硫化氢拮抗乳鼠心肌缺氧/复氧损伤机制初探

目的： 观察乳鼠心肌细胞内源性CSE/H2S通路的改变以及给予H2S供体对缺氧/复氧心肌细胞的影响,探讨该通路与心肌缺氧/复氧损伤的关系及作用机制。方法：出生48 h以内乳鼠心肌细胞原代培养,缺氧(2%O2、5%CO2)3 h/复氧(21%O2、5%CO2)2 h造成缺氧/复氧损伤,采用比色法检测培养液中乳酸脱氢酶(LDH)、心肌细胞丙二醛（MDA）及超氧化物歧化酶（SOD）; 采用RT-PCR 方法测定心肌细胞CSE mRNA表达。结果：与缺氧/复氧组相比,NaHS+IR组及IR+NaHS组心肌细胞存活率明显提高,培养液中LDH漏出量降低,心肌细胞中SOD产生增加,MDA生成减少,加入CSE的抑制剂PPG后各项观察指标无明显变化,同时RT-PCR结果显示IR损伤可以下调心肌细胞中CSE mRNA的表达。结论：缺氧前后加入NaHS可以明显减轻乳鼠心肌细胞缺氧/复氧损伤,此作用可能是通过降低自由基和保护细胞膜完整性完成的。

Effect of hydrogen sulfide on myocardial hypoxia/reoxygenation injury in vivo

AIM: To investigate the changes of endogenous cystathionine-γ-lyase/hydrogen sulfide pathway on hypoxia/reoxygenation injury in vivo and to explore the relationship between this pathway and hypoxia/reoxygenation injury. METHODS: Primary myocardial cell culture in vivo came from Wistar baby rats born less than 48 h. The cells were under the conditions of hypoxia (2% O2, 5% CO2) for 3 h and reoxygenation (21% O2, 5% CO2) for 2 h to induce hypoxia/reoxygenation injury. MTT was used to detect the cell survival in every group. The activities of lactate dehydrogenase (LDH) in culture medium, malondialdehyde (MDA) and superoxide dismutase (SOD) in myocardial cells were measured with colorimetry method. RT-PCR method was used to test CSE mRNA expression in myocardial cells. RESULTS: Compared to IR group, the cells in NaHS+IR and IR+NaHS groups had a higher survival rate, lower LDH concentration in culture medium, higher SOD activity and lower MDA in myocardial cells. At the same time, the results of RT-PCR displayed that CSE mRNA were down-regulated in myocardial cells after hypoxia/reoxygenation injury, and if CSE inhibitor PPG was added into the culture medium before hypoxia, no protective effects were detected. CONCLUSION: NaHS might protect the myocardial cells from hypoxia/reoxygenation injury through decreasing oxygen free radical production and stabilizing the cell membrane.