高频超声心动图评价5/6肾切除大鼠心脏结构和功能的变化

Value of high-frequency echocardiography in evaluating the changes in cardiac structure and function in 5/6 nephrectomized rats

目的:通过5/6肾切除拟建立慢性肾心综合征大鼠动物模型,应用高频超声心动图动态检查其心脏的收缩与舒张功能,评价高频超声心动图在5/6肾切除造模大鼠慢性肾心综合征研究中的价值。方法:将健康SD大鼠24只随机分成假手术组和模型组两组;模型组采取5/6肾切除,假手术组模拟手术过程但不切除肾。于10周后,对2组大鼠行经胸超声心动图监测;然后经腹主动脉抽取动脉血以测定血肌酐和尿素氮;然后采用颈脱位法处死大鼠,取其心、肾进行形态学观察。结果:第10周末存活的模型组大鼠一般情况较假手术组差;高频超声可以清晰显示大鼠心脏结构,模型组大鼠心脏左室在舒张末期的内径(LVIDd),与假手术组比较有明显增加(P<0.05),模型组左室射血分数(EF)、短轴缩短率(FS)比假手术组均有降低(P<0.01),其余指标差异无统计学意义;模型组大鼠血清肌酐和尿素氮测值均较假手术组显著升高(P<0.01);模型组肾组织大部分肾小球萎缩、纤维化,肾小囊变狭窄其壁增厚,心肌细胞肥大变粗、排列分布不均匀、闰节不清晰等病理改变。结论:5/6肾切除可建立慢性肾心综合征大鼠动物模型;高频超声心动图可较好地评价造模大鼠的心脏结构及心功能的变化。

Objective:To establish a rat model of chronic cardiorenal syndrome by 5/6 nephrectomy,and toinvestigate the systolic and diastolic function of the heart by high-frequency echocardiography,as well as the valueof high-frequency echocardiography in the research on 5/6 nephrectomized rats with chronic cardiorenal syndrome.Methods:A total of 24 healthy Sprague-Dawley rats were randomly divided into sham-operation group and modelgroup. The rats in the model group were given 5/6 nephrectomy,and those in the sham-operation group were giventhe surgery without removing the kidney. Transthoracic echocardiography was performed at 10 weeks after surgery.Arterial blood samples were collected from the abdominal aorta to measure serum creatinine and urea nitrogen. Therats were sacrificed by cervical dislocation,and the morphological changes of the heart and the kidney wereobserved.Results:At the end of week 10,the model group had a worse general status than the sham-operationgroup. High-frequency echocardiography clearly showed cardiac structure; compared with the sham-operationgroup,the model group had a significant increase in left ventricular end-diastolic diameter(P < 0.05) andsignificant reductions in left ventricular ejection fraction and fractional shortening(P < 0.05),while there were nosignificant differences in the other indices between the two groups. The model group had significant increases inserum creatinine and urea nitrogen compared with the sham-operation group(P < 0.01). The model group showed pathological changes including atrophy and fibrosis of most glomeruli,narrowing of renal capsule and thickening ofits wall,hypertrophy and irregular arrangement of cardiomyocytes,and unclear intercalated disks.Conclusion:5/6 Nephrotomy can be used to establish a rat model of chronic cardiorenal syndrome, and high-frequencyechocardiography can well evaluate the changes in cardiac structure and function.