白细胞介素-2参与缺氧/复氧引起的心肌功能损害

目的 :观察在缺氧 /复氧过程中白细胞介素 - 2 (IL- 2 )对心肌的影响及其可能机制。方法 :采用放射免疫法检测心肌组织中 IL- 2的含量 ;用视频跟踪系统和细胞内双波长钙荧光系统检测心肌细胞收缩和细胞内钙的变化。结果 :在缺血再灌注心肌组织中 IL- 2明显增多 [(14 .34± 5 .99vs2 2 .2 5± 3.6 8) ng/ g心肌组织 ]。在缺氧期间加 IL-2 (2 0 0 U/ ml) ,复氧期间心肌收缩和细胞内钙各参数回复的程度与单纯复氧的细胞相比均降低。IL- 2灌流后心肌线粒体丙二醛的含量在缺氧 /复氧后明显高于对照组 [(7.75± 0 .4 1vs6 .81± 0 .5 3) nmol/ mg蛋白 ]。结论 :IL- 2参与缺氧 /复氧引起的心肌功能损害 ,其机制可能与 IL- 2加重心肌线粒体脂质过氧化有关。

Role of interleukin-2 in the functional myocardial impairment induced by anoxia and reoxygenation

OBJECTIVE: To investigate the effect of interleukin-2 (IL-2) on myocardial impairment during ischemia/reperfusion or anoxia/reoxygenation. METHODS: Chemical anoxia was introduced in the isolated rat ventricular myocytes by Krebs-Henseleit (K-H) solution containing 10(-3) mol/L sodium dithionite. The video-tracking system and spectrofluorometric method were employed to verify the cell contraction and calcium homeostasis of the single myocyte. Radioimmunoassay was used to analyze the IL-2 levels in myocardium. RESULTS: The levels of IL-2 in myocardium subjected to ischemia/reperfusion were elevated [(14.34+/-5.99 compared with 22.25+/-3.68)ng/g, P<0.01]. During anoxia, cell contraction and the amplitude of electrically induced calcium transient were depressed and the parameters did not return to the pre-anoxia level during reoxygenation. IL-2 at 200 U/L administered during anoxia aggravated the effect of reoxygenation on cell contraction and calcium transient. After perfusion with IL-2, the malondialdehyde content of myocardial mitochondria was elevated. CONCLUSION: Coexistence of IL-2 during anoxia aggravates the effect of reoxygenation on the cell contraction and calcium homeostasis in the isolated rat ventricular myocytes, in which the mitochondrial lipid peroxidation induced by IL-2 is involved.