右侧星状神经节阻滞对兔心力衰竭时β3肾上腺素能受体表达的影响

Effects of right stellate ganglion block on expression of β3-adrenoceptor in rabbits with heart failure

目的 评价右侧星状神经节阻滞对兔心力衰竭时β3肾上腺素能受体（β3-AR）表达的影响.方法 成年日本大耳白兔48只,雌雄不拘,体重2.5 ～ 3.0 kg,采用随机数字表法,将其分为假手术组（S组）、心力衰竭组（HF组）和右侧星状神经节阻滞组（RSGB组）,每组16只.采用开胸结扎左冠状动脉前降支的方法制备兔心力衰竭模型.S组仅在左心耳下穿线,不结扎.结扎后4周经超声多普勒检查,行右侧星状神经节置管术,RSGB组注入0.25％布比卡因2ml,1次/d,连续2周,S组和HF组注入生理盐水2 ml,方法同RSGB组.分别于结扎前1 d（T0）、结扎后4周星状神经节置管前（T1）、星状神经节第8次给药前（T2）、星状神经节末次给药后1 d（T3）时测定兔左室舒张末期内径（LVEDD）、左室收缩末期内径（LVESD）、左室射血分数（LVEF）及左室短轴缩短率（LVFS）.于T1.3时每组随机取8只兔处死,取左心室心尖组织,采用Western blot法检测β3-AR的表达.结果 与S组比较,HF组和RSGB组T1-3时LVEDD和LVESD增大,LVEF和LVFS降低,T1.3时β3-AR表达上调（P＜0.05）；与HF组比较,RSGB组T3时LVEDD和LVESD减小,LVEF和LVFS升高,心肌β3-AR表达下调（P＜0.05）.结论 右侧星状神经节阻滞可能通过下调心肌β3-AR表达改善心力衰竭兔的心功能.

Objective To evaluate the effects of the right stellate ganglion block on the expression of β3adrenoceptor （β3-AR） in rabbits with heart failure.Methods Forty-eight Japanese white rabbits of both sexes,weighing 2.5-3.0 kg,were randomly divided into 3 groups （n =16 each）：sham operation group （group S）,heart failure group （group HF） and right stellate ganglion block group （group RSGB）.Heart failure was induced by occlusion of left anterior descending branch of coronary artery and confirmed by ultrasonic cardiography 4 weeks later.A PE-10 catheter was inserted into the right stellate ganglion for administration of drugs.0.25％ bupivacaine 2 ml was injected through the catheter once a day for 2 weeks in group RSGB,while the equal volume of normal saline was injected instead of bupivacaine in S and HF groups.The left ventricular end-diastolic diameter （LVEDD）,left ventricular end-systolic diameter （LVESD）,ejection fraction （EF） and left ventricular fractional shortening （LVFS） were measured at 1 day before ligation （T0）,before catheter insertion （T1）,before 8th administration （T2）,and 1 day after the last administration （T3）.Eight rabbits were sacrificed at T1 and T3 in each group and myocardial specimens were obtained from the apex of the left ventricle for determination of the expression of β3-AR by Western blot.Results Compared with group S,the LVEDD and LVESD were significantly enlarged and LVEF and LVFS were decreased at T1-3,and the expression of β3-AR was up-regulated at T1,3 in groups HF and RSGB （P ＜ 0.05）.Compared with group HF,the LVEDD and LVESD were significantly decreased,LVEF and LVFS were increased,and the expression of β3-AR was significantly down-regulated at T3 in group RSGB （P ＜ 0.05）.Conclusion The right stellate ganglion block can improve the cardiac function of rabbits with heart failure through down-regulating the expression of β3-AR in myocardium.