高血压大鼠心肌2型小电导-Ca2+-激活-K+通道蛋白（SK2）表达的变化

The changes of the expression of 2-type small conductance-Ca2+-activating-K+（SK2） channel protein in hypertensive rat myocardium

目的:观察高血压大鼠心肌细胞2型小电导-Ca^2+-激活-K^+(SK2)通道蛋白表达情况。方法:12只健康成年雄性SD大鼠随机分为对照组(5只)和实验组(7只),实验组采用N’-硝基-L-精氨酸(L-NNA 15 mg/(kg·d))腹腔注射制备高血压模型,对照组以等体积生理盐水腹腔注射,每天称量大鼠体重,每周测量血压及心电图变化,4周后处死大鼠取心脏;采用Western blot的方法检测心肌SK2通道蛋白表达水平。结果:给药4周后,与对照组相比,实验组大鼠血压明显升高(P<0.05),心电图QRS时长和R-R间期延长,实验组大鼠心房组织和心室组织SK2通道的表达均明显升高(1.12±0.18 vs 0.52±0.99,1.64±0.26 vs 0.99±0.22,P<0.05)。结论:高血压模型大鼠心房和心室SK2通道表达增加,其可能是导致高血压模型大鼠出现心律失常的机制之一,为高血压疾病的治疗和预后提供新的思路和策略。

Objective: To investigate the expression of 2-type small conductance-Ca^2+-activating-K^+( SK2) channel protein in hypertensive rat myocardial cells. Methods: Twelve healthy adult male SD rats were randomly divided into control group( n = 5) and experimental group( n = 7). The rats of experimental group were injected intraperitoneally with N’-nitro-L-arginine( L-NNA 15 mg/( kg·d)) while the rats of control group were injected intraperitoneally with isometrical normal saline( 15 ml/( kg·d)). The body weight,blood pressure and electrocardiogram of the rats were measured every week. After 4 weeks,the rats were sacrificed to obtain hearts,and the expression of SK2 channel protein in myocardium was detected by Western blot. Results: After 4 weeks of administration,compared with the control group,the blood pressure in the experimental group was significantly elevated( P<0. 05),QRS duration and R-R interval were prolonged,and the expressions of SK2 channel in the atrial and ventricular tissue of the experimental group were significantly higher than those in the control group( 1. 12±0. 18,1. 64±0. 26,P < 0. 05). Conclusion: The expressions of atrial and ventricular SK2 pathway are increased in hypertensive model rats. It may be one of the mechanism leading to arrhythmias in hypertensive model rats and can provide new ideas and strategies for the treatment and prognosis of hypertensive diseases.