gms | German Medical Science

93. Jahrestagung der Vereinigung Südwestdeutscher Hals-Nasen-Ohrenärzte

17. - 19.09.2009, Neu-Ulm

The influence of cholesterol on the motility of cochlear outer hair cells and the motor protein prestin

Der Einfluss von Cholesterin auf die Motilität äußerer cochleärer Haarzellen und das Motorprotein Prestin

Vortrag

  • corresponding author presenting/speaker Martin Canis - Universität München, München, Germany
  • Johannes Schmidt - Universität München, München, Germany
  • Michael Strupp - Universität München, München, Germany
  • Klaus Jahn - Universität München, München, Germany
  • Markus Suckfüll - Universität München, München, Germany

Vereinigung Südwestdeutscher Hals-Nasen-Ohrenärzte. 93. Jahrestagung der Vereinigung Südwestdeutscher Hals-Nasen-Ohrenärzte. Neu-Ulm, 17.-19.09.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09hnosw07

DOI: 10.3205/09hnosw07, URN: urn:nbn:de:0183-09hnosw070

Veröffentlicht: 10. September 2009

© 2009 Canis 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 vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objectives: Elevated serum cholesterol is linked to inner ear disorders and may influence hearing by altering membrane properties of outer hair cells (OHC) and by affecting the motor protein prestin. In this study we wanted to answer the question, if cholesterol modulates electromotility of OHCs and if this modulation results from effects on the membrane properties or on the motor protein prestin.

Method: The motile responses of 12 isolated OHCs were investigated at increasing concentrations of 0, 0.1 and 1 mM extracellular cholesterol using the patch clamp technique and continuous video image analysis. To study effects on prestin, experiments were performed at 12 cells with half activated protein function and concentrations of 0 and 1 mM cholesterol.

Results: Cholesterol at a concentration of 0.1 mM had no effects on motility. 1 mM reduced maximal evoked shortening significantly by 29% in the depolarizing and by 9% in the hyperpolarizing direction. Investigating half activated motor proteins, 1 mM cholesterol reduced movements significantly by 18%, elongations decreased not significantly by 5%.

Conclusions: We provide evidence that cholesterol reduces electromotility in a dose-dependent matter. The data show that cholesterol modulates electromotility mainly by influencing the motor protein prestin, less by affecting the passive membrane properties.