中文摘要：

目的观察恒磁场对雷帕霉素作用下的大鼠内皮祖细胞（EPCs）增殖、凋亡及NO分泌的影响。方法采用密度梯度离心法获得雄性SD大鼠的骨髓EPCs，培养6天，随机分为5组：空白对照组、雷帕霉素（1μg／L）组及雷帕霉素＋不同强度的恒磁场组（0．1mT、0．5mT、1．0mT恒磁场组）。各组按分组条件作用24h后收集标本，MTT法检测EPCs增殖能力，流式细胞仪检测EPCs凋亡率，硝酸还原酶法检测NO含量。结果与空白对照组比较，雷帕霉素组抑制EPCs增殖能力0．252±0．006 vs 0．328±0．025，抑制NO分泌（22．8±4．3）μmol／L vs （36．9±5．6）μmol／L，促进EPCs凋亡（11．3±1．2）％vs（4．0±0．5）％，两组比较差异显著（P〈0．05）；0．5mT和1．0mT恒磁场组EPCs增殖能力分别为0．278±0．008，0．280±0．010、NO（28．0±4．2）μmol／L，（28．7±4．4）μmol／L，显著高于雷帕霉素组，EPCs凋亡率（7．5±0．6）％，（7．1±0．6）％），显著低于雷帕霉素组，差异显著（P〈0．05）。结论0．5mT和1．0mT恒磁场可拮抗雷帕霉素的作用，促进EPCs的增殖和NO分泌，并抑制EPCs凋亡。

英文摘要：

Objective To investigate effects of constant magnetic field （CMF） on proliferation,apoptosis and nitric oxide （NO） secretion of rat endothelial progenitor cells （EPCs） under rapamycin intervention. Methods EPCs were isolated from rat bone marrow by density gradient centrifugation and cultured on fibronectin-coated dishes. After six days of culture, the attached cells were divided into five groups, i. e., control group,rapamycin （1 μg/L） group, rapamycin with CMF 0.1 mT,0.5 mT or 1.0 mT groups. Samples were collected 24 hours after incubation. Cell proliferation was measured by MTT chromatometry. Apoptosis rate was determined by flow cytometry. NO content of the culture medium was measured by nitrate reductase method. Results Rapamycin 1 μg/L significantly inhibited proliferation and NO secretion and induced apoptosis of EPCs （P 〈0.05 vs control group）. Cell proliferation and NO secretion in rapamycin with CMF 0.5 mT and 1.0 mT groups were significantly higher than those in rapamycin group （P〈0.05）, whereas apoptosis rate was significantly lower than that in rapamycin group （P d0.05）. Conclusions CMF 0.5 mT and 1.0 mT can antagonize effects of rapamycin on EPCs,increase proliferation and NO secretion and decrease apoptosis rate of EPCs.