Partial unilateral ureteral obstruction in rats

Abstract

This review comprises an overview of the current knowledge on experimental partial unilateral ureteral obstruction (PUUO) and a summary of our latest original experimental PUUO studies in rats. Neonatal PUUO is the type of obstruction that is most often encountered in pediatric clinical practice. However, the pathogenesis of PUUO is still incompletely understood. Most of our knowledge on PUUO has been derived from experimental studies in a variety of animal models. Although progress has been made, the natural history of congenital hydronephrosis is still incompletely described. The effects on kidney functions of long-term urinary tract obstruction, especially PUUO, have been less intensively studied. Recently, we created models with mild and severe PUUO in young rats by embedding the upper one fourth or the upper two thirds of the left ureter into the psoas muscle, respectively. Thereafter, the technique was used to create mild and severe PUUO in newborn rats and magnetic resonance imaging studies showed that both mild and severe obstruction caused a time-dependent decrease in renal blood flow. Compensatory increase in total kidney volume and renal vein blood flow in contralateral non-obstructed kidneys was not detectable when functional deterioration in the partially obstructed kidneys was present. Finally, we investigated the dynamic changes in renal relative signal intensity (RSI) of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) using magnetic resonance imaging in rats with partial, complete unilateral ureteral obstruction and sham-operated controls. The results showed that changes in Gd-DTPA RSI are compatible with the known physiological and anatomical changes in kidneys in response to ureteral obstruction and useful for distinguishing an obstructed from a non-obstructed collecting system and also for differentiating a partially obstructed from a completely obstructed collecting system.

Role of Stat3 Signaling in Control of EMT of Tubular Epithelial Cells During Renal Fibrosis

“…Ten mice received UUO and 10 mice were sham treated as controls. For UUO, mice received left ureteral ligation with 6-G silk suture, as has been previously described [12]. After surgery, mice were sacrificed at 3 or 14 days after surgery.…”

Regulation of Renal Fibrosis by Macrophage Polarization

“…The crosstalk between TGFβ1 and BMP7 coordinates the repair and recovery of the injured kidney [12,13,14]. The Unilateral ureteral obstruction (UUO) model is a well-established experimental obstructive nephropathy model for generating progressive renal fibrosis in rodents [15,16]. …”

Increased TGF-α and EGF Receptor mRNA Expression in Response to Neonatal Unilateral Partial Ureter Obstruction in Rats

“…Clinically most congenital obstructions are partial and chronic [27]. In the severely obstructed kidney in humans, the hydronephrosis progressed significantly with time compared with the mildly obstructed kidney [27]. It is therefore more relevant to use the partial rather than CUUO on the animal model setting in order to investigate this pathological entity.…”

“…Thus, this model may not be able to mimic the clinical situation. Clinically most congenital obstructions are partial and chronic [27]. In the severely obstructed kidney in humans, the hydronephrosis progressed significantly with time compared with the mildly obstructed kidney [27].…”