缺氧复氧诱导的心肌细胞凋亡及一氧化氮对此过程的作用

目的　研究缺氧复氧损伤诱导体外培养的新生大鼠心肌细胞凋亡及一氧化氮 (NO)对此过程的作用。方法　取体外培养的新生大鼠心肌细胞 ,分两组 ,一组于 0 95N2 、0 0 5CO2 孵箱中培养 16h、32h、4 8h ,再恢复正常条件培养6h ,造成缺氧复氧损伤的细胞模型 ,TUNEL法观察心肌细胞凋亡形态学特征 ,流式细胞仪检测心肌细胞凋亡率 ;另一组缺氧培养 16h、32h、4 8h后 ,将NO供体亚硝基青霉胺(SNAP)加入培养基中 ,使其终浓度为 10 0 μmol·L-1,再于正常条件培养 6h ,检测心肌细胞凋亡率。结果　心肌细胞在缺氧 16h、32h和 4 8h后复氧 6h ,TUNEL法可检测到阳性的凋亡细胞 ,流式细胞仪检测其凋亡率分别为 :5 5 %±0 7% ,11 0± 1 1%和 14 2 %± 1 6 % ;心肌细胞缺氧培养16h、32h、4 8h后加入SNAP ,再复氧 6h ,流式细胞仪检测其凋亡率分别为 :3 2 %± 0 7% ,7 8%± 0 7%和 10 9%±1 0 %。结论　缺氧复氧损伤引起的心肌细胞凋亡率随着缺氧时间的延长而增高 ;NO对缺氧复氧损伤引起的心肌细胞凋亡有抑制作用

Hypoxia-reoxygenation induced apoptosis of cardiomyocytes and the effect of nitric oxide

AIM To study hypoxia reoxygenation induced apoptosis of neonatal rat cardiomyocytes and the roles of nitric oxide in this process. METHODS Cultured neonatal rat cardiomyocytes were divided into two groups. Cells of one group were cultured in an incubator of 950 mL·L -1 N 2 and 50 mL·L -1 CO 2 for 16 h, 32 h and 48 h followed by normal incubation for 6h to form the cell model of hypoxia reoxygenation injury.Cells of another group were cultured in the same hypoxia condition for 16 h, 32 h and 48 h. Before they were put in normal condition for 6 h, NO donor SNAP was added to the media to form the final concentration of 100 μmol·L -1 . Apoptosis was detected by TUNEL and flow cytometer. RESULTS Apoptotic cells were detected by TUNEL after hypoxia of 16 h, 32 h and 48 h followed by 6 h reoxygenation and the apoptotic rates of cardiomyocytes were (5 5±0 7)%, (11 0±1 1)% and (14 2±1 6)% respectively detectedby flow cytometer. The apoptotic rates of myocardiums with SNAP were (3 2±0 7)%, (7 8±0 7)% and (10 9±1 0)% respsctively. CONCLUSION The apoptotic rates of cardiomyocytes undergoing hypoxia reoxygenation injury increase with time of hypoxia; NO can inhibit apoptotic rates of cardiomyocytes in this pathological process and thus may have a protective effect on cardiomyocytes.