早期慢性肾脏疾病心脏病变的实验研究

Cardiac impairment in early chronic kidney disease:an experimental study in rats

目的研究早期慢性肾脏疾病大鼠心脏病变情况。方法通过减少肾脏切除量和缩短喂养时间方法建立早期慢性肾脏疾病大鼠动物模型,分析其心脏病变,包括心脏重/体重比值、心肌细胞增大、心肌间质纤维化程度和心肌间质Ⅰ型、Ⅲ型胶原含量等。结果(1)实验组大鼠血尿素氮水平、尿白蛋白/肌酐比值、肾小球系膜增生程度均高于对照组,但实验组和对照组之间血肌酐水平差异无统计学意义,且病理改变较轻,表明早期CKD模型制作是成功的。(2)实验组大鼠心脏重/体重比值高于对照组(P<0.01),心肌细胞肥大,心肌间质纤维化明显。免疫组化测定显示心肌组织内Ⅰ型和Ⅲ型胶原量均高于对照组(P均<0.01)。结论心脏病变在早期CKD大鼠动物模型中即已经存在,表现为重量增加、间质纤维化、胶原增多等。

Objective To examine cardiac impairment in early chronic kidney disease （CKD） in a rat model. Methods The early CKD animal model was established by subtotal nephrectomy （70%±2.0%） and shortening the feeding time of the rais （10 weeks）. Heart impairment was examined with respect to the heart/body weight ratio, hypertrophy of cardiomyocytes and interstitial fibrosis. Collagen I and Ⅲ in myocardial tissue were measured by immunohistochemistry, Results （1） The mean percentage of removed kidney was 70.14±2.00%. In the experimental group, the main pathological change of the kidney was glomerular mesangial prnliferation. Focal segmental glomerular sclerosis was rare. Blood urea nitrogen （BUN）, the urinary albumin/creatinine ratio and the degree of glomerular mesangial proliferation were higher in the experimental group than those in the control group （P〈0.01）, but there was no significant difference in serum creatinine between the two groups; （2） Compared with the control group, the heart/body weight ratio was higher （P〈0.01） and pathological changes including hypertrophy of cardiomyocytes and interstitial fibrosis were more severe in the experimental group. Immunohistochemistry results showed that collagen I and collagen Ⅲ in the myocardial tissue increased significantly in the experimental group. Conclusions Cardiac impairment was found in the early CKD animal model, mainly including increased heart weight, hypertrophy of cardiomyocytes, interstitial fibrosis, and increased levels of collagen I and collagen Ⅲ.