中文摘要：

目的 探讨钙池操纵性钙内流（SOCE）在慢性缺氧致大鼠肺动脉平滑肌细胞（PASMC）细胞内Ca2浓度（[Ca2＋]i）改变和细胞增殖中的作用及机制.方法 原代培养大鼠PASMC,分为常氧组（21％O2）和缺氧组（4％O2）,活细胞计数试剂盒-8（CCK-8）法检测PASMC增殖,细胞内钙浓度检测系统检测[Ca2＋]i和SOCE,并观察钙池操纵性钙通道（SOCC）拮抗剂SKF96365和氯化镍对缺氧组PASMC SOCE的影响.结果 缺氧24 h、36 h、48 h、60 h,PASMC增殖和升高[Ca2＋]i的效应呈时间依赖性,缺氧60h促进PASMC增殖（吸光度值1.12 ±0.09比0.71 ±0.05;P ＜0.05）和[Ca2＋]i升高[（214.8±20.4）nmol/L比（115.2±13.2） nmol/L;P＜ 0.05]的作用最明显.含硝苯地平（5 μmol/L）的无钙Krebs液孵育PASMC,环匹阿尼酸（CPA,10 μmol/L）导致PASMC[Ca2＋]i小幅升高,△[Ca2＋]i峰值为（113.3±49.3）nmol/L,慢性缺氧（4％O2,60 h）使PASMC[Ca2＋]i升高幅度增加,△[Ca2＋]i峰值达（193.2±22.7）nmol/L（P＜0.05）;恢复PASMC外Ca2＋后,CPA使PASMC[Ca2＋]i显著升高,△[Ca2＋]i峰值达（328.0±56.7）nmol/L,慢性缺氧导致CPA诱导的PASMC[Ca2＋]i升高更显著,A[Ca2＋]i峰值高达（526.0±33.7） nmol/L（P＜0.05）;SKF96365（50 μmol/L）和氯化镍（500 μmol/L）均能抑制慢性缺氧条件下CPA诱导的PASMC[Ca2＋]i升高,△[Ca2＋]i从（526.0±33.7）nmol/L分别降至（170.4±26.4） nmol/L和（177.4±45.9） nmol/L（P值均＜0.05）.结论 慢性缺氧促进大鼠PASMC肌浆网中Ca2＋释放,并增强SOCC活性,使经由SOCC内流的SOCE升高,从而导致PASMC的[Ca2＋]i升高,进而促进大鼠PASMC增殖.

英文摘要：

Objective To determine whether store-operated Ca2＋ entry （SOCE） is involved in chronic hypoxia-induced alteration of intracellular Ca2 ＋ concentration （[Ca2＋] i） and proliferation in pulmonary arterial smooth muscle cells （PASMC）.Methods Rat PASMCs were cultured and treated in normoxia （21%O2） or hypoxia （4% O2） condition.The proliferation of PASMC was detected by cell counting kit-8 （CCK-8） assay.[Ca2 ＋] i,SOCE and the effects of store-operated Ca2 ＋ channel （SOCC） inhibitors,SKF96365 and NiCl2,on SOCE in hypoxic PASMCs were tested by InCyte [Ca2 ＋] i measurement system.Results Hypoxia for 24-60 h augmented PASMC proliferation （1.12 ± 0.09 vs 0.71 ± 0.05,P 〈 0.05） and [Ca2 ＋] i [（214.8 ± 20.4） nmol/L vs （115.2 ± 13.2） nmol/L,P 〈 0.05] in a time-dependent manner with the maximum effect at 60 h.Perfusion of Ca2＋-free Krebs solution containing nifedipine （5 μ mol/L）,cyclopiazonic acid （CPA,10 μmol/L） in PASMCs caused a small transient increase of [Ca2＋]i with peak [Ca2＋]i （113.3 ± 49.3） nmol/L.Chronic hypoxia （4% O2,60 h） enhanced [Ca2＋]i level with peak value of （193.2 ± 22.7） nmol/L （P 〈 0.05） in PASMC.After restoration of extracellular Ca2＋,CPA caused marked increase of [Ca2＋]i with peak value of （328.0 ± 56.7） nmol/L.Chronic hypoxia strengthened CPA-induced increase of [Ca2 ＋] i with peak value of （526.0 ± 33.7） nmol/L （P 〈 0.05） in PASMCs.Either SKF96365 50 μmol/L or NiCl2 500 μmol/L distinctly attenuated CPA-induced enhancement of [Ca2 ＋] i,the peak value of which dropped from （526.0 ± 33.7） nmol/L to （170.4 ± 26.4） nmol/L （P〈0.05） or （177.4±45.9） nmol/L （P〈0.05） respectively.Conclusion Chronic hypoxia boosts the release of Ca2＋ from sarcoplasmic reticulum and promotes the activity of SOCC and SOCE,leading to [Ca2 ＋] i elevation and proliferation of rat PASMCs.