gms | German Medical Science

83. 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. - 20.05.2012, Mainz

Cell-specific distribution patterns after intratympanic application of gentamicin and doxycyclin within the guinea pig cochlea

Meeting Abstract

  • corresponding author presenting/speaker Ulf-Rüdiger Heinrich - University Medical Center of the Johannes Gutenberg - University Mainz, Mainz, Germany
  • Ilka Fischer - University Medical Center of the Johannes Gutenberg - University Mainz, Mainz, Germany
  • Jürgen Brieger - University Medical Center of the Johannes Gutenberg - University Mainz, Mainz, Germany
  • Wolf-Jürgen Mann - University Medical Center of the Johannes Gutenberg - University Mainz, Mainz, Germany
  • Kai Helling - University Medical Center of the Johannes Gutenberg - University Mainz, Mainz, Germany

German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. 83rd Annual Meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. Mainz, 16.-20.05.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. Doc12hno35

DOI: 10.3205/12hno35, URN: urn:nbn:de:0183-12hno351

Veröffentlicht: 23. Juli 2012

© 2012 Heinrich 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

Introduction:The main reason for inner ear damage might be based on an increase in reactive oxygen and/or nitrogen species. The aim of the present study was to identify those regions within the cochlea where the NO-producing agent gentamicin and the NO-repressing substance doxycyclin become located after intratympanic application.

Methods: Gentamicin or doxycyclin were injected on both sides into the middle ear of male guinea pigs (n = 24 and n = 3, respectively). The cochleae were removed 1, 2 and 7 days after gentamicin injection or 1, 6 and 24 h after doxycyclin application, transferred into fixative and embedded in paraffin. The distribution patterns of gentamicin and doxycyclin were determined by specific antibodies on semi-thin sections. The cellular staining intensities were quantified for seven cochlear regions after the various time points of incubation by computer-assisted programs.

Results: Gentamicin was identified in wide regions of the cochlea in all experimental groups but with cell-specific differences. An intense accumulation was observed within the spiral ligament, in the limbus-area and in hair cells, with the tendency of a decrease from the first to the third cochlea turn. The role of the modiolus and of the lateral wall is discussed in respect to possible routes of infiltration. Doxycyclin was preferentially located in the stria vascularis and in hair cells.

Conclusion: The accumulation of gentamicin identified in those cochlea regions which are responsible for potassium recycling might result in a local NO-increase leading finally to cochlear damage. The specific accumulation of doxycyclin in the stria vascularis and hair cells might prevent an NO up-regulation in stress situations in these areas and offers a promising approach for human medication in future.