妊娠兔心肌梗死后外周血干细胞变化及其与雌二醇的关系

目的研究妊娠兔结扎冠状动脉后外周血干细胞变化及其与雌激素的关系。方法实验分3组:妊娠心肌梗死组、非妊娠心肌梗死组及妊娠假手术组。妊娠组于怀孕第10天结扎冠状动脉左室支建立心肌梗死模型。通过流式细胞计数仪检测外周血CD90阳性细胞比例,同时测定血清雌二醇浓度。术后4周检测血流动力学指标。并使用ImageJ 1．31软件测量心肌梗死面积。结果妊娠心肌梗死组左室收缩末压、 dp／dtmax均高于非妊娠心肌梗死组。而左室舒张末压及 -dp／dtmax均低于非妊娠心肌梗死组。非妊娠心肌梗死组各时间点外周血CD90 细胞均低于妊娠组和妊娠假手术组 (P<0．01),且峰值在心梗后第5天,而妊娠心肌梗死组术后1 d外周血CD90 细胞升高最显著(P<0．05)。妊娠心肌梗死组和妊娠假手术组外周血CD90 细胞随孕期逐渐增加,至孕末达高峰,产后迅速下降。相应时间点血清雌二醇浓度妊娠兔显著升高。非妊娠心肌梗死组心梗后,血清雌二醇浓度元明显变化;妊娠组与妊娠假手术组血清雌二醇浓度随孕期逐渐增加,至孕末达高峰;血清雌二醇浓度与CD90 细胞比例呈显著正相关(r=0．725;P<0．01)。与非妊娠心肌梗死组相比,妊娠心肌梗死组梗死面积较小(22．17±6．34％ vs 38．86±5．97％;P<0．05)。结论妊娠兔外周血干细胞明显升高;并随孕期增加,至孕末达高峰。产后10 d恢复正常,其外周血干细胞数量与血清雌二醇浓度成正相关。妊娠兔心肌梗死后,干细胞动员提前发生心肌梗死面积小,且心脏收缩及舒张功能优于非妊娠者。

Correlation of changes in circulating bone marrow stem cells in pregnant rabbits after acute myocardial infarction with serum estradiol

OBJECTIVE: To investigate the changes in circulating bone marrow stem cells in pregnant rabbits after AMI (AMI) and their relationship with estradiol. METHODS: Three groups of rabbits were used, namely pregnancy and AMI group, AMI group without pregnancy, and sham operation group with pregnancy. The ratio of CD90(+) cells in the peripheral blood was determined with flow cytometry in all the rabbits, and serum estradiol level measured. Four weeks after AMI, hemodynamic measurements were carried out. The morphological changes of the myocardial tissues were examined with ImageJ 1.31. RESULTS AND CONCLUSION: Four weeks after AMI, the two pregnancy groups showed a higher Left ventricular end systolic pressure(LVESP) and+dp/dtmax, lower left ventricular end-diastolic pressure (LVEDP) and -dp/dtmax and high levels of CD90(+) cells in peripheral blood than AMI group without pregnancy (P<0.01). The ratio of circulating CD90(+) cells increased gradually with gestational age and peaked at the end stage of pregnancy. After delivery the circulating CD90+ cell ratio decreased sharply, showing a significant correlation with serum estradiol level (r=0.725, P<0.01). Four weeks after AMI, the pregnancy group had smaller myocardial infarction (MI) volume than the non-pregnant group (22.17+/-6.34% vs 38.86+/-5.97%, P<0.05). Circulating bone marrow stem cells increased during pregnancy with gestational age and peaked at the end stage of pregnancy. Ten days after delivery, the stem cells resumed basically the normal level. The proportion of circulating bone marrow stem cells was significantly correlated with the level of serum estradiol during pregnancy, and mobilization of the bone marrow stem cells induced by acute ischemic event in pregnant rabbits was advanced. 4 weeks after AMI, the pregnant rabbits showed better heart contraction and diastolic function than the non-pregnant ones.