炙甘草汤对快速起搏心房肌结构重构的影响

Effect of Zhigancao Decoction on Atrial Structural Remodeling Induced by Rapid Atrial Pacing in Rabbits

目的观察炙甘草汤对快速心房起搏所致兔心房结构重构的影响,探讨其防治房颤的可能机制。方法将18只兔随机分为对照组(假手术组)、起搏组和药物组(起搏+炙甘草汤),每组各6只。家兔开胸后,用快速心房起搏法给予起搏组和药物组持续刺激(600次/min)8 h后观察3组兔左心房肌光镜和超微结构改变。结果光镜结构:与对照组比较,起搏组心房肌结构变化主要以急性损伤为主,如心肌纤维和间质水肿,伴心肌组织广泛充血和炎性细胞浸润;而药物组与起搏组比较无明显差异。超微结构:起搏组肌丝排列紊乱,部分溶解、断裂,线粒体肿胀明显、变形,空泡样改变,嵴排列紊乱、部分融合或消失。药物组比起搏组心房肌结构变化无减轻。结论快速心房起搏可致兔心房肌结构发生改变,炙甘草汤不能逆转其结构重构。

Objective： To investigate the effects of Zhigancao Decoction （ZD）on atrial structural remodeling in- duced by rapid atrial pacing in rabbits and to explore prevention and therapy mechanism of ZD on atrial fibrilla- tion（AF）. Methods： Eighteen rabbits were randomly divided into control group （n=6）,pacing group （n=6） and drug group （n=6）. After medial thoracotomy was performed,rabbits were paced at 600 beats per minute for 8 hours in both pacing group and drug group. After pacing 8 hours,the atrial tissue specimen was observed by light microscope and electron microscope in three groups. Results： Lens structures： compared with control group, pac- ing group varied mainly for acute injury, myocardial fibers and interstitial edema, and myocardial tissue hyperemia and inflammatory cells infiltration. The changes of drug group were not obvious compared with pacing group. U1- trastructures： Atrial muscle fiber disorder,partial dissolution,fracture,mitochondria swelling,deformation,vacuole change, crest disorder,partial fusion or disappear were seen in the pacing group. Conclusion： Atrial structural remodeling may be caused by rapid atrial pacing. ZD can not reverse atrial structural remodeling induced by rapid atrial pacing.