AIM:To study caspase-3 gene expression and [Ca2+]i homeostasis in verapamil(Ver)-induced human retinal pigment epithelium(RPE)cells apoptosis.METHODS:Ver 80mg/L was applied in cultured human RPE cells for 12,24 and 48 hours to induce RPE cells apoptosis.The expression of apoptotic effector gene caspase-3 was assessed by reverse transcription polymerase chain reaction(RT-PCR).Single cell was measured using fluorescence indicator Fura-3/AM with MetaFluo4.5/coolsnapfx/IX70 intracellular Ca2+ fluorescence imaging system.RESULTS:High levels of expression of caspase-3 mRNA were observed in normal RPE cells and it significantly increased after co-cultured with Ver.The fluorescence in resting RPE cells was strong and distributed throughout the cells.The nucleus appeared more fluorescent than the cytoplasm.Calcium fluorescence of RPE cells attenuated after co-cultured with Ver.CONCLUSION:Up-regulation of caspase-3 gene expression and disturbance of [Ca2+]i homeostasis might play pivotal roles in Ver-induced RPE cells apoptosis.