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Updated: Oct 17, 2025

An Immature Murine Model of Reversible Unilateral Ureteral Obstruction
Published on: April 4, 2025
[Establishment of an Animal Model of Vesicoureteral Reflux Renal Injury through Partial Bladder Outlet Obstruction]
Zhao-Ying Wang1, Zhao-Xia Zhang1, Li-Ming Jin1
1Key Laboratory of Children Urogenital Development and Tissue Engineering, Key Laboratory of Children's Development and Disorders of the Ministry of Education, National Clinical Research Center for Children's Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing 400014, China.
Objective:
To establish an animal model of reflux renal damage through bladder outlet obstruction.
Methods:
Sixty male C57BL/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) and α-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<0.000 1). 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 and α-SMA in kidney tissue were elevated ( P<0.000 1).
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.

