Keywords:calcium wave;confocal;imaging;hypericin;reti-nal pigment epithelial cells

    Abstract:AIM To investigate the mechanism of the Ca2+ signaling in cultured human retinal pigment epithelial(RPE)cells with the protein kinase C(PKC)specific inhibitor-hy-pericin stimulation.METHODS Cultured human RPE cells were analyzed using the fluorescence Ca2+ dye fluo-3AM and laser scanning confocal microscope(LSCM)after stimulation with100nmol·L-1 phorbol12-myristate13-acetate(PMA)and(or)5concentrations of hypericin(1，2，3，4and5μmol·L-1 ).RESULTS Normal fluorescence in RPE cells was strong and distributed throughout the cells.The nucleus appeared to be more fluorescent than the cytoplasm.After stimulation with PMA alone or5concentrations of hypericin，a rapid decrease in fluorescence intensity was observed.There was no obvious difference in decreased curve among5concentrations.However，after stimulation with a24h preincubation of PMA and5concentrations of hypericin，no further decrease was observed.CONCLUSION Fluo-3AM appears to be a good indicator of the change in Ca2+ occurring in RPE cells and hypericin is a strong inhibitor of Ca2+ influx channel.hypericin has potential as a therapeutic drug for pro-liferative vitreoretinopathy(PVR) ......