Objective To observe the effect of exogenous basic fibrob last growth factor (bFGF) on apoptosis of cultured human retinal pigment epithelial (RPE) cells exposed to visible light,and determine the role of bFGF, fibroblast growth factor receptor 1 (FGFR1),bcl-2 and caspase-3. Methods 2000±500) lx cold white light was used. Exogenous bFGF was utilized during culture. Annexin annexin V-fluoresce in isothiocyanate/propidium iodium (V-FITC/PI) labeling,flow cytometry, Immunocytochemical staining, enzyme associated absorb examing and reverse transcriptional polymerase chain reaction (RT-PCR) were used to determine the apoptosis, the expression levels of bFGF, FGFR1, bcl-2, as well as the activity of caspase-3. Results No protective effect of bFGF was observed under the concentration 5 ng/ml.A significant inhibition of apoptosis was found in 10 ng/ml and 20 ng/ml groups （P＜0.05）. The upregulation of bcl-2 was observed in bFGF (10 ng/ml, 20 ng/ml) protreated groups（P＜0.01）.Compared to no light exposure group,all light exposure groups (including bFGF pro-treated) had higher endogenous bFGF and FGFR1 levels （P ＜0.05）, and the increase was concentration dependent.The bFGF and FGFR1 levels were higher in exogenous bFGF applied (gt;5 ng/ml) groups than light exposure groups（P＜0.05）. The caspase-3 activity was significantly inhibited in bFGF (10 ng/ml) pro-treated groups. Conclusions Human RPE cells exposed to visible light were rescued by application of exogenous bFGF in vitro.The probable protective mechanism of bFGF partly is directly binding to FGFR1 or potentiating endogenous bFGF autocrine loop,to upregulate bcl-2 and to inhibit caspase-3 activation. (Chin J Ocul Fundus Dis，2003，19：24-28)
Objective To observe the effect of visible light on apoptosis of cultured human retinal pigment epithelium (RPE) cells. Methods Being the light source,500lx,(2 000±500)lx and (3 400±200)lx cold white light were used. The duration of exposure was 0,6,12 and 24 hours respectively. Apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling, Annexin V-flunorescein isothiocyanate/Propidium iodium labelling and flow cytometry. Results Apoptosis and necrosis were found in cultured human RPE cells which were exposed to visible light.(1)A significant increase in apoptotic and necrotic percentages was consistent with a higher light intensity.(2)Apoptosis was the main response to shorter (6 h and 12 h) exposure duration,while necrosis was more pronounced correlated to the prolongation of post-exposure culture (P＜0.05),and the longer the post-exposure period was, the more apoptotic necrosis were seen.Thirty-six hours after exposure the necrotic percentages were more pronounced (P＜0.01). Conclusions Visible light (＞500 lx) increases the proportion of apoptosis and necrosis of human RPE cells in vitro.The extent is related to exposure intensity and duration. It demonstrates that the lower intensity and the shorter duration of exposure to light are, the more pronounced apoptotic percentages are observed,otherwise necrosis. (Chin J Ocul Fundus Dis, 2002, 18: 227-230)