再灌注早期应用雌二醇对缺血鼠心肌的保护作用

The protective effects of estradiol on ischemic rat myocardium during the early stage of reperfusion

目的 探讨再灌注早期应用 17β 雌二醇 (17β estradiol,E2 )对心肌缺血再灌注损伤 (MIRI)的影响。方法 采用Langendorff离体鼠心脏灌注模型 ,将 30只雌性卵巢切除 (OVX)大鼠随机均分为 3组。缺血再灌注组 (I R组 )用K H液预灌注 15min ,常温停灌 30min ,恢复K H液再灌注 30min。 0 1%二甲基亚砜组 (D组 )和 5 μmol LE2 组 (E组 )从再灌注第 6min起改用含相应药液的K H液灌注 2 5min ,余同I R组。记录各组心功能及冠脉流量 (CF) ,测量冠脉流出液中乳酸脱氢酶 (LDH)、肌酸磷酸激酶 (CPK)、心肌丙二醛 (MDA)含量及心肌超氧化物歧化酶 (SOD)活性的变化。结果 再灌 30min时 ,E组CF比I R、D组明显增加 (P <0 0 1) ;I R、D、E组心功能均降低 ,但I R和D组较E组更为显著 (P <0 0 1) ;E组SOD活性明显高于I R和D组 (P <0 0 1)而MDA、CPK和LDH的含量明显低于I R和D组 (P <0 0 1) ;I R组和D组之间未显示出统计学差异。结论 E2 可通过其抗氧化作用 ,防止MIRI。

Ovbective To study the protective effects of 17β-estradiol on isolated ischemic rat hearts in a modified Langendorff model. Methods Thirty rats performed bilateral ovariectomies were divided equally into three groups at random. A three-phase protocol was performed: (1) 15-minutes preperfusion,(2) 30-minutes global ischemia,(3) 30-minutes reperfusion. Treatment with 0.1% DMSO (group D) and 5 μmol/L 17β-estradiol+0.1% DMSO (group E) dissolved in K-H buffer was perfused from sixth minutes of reperfusion. Only K-H was perfused in the ischemia-reperfusion group (group I-R). The left ventricular pressure (LVP) and it's first derivative (±dp/dt max ) and coronary flow (CF) were recorded at the 15th minute of preperfusion and the 30th minute of reperfusion. Creatin phosphokinase (CPK) and lactic dehydrogenase (LDH) the coronary effluent,the content of malonaldehyde (MDA) and superoxide dismutase (SOD) activity of myocardium were measured at the 30th minute of reperfusion. Results After 30-minute reperfusion,restoration of heart function of group E treated with 17β-estradiol were better than that of group I-R and group D,with a higher coronary flow,and a lower CPK and LDH level (P<0.01). The SOD activity of myocardium was significantly higher and the concentration of myocardial MDA was significantly lower in group E than those in group D and group I-R (P<0.01). No statistically significant differences were observed between group I-R and group D. Conclusion 17β-estradiol might protect isolated rat hearts ischemia reperfusion injury in a modified Langendorff model through the possible mechanism of anti-oxidation of 17β-estradiol.