中介素(IMD)对大鼠心肌细胞缺氧-复氧损伤的作用

The effects of intermedin(IMD) on hxypoxia/reoxygenation injury in rats cardiac myocytes

目的探讨中介素(IMD)对大鼠体外培养心肌细胞缺氧-复氧损伤的作用。方法用大鼠H9c2心肌细胞株制作实验模型,样本分为对照组、缺氧-复氧组(缺氧1h、复氧30min)、IMD组(缺氧-复氧前30min加入10-7mol/L IMD)。采用MTT比色法检测心肌细胞活力;透射电镜观察细胞超微结构;激光共聚焦显微镜观察并测定细胞内钙离子浓度;流式细胞术测定细胞凋亡率。结果与对照组比较,缺氧-复氧组和IMD组细胞存活率显著降低,而IMD处理组明显升高细胞存活率(P<0.01);在形态学上,IMD预处理可明显减轻缺氧-复氧对大鼠心肌细胞的损伤;缺氧-复氧组细胞[Ca2+]i荧光强度和细胞凋亡率比对照组显著升高,IMD预处理可明显降低上述升高的比率(P<0.01)。结论 IMD对大鼠心肌细胞缺氧-复氧损伤有一定保护作用,提高心肌细胞存活率、减轻心肌细胞钙超载和抑制凋亡是其作用途径。

Objective To investigate the effects of intermedin on the H9c2 rat cardiac myocytes after hypoxia/reoxygenation injury. Methods H9c2 Cell line from rat cardiac myocytes were divided into control group, H/R group and IMD group （H/R ＋ 10-7mol/L IMD）. MTY assay was performed to assess the cell viability and the changes in cell morphology were observed by transmission electron microscopy （TEM）. The intracellular calcium concentration [ Ca2＋ ] i of cultured cardiomyocytes was determined by fluo-3-based laser confocal scanning microscopy. The flow cytometry based on Annexin V FITC/PI double staining was used to measure cardiomyocyte apoptosis. Results The cell viability of the cardiac myocytes cultured were reduced under Hypoxia/reoxygenation （P 〈 0. 01 ） , but the cell viability was significantly increased in IMD group compared with that in H/R groups （ P 〈 0. 01 ）. The apoptotie changes of H9e2 was obviously in H/R group than which in the IMD group by the Electron microscopy. The calcium contents and apoptotic rate were significantly higher in H/R groups than in control group （ P 〈 0. 01 ） ; but IMD could reduce the calcium contents and apoptotic rate after H/R （P 〈 0. 01 ）. Conclusion Our results suggest that the protective effect of IMD against H/R injury in H9c2 rat cardiac myocytes, and IMD maybe play the roles according to prevent the calcium overload and inhibit the apoptosis in ischemic myocyte.