A Murine Model of Irreversible and Reversible Unilateral Ureteric Obstruction

Summary

The murine model of irreversible unilateral ureteric obstruction (UUO) is presented together with the model of reversible UUO in which the ureteric obstruction is relieved by anastomosis of the severed ureter into the bladder. These models enable the study of renal inflammation and scarring as well as tissue remodeling.

Abstract

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive nephropathy induced by unilateral ureteric obstruction (UUO), which can either be irreversible (UUO) or reversible (R-UUO). In the irreversible UUO model, the ureter may be obstructed for variable periods of time in order to induce increasingly severe renal inflammation and interstitial fibrotic scarring. In the reversible R-UUO model the ureter is obstructed to induce hydronephrosis, tubular dilation and inflammation. After a suitable period of time the ureteric obstruction is then surgically reversed by anastomosis of the severed previously obstructed ureter to the bladder in order to allow complete decompression of the kidney and restoration of urinary flow to the bladder. The irreversible UUO model has been used to investigate various aspects of renal inflammation and scarring including the pathogenesis of disease and the testing of potential anti-inflammatory or anti-fibrotic therapies. The more challenging model of R-UUO has been used by some investigators and does offer significant research potential as it allows the study of inflammatory and immune processes and tissue remodeling in an injured and scarred kidney following the removal of the injurious stimulus. As a result, the R-UUO model offers investigators the opportunity to explore the resolution of kidney inflammation together with key aspects of tissue repair. These experimental models are of relevance to human disease as patients often present with obstruction of the renal tract that requires decompression and are commonly left with significant residual kidney impairment that has no current treatment options and may lead to eventual end stage kidney failure.

Introduction

The overall aim of the experimental model described here is to induce obstructive nephropathy by unilateral ureteric obstruction (UUO), which can either be irreversible (UUO) or reversible (R-UUO). A simple irreversible model of UUO is presented in which the left ureter is permanently obstructed by ligation with a suture or by the application of a ligating clip. This results in marked dilatation of the ureter together with reduced renal blood flow and glomerular filtration. Renal histology demonstrates tubular dilatation and increasingly severe interstitial renal inflammation and fibrosis. Irreversible UUO is a useful model and has been adopted by many researchers in....

Protocol

General Guidance: Animal experiments were performed in accordance with the guidelines and regulations imposed by the Animals (Scientific Procedures) Act 1986. This protocol and the accompanying video protocol are for both a standard UUO and a R-UUO, which can be performed on many mouse strains. In the accompanying video, both procedures are performed on male C57BL/6 mice aged 8 weeks. The data presented in the representative results section were obtained from male FVB/n mice.

NOTE: This protocol and accompanying video details how to perform a standard UUO and R-UUO utilizing the left ureter, however the same techniques can easily be applied....

Results

The appearance of the kidney changes markedly following ureteric obstruction and it becomes paler and tense to palpation with time (Figure 1). There is increasing dilatation of the ureter proximal to the obstruction and the renal pelvis. The kidney becomes increasingly atrophic as the duration of obstructive nephropathy increases with prolonged obstruction resulting in a marked thinning of the renal cortex and medulla. Following the reversal of the ureteric obstruction, the colour of the kidney becomes d.......

Discussion

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. The R-UUO model is of relevance to human disease as patients often present with obstruction of the renal tract secondary to prostatic hypertrophy, posterior urethral valves etc. that requires decompression with patients commonly left with significant residual kidney impairment that has no current treatment options and may eventually lead to end stage kidney disease.^8,9 The models detailed here enable .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Blunt Dissecting Scissors	Fine Science Tools	14072-10
Spring Scissors – straight	Fine Science Tools	15000-10
Toothed forceps	Fine Science Tools	11021-12
Angled forceps x 2	Fine Science Tools	00649-11
Straight forceps	Fine Science Tools	00632-11
Colibri 3 cm wire retractor	Fine Science Tools	17000-03
Castroviejo needle holder with lock	Fine Science Tools	12565-14
Wound clip applicator	Fine Science Tools	12031-07
7 mm wound clips	Fine Science Tools	12032-07
Castroviejo micro needle holder with lock	Fine Science Tools	12060-01
OPMI pico microscope	Carl Zeiss	S100
Heat electronic pad	Cozee Comfort	n/a
6/O silk braided suture	Harvard Apparatus	72-3287
9/O Dafilon (polyamide) suture	B-Braun	G1111434
5/O braided silk suture	Harvard Apparatus	51-7680
Regular bevel needle, 1 inch, 21G	Becton, Dickinson and Company	305175
1 ml syringe slip tip	Becton, Dickinson and Company	300184
Wypall paper swabs	Kimberley-Clark	L40	Sterilised (Autoclave)
Cotton wool buds	Johnson and Johnson	n/a	Sterilised (Autoclave)
Plain drapes	Guardian	CB03	Sterilised (Autoclave)
Soft wall silicone rubber tubing			Silicone tubing - internal diameter 1.0 mm; external diameter 2.0 mm; wall thickness 0.6 mm
(Lacri-Lube) White soft paraffin 57.3%, mineral oil 42.5% and lanolin alcohols 0.2%	Allergan Ltd	21956GB10X
(Videne) Povidone-iodine 10%	Ecolab Ltd	PL 04509/0041
(Vetalar V) Ketamine hydrochloride	Pfizer Animal Health	Vm 42058/4165	100mg/ml solution
(Domitor) Medetomidine hydrochloride	Orion Pharma	Vm 06043/4003	1mg/ml
(Vetergesic) Bupernorphine hydrochloride	Alsto Animal Health	Vm 00063/4002	0.3mg/ml
(Antisedan) Atipamezole hydrochoride	Orion Pharma	Vm 06043/4004	5mg/ml
(Adept) 4% Icodextrin	Baxter		Adhesion reduction solution
NaCl 0.9%	Baxter	FKE1323