慢性缺氧-肺气肿大鼠膈肌生物力学特性变化

Experimental studies on changes of biomechanical properties in diaphragm of rats with chronic hypoxia and emphysema

目的复制大鼠缺氧-肺气肿模型,测定膈肌条生物力学特性,单个膈肌细胞的粘弹特性。方法制备慢性缺氧和肺气肿模型,检测膈肌条的收缩与疲劳特性,细胞微管吸吮系统测定单个膈肌细胞的粘弹特性。结果缺氧-肺气肿组颤搐收缩张力(Pt)和强直颤搐收缩张力(Po)显著下降,疲劳持续时间延长,力-频率曲线明显右移,缺氧-肺气肿组粘弹系数K1,K2,μ较对照组相应值明显降低,相差显著。结论缺氧-肺气肿大鼠膈肌疲劳与收缩特性减低,大鼠单个膈肌细胞的粘弹系数下降。

Objective To investigate the mechanical characteristics of diaphragmatic strip and the viscoelastic properties of single diaphragmatic cells in rat models of hypoxia- emphysema. Methods The rat models of hypoxia , emphysema and hypoxia - emphysema were developed. The contractility and fatigue properties of isolated diaphra^atic muscles, and the viscoelastic properties of rat diaphragmatic cells were assessed. Results The increases in twitch tension and tetanic tension, and the decrease in half- relaxation time in emphysema and emphysema- hypoxia rats were more significant than those in hypoxic rats and controls. The force - frequency curve was right shifted in emphysema and emphysema - hypoxia rats. The viscoelastic properties K1, K2 and μ of cells in emphysema and emphysema - hypoxia group were lower than those in hypoxia and control groups. Conclusion The contractility and fatigabihty of diaphragma are reduced in hypoxia- emphysema rats. Viscoelastic properties of single diaphragmatic cells are decreased change in emphysema rats.