一氧化氮在培养的大鼠心肌细胞缺氧-复氧损伤中的作用

The effect of nitric oxide on hypoxia-reoxygenation injury of cardiomyocytes upon rats

目的：观察一氧化氮（ＮＯ）对心肌细胞缺氧－复氧损伤（ＨＲＩ）的作用。方法：培养的大鼠心肌细胞，培养液中分别预先加入ＮＯ前体Ｌ－精氨酸（Ｌ－Ａｒｇ）、ＮＯ供体ＳＩＮ－１或硝普钠（ＳＮＰ）、ＮＯＳ抑制剂Ｌ－ＮＮＡ或ＮＯＳ诱导剂脂多糖（ＬＰＳ），经缺氧１２０ｍｉｎ，复氧６０ｍｉｎ处理后，检测细胞存活率，乳酸脱氢酶（ＬＤＨ）漏出量，亚硝酸盐（ＮＯ２）含量及细胞诱导型ＮＯ合酶（ｉＮＯＳ）活性等指标的改变。结果：①与常氧组比较，缺氧－复氧ＨＲ降低细胞存活率（２３％，Ｐ＜０．０１），增加ＬＤＨ漏出（６２倍，Ｐ＜０．０１），ｉＮＯＳ活性（７７％，Ｐ＜０．０１），ＮＯ２含量（６１７％，Ｐ＜０．０１）。②ＨＲ前预先加入ＳＩＮ－１、ＳＮＰ或Ｌ－Ａｒｇ，均引起ＬＤＨ漏出进一步增高（Ｐ＜０．０１），细胞存活率进一步降低（Ｐ＜０．０１或Ｐ＜０．０５）。③Ｌ－ＮＮＡ２ｍｍｏｌ／Ｌ，单独应用对细胞损伤的影响无统计学意义，与Ｌ－Ａｒｇ联合应用，则减弱Ｌ－Ａｒｇ的细胞损伤作用。④ＬＰＳ１μｇ／ｍＬ，增加ｉＮＯＳ活性（２６倍，Ｐ＜０．０１）和ＬＤＨ漏出（５６％，Ｐ＜０．０１）。结论：ＮＯ加重心肌细胞ＨＲＩ。

Abstract AIM:To investigate the effect of nitric oxide (NO) on hypoxia and reoxygenation injury(HRI) of cardiomyocytes. METHODS:With cardiomyocytes cultured in newborn rats subjected to hypoxia 120 min and reoxygenation 60 min in the presence of either NO precursor L-arginine(L-Arg), or NO donors 3-morpholino sydnonimine-hydrochloride (SIN-1), or sodium nitroprusside (SNP), or NOS inhibitor N ω-nitro-L-arginine (L-NNA), or lipopolysaccharide (LPS), changes of cell viability, leakage of lactate dehydrogenase (LDH), inducible nitric oxide synthase (iNOS) activity and nitrite (NO 2) content were observed. RESULTS:①Hypoxia and reoxygenation reduced cell viability (23%, P <0.01),increased leakage of LDH (6.2 times, P <0.01), iNOS activity (77%, P <0.01) and NO 2 content (61.7%, P <0.01) vs 21% O 2 control group.②With SIN-1 or SNP or L-Arg pretreated, the leakage of LDH was further increased ( P <0.01) and cell viability was further reduced ( P <0.01 or P <0.05) compared with HR group. ③L-NNA (2mmol/L) had no significant effects on cell injury, but it attenuated the cell injury effects of L-arginine. ④ LPS increased iNOS activity (2.6 times, P <0.01) and the leakage of LDH (56%, P <0.01).CONCLUSION: NO can exacerbate cardiomyocytes HRI. It is a injury factor to cardiomycytes HRI. MeSH Nitric oxide; Cardiomyocyte; Reperfusion injury; Rat