冷应激对心肌细胞损伤的影响

EFFECT OF COLD STRESS ON INJURY OF RAT CARDIOMYOCYTE

目的 :探讨冷应激对心肌细胞损伤 ,特别是对心肌细胞凋亡的影响 ,为寻求保护或减轻冷应激心肌损伤研究提供可能途径。方法 :将体外培养的Wistar大鼠乳鼠心肌细胞分别置于 - 10℃、- 2 0℃进行冷应激 ,然后取培养液测定乳酸脱氢酶 (LDH)的活性 ,同时用流式细胞仪 (FCM )测定心肌细胞的凋亡率 ,用荧光分光光度法测定细胞内活性氧 (ROS)含量的变化。结果 :心肌细胞经 - 10℃、 - 2 0℃冷应激后 ,细胞凋亡率由 ( 3.73± 1.0 3) % ,分别增加到 ( 19.58±6.17) % (P <0 .0 1)和 ( 34 .54± 6.0 3) % (P <0 .0 1) ;ROS含量由 ( 18.8± 2 .1)荧光强度·mgpr- 1分别增加到 ( 34 .8± 2 .0 )和 ( 4 0 .8± 1.3)荧光强度·mgpr- 1(P <0 .0 1,P <0 .0 1) ;冷应激后 ,细胞培养液中LDH的活性也显著增高。结论 :冷应激后心肌细胞凋亡是心肌细胞死亡的重要途径 。

Objective:To observe the effects of cold stress on the injury of cardiomyocyte, especially the apoptosis of cardiomyocyte,so as to provide possible pathways for seeking protection of cold stress induced-myocardial injury.Methods:Cardiomyocytes were prepared from neonatal Wistar rats and stressed at -10 ℃and -20 ℃,then LDH activity in medium was assayed,the apoptosis rate in cardiomyocytes was measured with flow cytometry(FCM) method and the content of reactive oxygen species (ROS) with fluorescence spectrophotometer method.Results:The apoptosis rates of cardiomyocytes after cold stress at -10 ℃,-20 ℃ were increased from (3.73±1.03)% to (19.58±6.17)%(P<0.01)and (34.54±6.03)%(P<0.01)respectively;ROS contents were increased from(18.8±2.1) fluoscence intensity (FI)·mg pr -1 to (34.8±2.0)FI·mg pr -1 (P<0.01)and (40.8±1.3)FI·mg pr -1 (P<0.01)respectively;the activities of LDH in cultured medium were also increased.Conclusion:Apoptosis is an important pathway of the death of cardiomyocytes after cold stress.Oxidative stress caused by increasing of ROS in cardiomyocytes may be one of the significant mechanism of apoptosis.