颈动脉窦压力感受器电刺激对代谢综合征大鼠心脏脂代谢及功能的影响

The impact of carotid baroreceptor electric simulation on the cardiac lipid metabolism and cardiac function in metabolism syndrome rats

目的通过高脂饲料加果糖水喂养建立大鼠代谢综合征模型,观察颈动脉窦电刺激(carotid baroreceptor stimulation,CBS)对大鼠心脏脂代谢和功能的影响。方法将20只大鼠随机分成四组,即正常对照组(C-sham组)、代谢综合征对照组(MetS-sham组)、正常CBS组(C-CBS组)、代谢综合征CBS组(MetSCBS组)。所有大鼠用正常饲料加纯净水适应性喂养1周后开始实验,对照组采用正常饲料加纯净水喂养,代谢综合征组采用高脂饲料加果糖水喂养4周建立疾病模型,各组大鼠均喂养12周。所有大鼠于第5周行植入术,C-sham组与MetS-sham组植入模型,C-CBS与Mets-CBS组植入仪器,所有模型不发放电刺激,所有仪器发放电刺激。对所有大鼠每周行血压与体重测量,第12周所有大鼠行心脏超声检测,同时检测所有大鼠血清糖脂代谢指标以及肝功能。将大鼠处死后,取心脏、肝脏、脂肪称量。结果与C-sham组比MetSsham组心脏重量、左心室后壁收缩末期厚度、室间隔收缩末期厚度、射血分数呈上升趋势,左心室后壁舒张末期厚度、室间隔舒张末期厚度、左心室收缩末期内径、左心室舒张末期内径呈下降趋势,其中内脏脂肪含量[(35.97±4.38)g比(12.45±6.75)g,P<0.05]、射血分数差值[(0.98±0.01)比(0.93±0.03),P<0.05]有统计学意义,与MetS-sham组相比,MetS-CBS组左心室后壁收缩末期厚度、左心室后壁舒张末期厚度、室间隔收缩末期厚度、室间隔舒张末期厚度呈上升趋势,射血分数呈下降趋势,其中左心室后壁舒张末期厚度[(2.66±0.21)mm比(2.11±0.22)mm,P<0.05]差异有统计学意义。与C-sham组相比,MetS-sham组游离脂肪酸、总胆固醇比高密度脂蛋白胆固醇呈上升趋势,葡萄糖、高密度脂蛋白胆固醇呈下降趋势,其中两组游离脂肪酸[(1.21±0.32)mmol/L比(0.77±0.14)mmol/L,P<0.05]高密度脂蛋白胆固醇差值有统计学意义[(0.23±0.06)mmol/L比(0.31±0.05)mmol/L,P<0.05]。与MetS-sham组相比,MetS-CBS组高密度脂蛋白胆固醇呈上升趋势,游离脂肪酸、总胆固醇呈下降趋势。结论 CBS对大鼠心脏脂代谢和心功能有改善作用。

Objective To observe the effects of electric stimulation of carotid baroreceptor on the cardiac lipid metabolism and function in metabolism syndrome rats. Methods Randomly 20 rats were divided into 4 groups: C-sham group, MetS-sham group, C-CBS group and MetS-CBS group. The experiments started after all rats were adaptively fed with chew diet and pure drinking water for a week. The C-sham group and C-CBS group were given chew diet and pure drinking water while the MetS-sham group and MetS-CBS group were fed high fat diet and fructose drinking water;all of them were fed for 12 weeks for the whole experiment. The metabolic syndrome was established after 4 weeks of feeding. All the rats were implemented with the devices in the 5 th week. The rats in C-sham group and MetS-sham group were implemented with the sham device which gave no electrical stimulation and the C-CBS group and Met S-CBS group were implemented with carotid baroreceptor stimulator which gave electrical stimulation. All the rats were weekly measured for blood pressure and body weight. In the 12 th week, all the rats go an ultrasound examination of the heart. And the serum of all the rats was tested for the glucose and lipid metabolism indexes and liver function. After all rats were executed, the hearts and livers were taken out for measurement of weight. Results Compared with the C-sham group, the rats in Met Ssham group had lower heart weight. The left ventricular wall thickness at end-systole, interventricular septum thickness at end-systole and ejection fraction of the Met S-sham group appeared an uptrend, while left ventricular posterior wall thickness at end-diastole, interventricular septum thickness at end-diastole, left ventricular internal diameter at end-systole and left ventricular internal diameter at end-diastole appeared a downtrend. The visceral fat weight [(35.97±4.38)g vs.(12.45±6.75)g, P<0.05] and ejection fraction[(0.98±0.01) vs.(0.93±0.03), P<0.05] were statistically different between the 2 groups. Compared with Met S-sham group, Met S-CBS group appeared an uptrend in left ventricular posterior wall thickness at end-systole, left ventricular posterior wall thickness at enddiastole, interventricular septum thickness at end-systole and interventricular septum thickness at end-diastole, and appeared a downtrend in ejection fraction. Left ventricular posterior wall thickness at end-diastole [(2.66±0.21)mm vs.(2.11±0.22)mm, P<0.05] was statistically different between the two group. Compared with C-sham group, the Met S-sham group appeared an uptrend in free fatty acid, total cholesterol/high density lipoprotein cholesterol and a downtrend in glucose, high density lipoprotein cholesterol. Free fatty acid [(1.21 ± 0.32)mmol/L vs.(0.77 ± 0.14)mmol/L, P<0.05] and high density lipoprotein-cholesterol [(0.23±0.06)mmol/L vs.(0.31±0.05)mmol/L, P<0.05]between the two groups were statistically different between the two group. Compared with the Met S-sham group,the Mets-CBS group appeared an uptrend in high-density lipoprotein cholesterol and a downtrend in free fatty acid and total cholesterol. Conclusion CBS can improve the cardiac lipid metabolism and function of the rats.