β-肾上腺素受体介导运动训练对老年大鼠心脏缺血预处理效应的影响

发布时间：2018-07-28 10:08

【摘要】：目的探讨运动训练能否恢复老年大鼠心脏缺血预处理(IP)效应及β-肾上腺素受体(β-AR)的可能作用机制。方法健康雄性SD成年或老年大鼠,实验分组:成年对照组、老年对照组和老年运动组,每组20只。老年运动组大鼠每天负重5%游泳,5次/w,持续90 d。离体心脏灌流行IP和(或)缺血再灌注(I/R),使用不同β-肾上腺素受体激动剂或阻滞剂,分离单个心肌细胞,测心肌细胞收缩幅度、存活率等。结果长期运动训练使老年鼠左心室重量增加显著,左心室/体重比显著增加(P0.05)。IP显著改善I/R损伤的成年大鼠和长期运动训练老年鼠的心功能,左心室收缩压(LVSP)、±dp/dtmax升高,左心室舒张末压(LVEDP)显著降低;提高了成年鼠和运动训练老年鼠的心肌细胞收缩幅度,但不能提高老年对照鼠心肌细胞收缩幅度;提高了成年鼠和运动训练老年鼠的心肌细胞存活率,但不能提高老年对照鼠心肌细胞存活率。IP时阻断β1-AR,IP不能恢复三组大鼠的心肌细胞收缩幅度;阻断β2-AR,IP能够恢复成年鼠,却不是老年对照鼠和运动训练老年鼠的心肌细胞收缩幅度。结论 IP可部分恢复运动训练老年大鼠的I/R损伤的心功能,其可能机制不仅涉及β1-AR的作用,β2-AR发挥着更为特别的作用。
[Abstract]:Objective to investigate whether exercise training can recover the (IP) effect of ischemic preconditioning and the possible mechanism of 尾-adrenergic receptor (尾-AR) in aged rats. Methods healthy male Sprague-Dawley (SD) rats were divided into three groups: adult control group, aged control group and aged exercise group with 20 rats in each group. The aged rats in the exercise group carried 5% weight per day for 5 times a day for 90 days. IP and / or ischemia-reperfusion (I / R) were used in isolated hearts to isolate individual cardiomyocytes with different 尾 -adrenergic agonists or blockers. The contraction amplitude and survival rate of cardiac myocytes were measured. Results Long-term exercise training significantly increased left ventricular weight, left ventricular / body weight ratio (P0.05). IP significantly improved cardiac function of adult rats with I / R injury and aged rats with long-term exercise training. Left ventricular systolic pressure (LVSP),) 卤dp/dtmax increased. Left ventricular end-diastolic pressure (LVEDP) decreased significantly, and increased the contraction amplitude of cardiac myocytes in adult rats and aged rats trained by exercise, but could not increase the contraction amplitude of cardiac myocytes in aged control rats. The cardiomyocyte survival rate of adult rats and aged rats trained by exercise was increased, but the myocardial cell contraction amplitude of three groups could not be recovered by blocking 尾 1-ARN IP when the survival rate of cardiac myocytes in aged control rats was increased, but 尾 2-ARN IP could be restored in adult rats. It was not the contractile amplitude of cardiac myocytes in aged control mice and exercise-trained aged rats. Conclusion IP can partially restore the cardiac function of I / R injury in aged rats after exercise training. The possible mechanism is not only the role of 尾 1-AR, but also that of 尾 2-AR.
【作者单位】：盐城卫生职业技术学院;
【基金】：盐城市医学科技发展计划项目(No.YK2011121)
【分类号】：R54

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