腹主动脉缩窄型高血压大鼠心肌肌浆网钙泵活力的测定

Determination of the activity of sarco-endoplasmic reticulum Ca^(2+)-ATP_(ase) in rats with myocardial hypertrophy induced by abdominal aortic constriction

目的:观察腹主动脉缩窄型高血压大鼠心肌肌浆网钙泵活力。方法:20只雄性SD大鼠随机分为2组(每组10只):假手术组和腹主动脉缩窄高血压组。鼠尾容积法测定术前1周和术后2周及4周的血压变化。4周后处死大鼠,测定大鼠心脏重量、左室重量和左室重量指数;无机磷酸根法测定心肌肌浆网钙泵活力,双波长荧光分光光度计检测心肌细胞内钙离子浓度。结果:腹主动脉缩窄型高血压组收缩压和左室重量指数明显高于假手术组(P<0.01);与假手术组比较,腹主动脉缩窄型高血压组心肌细胞内钙离子浓度明显升高(P<0.01),心肌肌浆网钙泵活力显著降低(P<0.01)。结论:心肌肌浆网钙泵活力下降、心肌细胞钙离子浓度升高可能参与了缩窄升主动脉引起压力超负荷所致大鼠的心肌肥厚。

Objective：To determine the activity of myocardial sarco-endoplasmic reticulum Ca^2 ＋ -ATPase （SERCA） in rats with cardiac hypertrophy induced by overloaded-pressure. Methods： Myocardial hypertrophy was indueed by abdominal aortic constriction （ AAC ） in 20 adult Sprague-Dawley rats,and the rats were randomized into groups of sham opera- tion and AAC（n = 10 each）. The measurement was preformed regarding systolic blood pressure, heart weight （HW） , body weight （BW） , left ventricular weight （LVW） and left ventricular weight index （LVW/BW, LVWI）. The activity of myocardial SERCA was determined by non-polar phosphate method. Ca^2 ＋ concentration in cardiomyocytes was detected by dual wave spectrofluorometer. Results： Compared with sham group, systolic blood pressure and LVWI in AAC group were significantly increased （P 〈 0. 01 ）. The activity of myocardial SERCA in AAC group was significantly lower than that in sham group （P 〈0.01 ） ,and Ca^2＋ concentra-tion of cardiomyocytes in AAC group was markedly higher than that in sham group （ P 〈 0. 01 ）. Conclusion ： The drop of myocardial SERCA activity might be involved in myocardial hypertrophy in rats with pressureoverload induced by abdominal aortic constriction.