钙调神经磷酸酶在冷应激高血压大鼠心肌肥厚中的作用

THE ROLE OF CALCINEURIN-DEPENDENT SIGNAL PATHWAY IN CARDIAC HYPERTROPHY OF COLD STRESS-INDUCED HYPERTENSIVE RATS

为探讨钙调神经磷酸酶信号通路在冷应激高血压大鼠心肌肥厚中的作用 ,将Wistar大鼠置于 (4± 2 )℃的冷环境中 ,每天 4h冷应激 8周 ,制备大鼠高血压和心肌肥厚模型 ,分析冷应激高血压大鼠血流动力学改变、心肌CaN活性和蛋白表达以及原癌基因c fos的表达。结果表明 ,冷应激大鼠血压、心率、心脏重量指数明显增加 ,左室室壁增厚和舒张功能下降 ,同时心肌CaN活性、CaN蛋白以及c fos表达明显增加。提示钙调神经磷酸酶依赖的信号通路可能参与了冷应激高血压大鼠心肌肥厚的病理过程。

To investigate the role of calcineurin dependent signal pathway in cardiac hypertrophy of cold stress induced hypertensive rats, 3 months old Wistar rats were exposed to cold (4±2℃) for 4 hours per day for 8 weeks to produce cold stress induced hypertension and cardiac hypertrophy. The systolic blood pressure(SBP), heart rate and hemodynamic parameters were measured using a force transducer.The heart/body weight ratio, CaN activity, CaN, c fos expression protein of cardiac tissure were also investigated. The results showed that SBP and heart rate in cold stress rats were significantly increased than that in nomal rats during the whole experiment( P <0 01). The ratio of heart/body weight and left ventricle diastolic pressure were increased markedly and the dp/dt max reduced significantly as compared with control rats. The activity of CaN was elevated distinctly and expression of CaN and c fos protein also increased notably in cold stress rats. These results suggest that cold stress might play an important role in the development of hypertension and cardiac hypertrophy, and calcineurin dependent signal pathway could be involved in cold stress induced cardiac hypertrophy.