内源性NO对低氧下大鼠肺动脉平滑肌细胞增殖的影响

EFFECTS OF ENDOGENOUS NITRIC OXIDE ON PROLIFERATION OF PULMONARY ARTERY SMOOTH MUSCLE CELL IN HYPOXIA

目的探讨内源性一氧化氮(NO)对低氧下离体肺动脉平滑肌细胞(PASMCs)增殖的影响。方法原代培养Wistar大鼠PASMCs,分常氧组(21%O2,5%CO2)和低氧组(1%O2,94%N2,5%CO2)进行培养,分别应用非选择性一氧化氮合酶抑制剂NG-硝基-L-精氨酸甲酯(L-NG-nitro-arginine methyl ester,L-NAME)进行干预,用细胞计数和四甲基偶氮唑蓝比色法(MTT)检测细胞增殖水平。结果低氧下的肺动脉平滑肌细胞2天后明显增殖,与常氧组相比有显著性差异(P<0.01),5天后细胞数达到峰值。L-NAME低氧干预组细胞增殖水平明显高于低氧组和常氧组(P<0.01)。结论 L-NAME抑制内源性NO的产生进而促进低氧诱导的肺动脉平滑肌细胞增殖。

Objective To investigate the effect of endogenous nitric oxide（NO）on proliferation of rat pulmonary artery smooth muscle cells（PASMCs） in vitro in hypoxia.Methods The primary culture PASMCs of Wistar rat were randomly divided into normoxia group（21% O2,5% CO2）,hypoxia group（1% O2,94% N2,5% CO2）.Cultured PASMCs were intervened by L-NAME（L-NG-nitro-arginine methyl ester,a non selective nitric oxide synthase inhibitor）.The proliferation was tested by cell count and methyl thiazolyl tetrazolium（MTT）method.Results The PASMCs counts in hypoxia were more than normoxia group after 2 days,and the proliferation of PASMCs were more obvious in hypoxia group than normoxia group after 5 days（P〈0.01）.The proliferation of hypoxia ＋L-NAME group was significantly higher than that in normoxia group and hypoxia group（P〈0.01）.Conclusion L-NAME can inhibite the endogenous NO production and it further promote the proliferation of pulmonary smooth muscle cells induced by hypoxia.Inhibition of NO production will promote hypoxia-induced pulmonary artery smooth muscle cell proliferation.