CT-1C-末端多肽对大鼠心肌缺血后再灌注心电图的影响

Influence of cardiotrophin-1 C-terminal peptides on ECG in rats following myocardial ischemia reperfusion injury

目的观察CT-1C-末端多肽不同干预方式对大鼠心肌缺血再灌注损伤心电图变化的影响。方法用结扎-松解SD大鼠冠状动脉左后降支的方法制作MI/R模型。27只SD大鼠随机分为4组:正常组(N,n=5);疾病组(D,n=6),结扎30min后开始再灌注;MI/R后干预组(T,n=8),结扎30min后开始再灌注并腹腔注射CT-1C-末端多肽100μg/kg;MI/R前干预组(O,n=8),腹腔注射CT-1C-末端多肽100μg/kg后进行MI/R实验。实验过程中,动态监测心电图,观察ST段、心率、PR间期及心律失常的发生情况。结果①结扎前4组大鼠的心率和PR间期与正常组大鼠无差别(F=0.6633,p>0.05);②结扎冠状动脉左后降支30min内,三组大鼠的心率都明显减慢,PR间期也明显延长,与结扎前比较差异有显著性(p<0.01)。再灌注2h内,疾病组(D)大鼠的心率进一步减慢,PR间期也进一步延长,与结扎后比较,差异不显著;MI/R前干预组大鼠的心率及PR间期与结扎后比较,差异有显著性(p<0.01)。MI/R后干预组(T)大鼠心率无明显变化,与结扎后比较,无显著差异;③缺血30min内,仅疾病组(D)有1只大鼠发生心律失常(16.67%);再灌注后,三组大鼠心律失常发生率均有增加,且各组间存在明显差别(x2=4.419,p<0.01),其中T组发生率最低(12.5%),O组发生率最高(62.5%),疾病组(50%)。结论①缺血及再灌注损伤均可导致SD大鼠心率减慢,PR间期延长,并易于再灌注后发生心律失常;②于缺血30min后开始再灌注的同时,施加CT-1C-末端多肽干预,可以防止SD大鼠MI/R后心率进一步减慢,减少心律失常的发生率;③SD大鼠接受CT-1C-末端多肽腹腔注射7天后,再遭受MI/R损伤,其再灌注后的心率进一步明显减慢,且心律失常的发生率增高。

Objective To study the change of ECG in rats following myocardial ischemia reperfusion injury which were treated with Carditrophin-1 C-terminal polypeptides pre- and post-ischemia. Methods The ischemia reperfusion heart model was established by ligating/loosening the left posterior decending branch of coronary artery in SD rats. Matched pairs of SD rats were treated with CT-1 C-terminal polypeptides either before or after myocardial isehemia, and the ECG were monitered. Results The heat rate （HR） were decended and the PR intermission were prolonged in the rats of all groups after the coronaries were ligated, and the two para were further decended and prolonged in the ischemia reperfusion group and pre-ischemia group and were maintained unchange in the post-ischemia group after the coronaries were loosened. The rate of arrhymia induced by ischemia reperfusion injury were decreased in the post-ischemia group but increased in pre-ischemia group. Conclusion Carditrophin-1 C-terminal polypeptides prevented the HR decending and PR intermission prolonging and decreased the rate of aiThymia induced by ischemia reperfusion injury when it was administered at the same time of reperfusing.It accelerated the effects of ischemia reperfusion injury on the HR and PR intermission and increased the rate of arrhymia when it was administered choronieally before ischemia.