贝那普利对快速心房起搏家兔心房电重构的影响

目的 观察贝那普利对8h心房快速起搏家兔心房电重构(AER)的影响。方法取12只家兔,随机分为二组,对照组(生理盐水15ml/d),贝那普利组[5mg/(kg·d)溶于15ml生理盐水中],灌胃2周。①分别于起搏前、中、后测刺激频率为200ms、150ms时心房有效不应期(AERP200、AERP150)。②取未起搏家兔及每组起搏8h后家兔右心耳组织观察超微结构。结果①8h心房快速起搏使对照组家兔AERP缩短,AERP频率自适应性出现了下降—消失—逆转,心房肌超微结构可见线粒体肿胀、嵴溶解,糖原聚集;停止起搏后30min AERP及AERP频率自适应性基本恢复。②贝那普利组家兔心房快速起搏8h过程中各观测点AERP较起搏前无明显变化,家兔心房肌细胞超微结构基本正常。结论①心房快速起搏8h可致AER和心房肌细胞发生超微结构改变。②贝那普利可以阻止心房快速起搏8h所致AER及心房肌超微结构改变。

EFFECTS OF BENAZEPRIL ON ATRIAL ELECTRICAL REMODELING IN RAPID ATRIAL PACING RABBITS

Objective To observe the effects of Benazepril on atrial electrical remodeling in rapid atrial pacing rabbits. Methods We randomly assigned 12 rabbits into two groups: Control group (normal saline 15ml/d);Benazepril group(5mg/(kg.d) in saline 15ml/d). After 2 weeks' pretreatment, each rabbit was paced with maximal atrial capture rate for 8 hours. (1)Atrial Effective Refractoriness Period (AERP200,AERP150)was observed before and after the rapid pacing.(2)The atrial myocardium tissues were collected from normal rabbit and 8 hours paced rabbits offset the pacing. Results (1)In saline group,AERP significantly shortened during 8 hours' rapid pacing, the rate adaptation of AERP was lost; the ultrastructral changes (swelling of mitochordrial and the accumulation of glycogen)were observed. (2)In Benazepril group, the shortening of AERP after 8 hours' rapid pacing and the ultrastructral changes were completely inhibited. Conclusion (1)After 8 hours' rapid atrial pacing, Atrial Electrical Remodeling (AER) and ultrastructral changes were observed in rabbits of saline group. (2)The rapid atrial pacing induced AER and the ultrastructral changes were inhibited by pretreatment of Benazepril.