低压稳恒直流电场在兔梗死心肌修复中的作用

Efficacy of the applied weak steady direct current electrical fields in a rabbit model of chronic myocardial infarction

目的探讨兔实验性心肌梗死(MI)时在心肌缺血和非缺血区域施加一定强度稳恒直流电场对梗死心肌的修复效应。方法家兔40只均予冠状动脉前降支结扎,分为心肌梗死(MI)组、平面电场2.0V组与平面电场3.0V组、透壁电场2.0V组与透壁电场3.0V组。分别给予相应的直流电场干预。4周后去甲肾上腺素激发实验分析心功能;Masson染色评估心肌梗死面积和心肌纤维化程度。结果平面电场2.0V、透壁电场2.0V和透壁电场3.0V治疗可改善MI后的收缩和舒张功能,也明显缩小了MI后瘢痕面积,同时降低梗死区边缘带纤维化程度,尤以透壁电场3.0V治疗时显著,而平面电场3.0V则无显著作用。结论适宜的低压稳恒直流电场可缩小兔实验性MI面积,降低心肌纤维化程度,改善左心室功能,对梗死心肌起到保护作用。

Objective To apply a weak steady DC EFs of 2.0 and 3.0 V/cm to a injuried and chronic infracted heart in rabbits in order to investigate whether important therapeutic effect on the repair of infarcted myocardium were induced.Methods Fourty Chinese rabbits in which myocardial infarction models without endotracheal intubation were established and were randomly divided into five groups including the myocardial infarction（MI）group,the plane electrical fields of 2.0 V（PEF 2.0 V）group,the plane electrical fields of 3.0 V（PEF 3.0 V）group,the transmural electrical fields of 2.0 V（TEF 2.0 V）group and the transmural electrical fields of 3.0 V（TEF 3.0 V）group.Either plane or transmural DC EFs of 2.0 V or 3.0 V were applied to ischemic myocardium of rabbit models of chronic myocardial infarction.After 4 weeks,cardiac function analysis by noradrenalin challenge and histopathological analyses were performed to evaluate the efficacy of the weak steady DC EFs applied on the surface of ischemic myocardium.Results Cardiac function analysis by noradrenalin demonstrated that cardiac systolic and diastolic function in PEF 2.0 V,TEF 2.0 V and TEF 3.0 V were more significantly improved than that in MI and PEF 3.0 V.Significant improvement was found in minimizing infarct area and lowering the extent of fibrosis among the 4 applied DC EFs groups,and the transmural electrical fields is superior to the plane electrical fields.Conclusions The eligible weak steady DC EFs applied on the surface of infarcted myocardium induces repairing effect of myocardial infarction,thereby protecting the myocardium.