一氧化氮对缺氧/复氧乳鼠心肌细胞内游离钙的影响

目的研究一氧化氮供体S-亚硝基-已酰青酶胺(SNAP)对缺氧/复氧乳鼠心肌细胞内游离钙浓度的影响。方法培养20×5只SD大鼠(1~3)d的心肌细胞,随机分为5组:A组为正常对照组;B组为单纯缺氧/复氧组(A/R缺氧2 h复氧1 h);C组为NO预处理组加入SNAP使其终浓度分别为0.1 mmol/L,预处理20 min后行A/R;D组为NO预处理组加入SNAP使其终浓度为1 mmol/L,预处理20 min后行A/R;E组为NO预处理组加入SNAP使其终浓度为2 mmol/L,预处理20 min后行A/R。与复氧后应用特异性Ca2+荧光指示剂Fluo-3/AM负载细胞,激光共聚焦显微镜检测游离Ca2+浓度。结果与正常组相比,单纯缺氧/复氧组钙浓度明显升高(P<0.01);0.1 mmol/L和1 mmol/L SNAP能明显降低钙超载(与B组相比,P<0.01),2 mmol/L SNAP组加重钙超载(与B组相比,P>0.05)。结论一氧化氮通过降低细胞内钙超载而减轻缺氧/复氧对心肌细胞的损伤,其作用有浓度依赖性。

Effects of Nitric oxide (NO) on intracellular calcium in anoxia/reoxygenation injury of neonatal rat cardiomyocytes

Objective To study the effects of nitric oxide donor(SNAP) on intracellular calcium in anoxia/reoxygenation injury of neonatal rat cardiomyocytes. Methods The cultured myocardial cells of neonatal SD rats were randomly divided into five groups,control group(A): without any treatment;anoxia/reoxygenation group(B): 2h anoxia followed by 1h reoxygenation;NO preconditioning groups(C): adding SNAP into culture medium to form different final concentrations,for 20 minutes preconditioning and then A/R.After reoxygenation,intracellular free Ca~(2+) concentration was measured by calcium fluorescent probe Fluo3/AM and laser confocal microscope.Results Compared with control group,anoxia/reoxygenation group caused great overload of intracellular Calcium(P<0.01).0.1 mmol/L SNAP and 1mmol/L SNAP significantly attenuated the change(P<0.01 vs B),and 2 mmol/L SNAP group aggravated the level of high intracellular Calcium.Conclusions NO alleviated the anoxia/reoxygenation injury on neonatal rat cardiomyocytes by attenuating the overloading of intracellular calcium,and the effects were concentration-dependent.