猪缺血心肌侧支血管生成研究

目的：探讨猪冠状动脉高度狭窄后心肌侧支血管生成能力。方法：小型猪行胸廓切开术后，将纤维素样膨胀环套于冠状动脉左回旋支（LCX）上，随机分成三周组和八周组，分别于手术3周和8周后以单光子发射计算机断层扫描（SPECT）显像检测心肌灌注和心功能，冠状动脉造影检测LCX狭窄程度和侧支生成情况，组织学检测心肌梗死面积，免疫组织化学检测缺血心肌的血管密度。结果：SPECT显像示手术3周和8周后心肌缺血面积、静息最大缺血程度、左心室射血分数和LCX区局部室壁运动无显著性差异。冠状动脉造影示LCX狭窄程度均达95％以上，两组侧支血管生成均很不充分，仅3周组有1只见部分钝缘支分支显影。大体检查1只动物心内膜下心肌见小面积心肌梗死，心肌组织学检查示3只存在小面积坏死组织。血管密度检测示两组无显著性差异，和正常心肌血管密度比较也无明显差别。结论：小型猪慢性心肌缺血后侧支血管生成能力正常有限。

Coronary collateral development in ischemic myocardium of swine

Objective:To investigate the coronary collateral development in ischemic myocardium of miniature swine Methods:Miniature swine underwent thoracotomy and placement of an Ameroid constrictor on the left circumflex coronary artery(LCX) Myocardial perfusion and function were assessed by single photon emission computed tomography (SPECT) imaging, stenotic degree of LCX and collateral circulation by coronary angiography 3 or 8 weeks after placement of Ameroid constrictors Myocardial infarction area and vascular density were examined by histology or immunohistochemistry after sacrifice Results:SPECT imaging 8 weeks after placement of Ameroid constrictors demonstrated no significant difference in myocardial ischemia area, rest ischemic severity, ejection fraction of left ventricle and regional wall motion compared with those 3 weeks after Coronary angiography demonstrated that the stenotic degrees of LCX were all greater than 95% and only part obtuse marginal coronary branch in 1 animal was reconstituted Just small area of necrosis was revealed in 3 animals Immunohistochemistry assay revealed no significant difference in vascular density between three week group, eight week group and normal one Conclusion:The coronary collateral development in ischemic myocardium of miniature swine is very limited