摘要
目的探讨阈下电刺激对大鼠缺血心肌细胞凋亡及半胱氨酸天冬氨酸蛋白酶-3（caspase-3）表达的影响。方法将Wistar大鼠32只分为假手术组、心肌梗死组、电刺激缺血心肌组、电刺激非缺血心肌组，每组8只。用结扎大鼠左冠状动脉前降支的方法制备心肌梗死模型，在心外膜安置刺激电极，2个电刺激组均在心肌梗死第2天开始给予25Hz、0．3V电刺激，每天连续6h，刺激5d。运用原位缺口末端标记（TUNEL）法检测心肌细胞凋亡，免疫组化和逆转录-聚合酶链反应（RT—PCR）方法检测caspase-3的表达。结果①与假手术组比较，心肌梗死组及2个电刺激组心肌细胞凋亡指数均增加（P〈0．05）；与心肌梗死组比较，2个电刺激组心肌细胞凋亡指数减少（P〈0．05）；2个电刺激组间差异无统计学意义（P〉0．05）。②与假手术组比较，心肌梗死组及2个电刺激组心肌细胞easpase-3表达增高（P〈0．05）；与心肌梗死组比较，2个电刺激组心肌细胞凋亡指数降低（P〈0．05）；2个电刺激组间差异无统计学意义（P〉0．05）。结论25Hz阈下电刺激能降低大鼠缺血心肌细胞凋亡，其机制可能与下调caspase-3的表达有关；在心肌缺血区和非缺血区进行阈下电刺激均可减少大鼠缺血心肌细胞凋亡。
Objective To explore the effects of electrical stimulation below the contraction threshold on apoptosis and the expression of caspase-3 in cardiomyocytes after myocardial infarction in rats. Methods Thirty-two rats were randomly divided into 4 groups： a sham-operated group, a myocardial infarction group, an ischemic electrical stimulation group and a non-isehemic electrical stimulation group. TdT-mediated X-dUTP nick end labeling （TUNEL） was used to investigate apoptosis of eardiomyocytes. Reverse transcription-polymerase chain reaction （ RT- PCR） and immunohistochemical techniques were used to detect the expression of caspase-3, Results （1）Compared with the sham-operated group, the amount of apoptotic cardiomyocytes increased significantly in the two electrical stimulation groups and the ischemic myocardium group. Compared with the ischemic myncardium group, apoptotie cardiomyocytes decreased significantly in the two electrical stimulation groups. There was no significant difference between the two electrical stimulation groups. （2）Compared with the sham-operated group, in the ischemic myocardium group and the two electrical stimulation groups, expression of caspase-3 increased significantly, Compared with the ischemic myoeardium group, expression of caspase-3 decreased significantly in the two electrical stimulation groups. There was again no significant difference between the two electrical stimulation groups. Conclusions Electrical stimulation below the contraction threshold can reduce ischemic cardiomyocyte apoptosis in rats. The mechanisms may be associated with down-regulation of the expression of caspase-3. Electrical stimulation below the contraction threshold of the myocardium can also reduce cardiomyocyte apoptosis in rats.
出处
《中华物理医学与康复杂志》
CAS
CSCD
北大核心
2011年第11期808-811,共4页
Chinese Journal of Physical Medicine and Rehabilitation
基金
贵州省科学技术基金项目[黔科合丁字（2007）2089]
