伴放线聚集杆菌感染加重小鼠心肌缺血再灌注损伤

Aggregatibacter actinomycetemcomitans infection aggravates myocardial ischemia/reperfusion injury

目的:探讨牙周主要致病菌伴放线聚集杆菌(Aggregatibacter actinomycetemcomitans,Aa)对实验性心肌缺血再灌注损伤的影响。方法:24只雄性C57BL/6小鼠皮下植入金属线圈形成腔室后,将Aa(n=12)或PBS(n=12)注射到腔室。每周1次,3周后制备心肌缺血再灌注模型,再灌注24小时后处死取血和心脏。心脏石蜡切片HE和Masson染色。处死前心脏超声心功能检测,左心室进行Evans blue-TTC染色。结果:感染组小鼠血清抗Aa特异性抗体滴度显著高于未感染组。与未感染Aa的I/R小鼠相比,Aa感染组的I/R小鼠左心室短轴缩短率(%EF)及射血分数(%ES)明显下降,两组间有统计学差异(P<0.01)。而且Aa感染组的I/R小鼠的心肌梗死面积/危险区面积明显增加。组织病理观察发现Aa感染组小鼠炎性细胞浸润增加,心肌间质纤维化加重。结论:伴放线聚集杆菌感染加重小鼠心肌缺血再灌注损伤,可能是心肌缺血再灌注损伤的一个潜在危险因素。

Objective:To investigate the effect of Aggregatibacter actinomycetemcomitans(Aa),a major periodontal pathogen infection on myocardial ischemia/reperfusion(I/R)injury.Methods:6-8 weeks wild type C57BL/6J mice which were injected with Aa(0.1ml,108 CFU/ml)in infection group and PBS in the control group.The I/R injury was induced by ligation of the left coronary artery for 30 min and reperfusion for 24 hours.Echocardipgraphy and Evans blue-TTC staining were performed.Results:Echocardiography indicated that left ventricular fraction shortening had decreased in the Aa infection I/R mice compared with the control group.The ratio of infarct area to area at risk is bigger in Aa infection group(53.41%±12.1%)than that in control group(39.15%±7.97%)(P<0.01).Aa infected I/R hearts showed more inflammatory infiltrates and fibrosis.Conclusion:These results suggested that Aa.may aggravate myocardial I/R injury.