Ultrastructural changes in otoconia of osteoporotic rats

Vibert, Dominique; Sans, Alain; Kompis, Martin; Travo, Cécile; Muhlbauer, Roman C; Tschudi, Ingrid; Boukhaddaoui, Hassan; Häusler, Rudolf (2008). Ultrastructural changes in otoconia of osteoporotic rats. Audiology & neuro-otology, 13(5), pp. 293-301. Basel: Karger 10.1159/000124277

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The etiology of benign paroxysmal positional vertigo (BPPV) remains obscure in many cases and women are affected more often than men. A recent prospective study, performed in women >50 years of age suffering from recurrent BPPV, showed associated osteopenia or osteoporosis in a large percentage of these patients. These results suggested the possible relationship between recurrent BPPV and a decreased fixation of calcium in bone in women >50 years. To test this hypothesis, an experimental study was performed in adult female rats. Utricular otoconia of female rats in which osteopenia/osteoporosis was induced by bilateral ovariectomy (OVX) were compared to those of sham-operated adult females rats (SHAM), as control group. FIRST STUDY: The morphology of theutricles of OVX and SHAM rats was analyzed with scanning electron microscopy. In osteopenic/osteoporotic rats, the density of otoconia (i.e. the number of otoconia per unit area) was decreased (p = 0.036)and their size was increased (p = 0.036) compared to the control group. SECOND STUDY: To test the role of calcium turnover in such morphological changes, utricular otoconia of 2 other groups of OVX and SHAM rats, previously injected with calcein subcutaneously, were examined by conventional and epifluorescence microscopy. In epifluorescence microscopy, labeling with calcein showed no significant fluorescence in either group. This finding was interpreted as a lack of external calcium turnover into otoconia of adult female rats. The ultrastructural modifications of otoconia in osteopenic/osteoporotic female adult rats as well as the role of estrogenic receptors in the inner ear are discussed. The possible pathophysiological mechanisms which support the relationship between recurrent BPPV in women and the disturbance of the calcium metabolism of osteopenia/osteoporosis are debated.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Ear, Nose and Throat Disorders (ENT)

UniBE Contributor:

Vibert-Mennet, Dominique and Häusler, Rudolf

ISSN:

1420-3030

ISBN:

18391565

Publisher:

Karger

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 15:04

Last Modified:

06 Dec 2013 13:53

Publisher DOI:

10.1159/000124277

PubMed ID:

18391565

Web of Science ID:

000257477800002

URI:

https://boris.unibe.ch/id/eprint/27741 (FactScience: 110676)

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