经膀胱颈部分结扎建立膀胱输尿管返流性肾损害动物模型

Establishment of an Animal Model of Vesicoureteral Reflux Renal Injury through Partial Bladder Outlet Obstruction

目的建立一种膀胱出口梗阻导致的返流性肾损害动物模型。方法取6~8周龄雄性C57BL/6小鼠60只,随机划分为对照组、假手术组和膀胱颈部分结扎(PBOO)组,每组20只,PBOO组小鼠麻醉后开腹分离膀胱颈,用0.3 mm直径的金属棒引导部分结扎膀胱颈,假手术组仅开腹分离膀胱颈,不结扎,对照组不做处理。术后7 d,每组随机挑选12只存活的小鼠,观察膀胱、输尿管、肾盂和肾脏大体变化,行经膀胱逆行性尿路造影,取肾组织进行组织病理学分析,Western blot、免疫荧光和免疫组化分别检测波形蛋白、增殖细胞核抗原(PCNA)、α平滑肌肌动蛋白(α-SMA)表达水平。结果与对照组和假手术组相比,PBOO组小鼠膀胱、输尿管、肾盂明显扩张,膀胱输尿管返流明显,肾脏体积和质量增加(P<0.001),肾实质变薄(P<0.0001);组织病理学检查可见肾小球萎缩,肾小管扩张,小管间质炎细胞浸润,肾小球基底膜增生,间质纤维化明显;Western blot、免疫荧光和免疫组化分别测得肾组织中波形蛋白、PCNA、α-SMA的表达水平均升高(P<0.0001)。结论小鼠行PBOO术后,膀胱、输尿管、肾脏均发生明显形态改变,并出现返流性肾纤维化样损害,可以作为研究膀胱出口梗阻导致的肾纤维化病理改变机制及治疗措施的动物模型。

Objective To establish an animal model of reflux renal damage through bladder outlet obstruction.Methods Sixty male C57 BL/6 mice aged 6-8 weeks were randomly assigned to a control group,a sham operation group,and a partial bladder outlet obstruction(PBOO)group,with 20 mice in each group.Laparotomy were performed on the PBOO mice under anesthesia in order to separate the bladder necks and to perform guided partial ligation of the bladder neck with a metal rod of 0.3 mm diameter.Mice in the sham operation group had laparotomy and had their bladder necks separated without ligation.The control group did not receive any treatment.7 days after the surgery,12 surviving mice were randomly selected from each group to observe the general changes of the bladder,ureter,renal pelvis and kidney.Retrograde urography was performed through the bladder.Kidney tissues were extracted for histopathological analysis.The expression levels of Vimentin,proliferating cell nuclear antigen(PCNA)andα-smooth muscle actin(α-SMA)were examined with Western blot,immunohistochemistry and immunofluorescence staining tests,respectively.Results Compared with the control and sham operation group,the bladder,ureter,and renal pelvis of the mice in the PBOO group were significantly enlarged,vesicoureteral reflux was more obvious,the kidney volume and mass increased(P<0.001),and renal parenchyma became thinner(P<0.0001).Histopathological staining showed glomerular atrophy,renal tubule expansion,tubulointerstitial inflammatory cell infiltration,glomerular basement membrane hyperplasia and obvious interstitial fibrosis.Western blot,immunofluorescence and immunohistochemistry staining showed that the expression levels of Vimentin,PCNA andα-SMA in kidney tissue were elevated(P<0.0001).Conclusion After PBOO,the bladder,ureter,and kidney of the mice showed obvious morphological alteration and presented reflux renal fibrosis-like damage.This can be used as an animal model to study the pathological alteration mechanism and therapeutic measures of renal fibrosis caused by bladder outlet obstruction.