97th DOG Annual Meeting 1999
INFLUENCE OF RADIATION ON HUMAN RPE CELLS IN VITRO
L. Kohen, V. Enzmann, A. Petzold, J. Jahns, F. H. Kamprad,
Cytokines secreted by RPE cells influence the neovascularisation in AMD. Therefore, RPE cells play an important role in the pathophysiology and therapy of this disease. Currently the efficacy of radiation is discussed. We evaluated the influence of radiation on the secretion of cytokines on human RPE cells in vitro.
Material and methods: Non confluent human RPE cells were radiated in 4 sessions with 2, 4, 8 and 16 Gy on 4 consecutive days with a Cobalt-60 unit. TGFß2, bFGF, and EGF were measured with the ELISA technique on the first, third and seventh day after the radiation exposure. The cells were also counted with a trypan-blue exclusion test.
Results: Depending on the radiation dose an increase of TGFß2 concentration was measured. A similar effect was observed for bFGF. EGF could not be measured in the radiated groups and the unradiated control. The survival of the cells decreased inverse to the radiation dose. On the seventh day after radiation the cell number decreased with a 64 Gy dose to 11.3% in comparison to the unexposed control.
Conclusions: Radiation of RPE influences the secretion of cytokines. In AMD the endothelial cells of the new vessels are not the only influenced cells by radiation. The changes in the secretion of cytokines by RPE cells due to the radiation will influence the therapeutic effect.
Department of Ophthalmology, University of Leipzig, Liebigstr. 10-14,