gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

Influence of Hydroxyl radicals on the Ca2+-metabolism of the retinal pigment epithelium

Meeting Abstract

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  • corresponding author L. Schlichting - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Hamburg-Eppendorf
  • O. Strauß - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Hamburg-Eppendorf
  • O. Zeitz - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Hamburg-Eppendorf

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogP 128

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Veröffentlicht: 22. September 2004

© 2004 Schlichting 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

Objective

An increased oxidative exposure of the retinal pigment epithelium (RPE) plays an important role in the genesis of age-related macular degeneration (AMD). A major damaging factor could be the disturbance of the Ca2+-homeostasis, subsequently leading to functional changes and apoptosis. This work uses cultured RPE-cells to investigate the effect of Hydroxyl radicals on the Ca2+-homeostasis.

Methods

All experiments were performed using the human RPE cell line ARPE-19. The intracellular Ca2+-content was determined by implementing the Fura 2 method. The ratio between the fluorescence intensities of 340 and 380nm is correlated to the Ca2+-concentration. The cells were incubated for 2 minutes with Hydroxyl radicals that were created via the Fenton reaction using H2O2 and Fe3+ and continuously observed for 60 minutes. The survival rate of the RPE cells is determined by using the Life-Dead-Assay from MoBiTec (Göttingen, Germany).

Results

Immediately after radical exposure the ARPE-19 cells showed a steep transient Ca2+-increase. Afterwards the Ca2+-concentration decreased but stabilized at a permanently elevated value well above the baseline. A progressive death rate of RPE cells could be detected with the Life-Dead-Assay between 1 to 6 hours after radical exposure. Addition of 10mM Ascorbic acid inhibited the increase of the radical induced intracellular Ca2+-concentration.

Conclusions

Oxidative exposure of cultured RPE cells leads to an intracellular Ca2+ overload. The delayed cell death after radical exposure is rather caused by a selective damage to the Ca2+-homeostasis then by some unspecified destruction of the cell membrane. Changes in intracellular Ca2+-levels could lead to cellular dysfunctions because Ca2+ is a strong apoptosis factor as well as an important second messenger.