Dexamethasone Modulation on Cultured Human Retinal Pigment Epithelial Cell

Purpose: Dexamethasone(DEX) was tested for its ability to modulate human retinal pigment epithelium (hRPE) cell proliferation in cell culture. Methods: DEX in different concentrations was added to cultured hRPE cells. The effects were measured with MTT method, 3H-thymidine(3H-TdR) incorporation and flow cytometw. Results: DEX increased survival rate and DNA synthesis from 32 mg/L to 320 mg/L under hRPE culture conditions, but paradoxically reduced them at 1 000 mg/L and 3 200 mg/L in dose and time dependent fashion by both MTT assay and 3 H-TdR incorporation. The cell numbers in S phase and G2/M phase increased 28.32 % at DEX concentration 320 mg/L, in contrast, reduced 41.84 % at 1 000 mg/L. Conclusion: DEX increased proliferation from 32 mg/L to 320 mg/L, and inhibited proliferation at concentrations greater than 320 mg/L. The inhibiting effect of DEX may happen in s phase and G2/M phase. Eye Sciernce 2001; 17:27 ～ 30.