心肌细胞凋亡对老年大鼠心脏功能的影响

Effect of cardiomyocyte apoptosis on heart function of aged rats

目的观察心肌细胞凋亡在老年大鼠心功能降低中的作用。方法将大鼠分为成年组(n=10)、老年组(n=10)以及广谱的caspase抑制剂Z-VAD-FMK组(n=10)。MS2000生物信号记录分析系统记录各组大鼠的心脏功能,用TUNEL和caspase-3活性检测各组大鼠的凋亡情况;并分析老年大鼠凋亡与心功能的关系。结果与成年大鼠相比,老年大鼠的心重/体重比显著下降,心肌收缩及舒张功能均明显降低,老年大鼠心肌细胞的凋亡明显增加。并且,caspase-3的水平与心肌收缩指数呈负相关(r=-0.772,P<0.01),与左室舒张压呈正相关(r=0.718,P<0.01)。阻断老年大鼠心肌的凋亡后,心肌的收缩和舒张功能明显改善。结论心肌细胞凋亡在老年大鼠心功能下降中发挥着重要作用,提示临床可以通过抗凋亡措施来减少心肌细胞丢失进而延缓心功能的下降。

Objective To explore the effect of cardiomyocyte apoptosis on heart function in aged rats.Methods The rats were divided into three groups：adult group（n =10）,aged group （n =10） and Z-VAD-FMK group（n =10）.MS2000 biological signal recording and analyzing system was used to record the heart function.TUNEL and caspase-3 activity were used to observe the cardiomyocyte apoptosis in rats.Then,the relationship between apoptosis and the change of heart function were analyzed.Results Compared with adult rats,the heart weight/body weight ratio significantly decreased in aged rats.The myocardial systolic and diastolic functions were significantly lower in aged rats than those in adult rats.Compared with adult rats,the myocardial cells apoptosis was significantly increased in aged rats.At the same time,caspase-3 level was negatively correlated with the contractility index（r =-0.772,P ＜ 0.01） and positively correlated with the left ventricular diastolic pressure （LVDP） （r =0.718,P ＜ 0.01）.Furthermore,myocardial systolic and diastolic functions were improved significantly after Z-VAD-FMK blocking the cardiomyocyte apoptosis in aged rats.Conclusion These data implicate that the myocardial apoptosis plays an important role in decreasing heart function in aged rats and the anti-apoptosis therapy might be effective for improving heart function in aged rats.