Ne, C and He ion beam irradiations have different effects on the expression of glutathione peroxidase in cultured human retinal vascular endothelial cells exposed to L-dopa

Akeo, Kiyoshi*; Hamada, Nobuyuki*; Funayama, Tomoo; Akeo, Yoko*; Kobayashi, Yasuhiko

We investigate how L-dopa influences glutathione peroxidase (GPX) in preventing damage to membrane phopholipids of retinal endothelial cells (RE). Human RE incubated in vitro with 250 M L-dopa were exposed to heavy ion beams of 350 MeV Ne, 220 MeV C, and 50 MeV He. We collected RE after 0, 4, 8, 24 hrs of irradiation, extracted total cellular RNA, and synthesized cDNA, then the expression of GPX and 18S RNA were measured by realtime RT-PCR using specifically designed primers. The exposure to L-dopa inhibited the expression of GPX in RE. The expression of GPX in RE incubated with L-dopa decreased significantly after exposure to He and C. In contrast, Ne- ion beam irradiation significantly increased the expression of GPX in RE incubated with L-dopa. The result indicated that the difference of LET of ion species resulted to the different expression GPX in RE incubated with L-dopa.