可视化动缘探测系统同步检测慢性心衰对豚鼠心肌细胞舒、缩功能和钙瞬变的影响

目的建立豚鼠慢性充血性心力衰竭(CHF)模型,采用可视化动缘探测系统同步检测慢性心衰对豚鼠心肌细胞舒缩功能及钙瞬变的影响。方法采用有无呼吸困难、左心室质量与体质量比值、肺质量与体质量比值、室壁厚度及血流动力学指标判断,以降主动脉缩窄法建立豚鼠CHF模型成功后,以酶解法急性分离其左室心肌细胞,用可视化动缘探测系统同步检测慢性心衰豚鼠心肌细胞收缩力和钙瞬变的变化,并与正常豚鼠心肌细胞进行比较。结果降主动脉缩窄8 wk后,出现呼吸困难的豚鼠,其左室收缩压及舒张末压显著性增高,左室压上升和下降最大速率降低;左心室质量与体质量比值、肺质量与体质量比值及室壁厚度明显增高,呈现明显的心衰指征;心衰心肌细胞与正常细胞相比,其收缩幅度、收缩和舒张速度均明显减弱;舒张期细胞内钙升高,钙瞬变幅度减小,舒张期钙减少50%所需时间延长,但收缩期钙及细胞内钙达峰时间无明显改变。结论降主动脉缩窄8 wk后,豚鼠呼吸困难是判断CHF模型形成的指标;慢性心衰可使心肌细胞收缩力下降,钙瞬变幅度减小,这为探讨慢性心衰的发生机制提供了实验依据。

Effects of chronic heart failure on contractile/diastolic function and calcium transient in guinea pig ventricular myocytes detected simultaneously by video-based motion edge-detection system

Aim To develop the animal model of guinea pig chronic heart failure and detect effects of chronic heart failure on contractile/diastolic function and calcium transient in guinea pig ventricular myocytes by video-based motion edge-detection system simultaneously.Methods The chronic congestive heart failure(CHF) model was produced in guinea pig by a procedure that descenting aorta was constricted.The contrasting indexes in 8 weeks include: with or without dyspnea,hemodynamics,the mass ratio of left ventricle to body,the mass ratio of lung to body,and the width of left ventricle.Left ventricular myocytes were enzymatically isolated.Then the contractile and calcium transient of a single cell from both normal and failure hearts were assessed in guinea pigs by a video-based motion edge-detection system simultaneously.Results The models with dyspnea showed striking increasing in left ventricular systolic pressure and left ventricular end diastolic pressure,as well as the mass ratio of left ventricle to body,the mass ratio of lung to body and the width of left ventricular hypertrophy.The left ventricular pressure maximal rising and declining velocity significantly decreased.Compared with normal cells,the value of shorting,the contractile and diastolic velocity of myocytes decreased significantly.The diastolic calcium increased,the extent of calcium transient[FL(2K2] decreased and the time to 50% diastolic calcium lengthen.But systolic calcium,the time to peak calcium were unchanged.Conclusions The dyspnea is a important parameter for evaluating the animal CHF model of guinea pig formed by constricting the descending aortas of guinea pigs after 8 weeks.The chronic heart failure may decrease contractile and calcium transient extent in ventricular myocytes detected by video-based motion edge-detection system simultaneously,which might be helpful for the further studying the mechanism of the development of CHF.