地塞米松对培养的人视网膜色素上皮细胞生长的调控

目的检测地塞米松(dexamethasone,DEX)对培养的人视网膜色素上皮细胞(retinalpigmentepithelia,RPE)的调控。方法用四唑盐(MTT)实验，氚标胸腺嘧啶核苷(3H-thymidine,3H-TdR)掺入和流式细胞仪检测不同浓度DEX对RPE的作用。结果通过MTT及3H-TdR法，DEX浓度从32mg/L-320mg/L可增加培养的RPE的存活率和DNA合成，相反1000mg/L-3200mg/L为抑制作用，并呈剂量和时间依赖性。当DEX浓度为320mg/L时，S期和G2/M期细胞数增加28.3%，而1000mg/LDEX使其减少41.8%(P<0.05)。结论32mg/L-320mg/L的DEX促进培养的RPE的增殖，当DEX浓度>320mg/L时，则抑制增殖。DEX的抑制作用可能发生在S期和G2/M期。

Dexamethasone modulation on cultured human retinal pigment epithelial cell

Objective 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 cytometry. 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 3H TdR incorporation. The cell numbers in S phase and G 2/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 G 2/M phase.