscopy) and in parallel kidney function and morphology in the Zucker diabetic fatty (ZDF) rat, a type 2 diabetic animal model. Homozygous (ZDF fa/fa, n=8), diabetic animals had developed overt diabetes mellitus (HbA1c > 10 % by age 15 weeks) and progressive albuminuria (24.4+/-4.9 mg/h/kg at age 42 weeks), whereas heterozygous, non-diabetic littermates (n=9) remained normoglycaemic and did not develop albuminuria. At age 42 weeks, the hearing threshold was increased in the diabetic animals to 45.0+/-2.1 dB, compared to 34.7+/-1.0 in non-diabetic rats (p<0.05). Diabetic nephropathy and otopathy developed in parallel, as reflected by the linear correlation between albuminuria and hearing threshold in the diabetic animals (r=0.65, p<0.05). Histological and electron microscopic analysis demonstrated all typical features of diabetic nephropathy in the homozygous rats (glomerulosclerosis, podocyte damage, and tubular degeneration). Morphological analysis of the inner ear did not reveal microvascular injury. However, severe degenerative damage was found in the intermediate cells of the stria vascularis. Conclusion: Type 2 diabetes mellitus is associated with functional and morphological damage to the inner ear, which occurs in parallel to typical end organ damage, such as diabetic nephropathy. In contrast to the microvascular injury in nephropathy, diabetic otopathy is characterized by a specific damage to the intermediate cells of the stria vascularis.