Login to Access Video or Poster Abstract: MP94-13
Sources of Funding: none

Introduction

In patients with BPH, de novo UI developed in 7.1-44.0% after HoLEP. Urodynamic involuntary detrusor contraction (IDC) was often observed in these patients. Ischemia reperfusion injury that occurs after de-obstruction has been proposed as a main cause of post-operative IDC. We investigated the effect of free radical scavenger (tempol) after relief of partial bladder outlet obstruction (pBOO) on bladder function in a rat model.

Methods

Eight-week-old female Sprague Dawley of 40 rats (200-250g) were induced pBOO, and relieved it 3 weeks later. Rats were divided randomly 4 groups: tempol treated for 1 week (T1 group) and 3 weeks (T3 group), and no treated for 1 week (nT1 group) and 3 weeks (nT3 group). Cystometrograms were obtained in unanesthetized, unrestrained rats in metabolic cages at 1 or 3 weeks after relief, according to grouping, respectively. After completion of the investigation, the bladder was isolated and weighted. H&E, Masson trichrome and TUNEL staining were used to analyze the change of histology of the bladder.

Results

Tempol treated groups decreased significantly in the number of IDC per voiding cycle (nT1 vs. T1, 1.18±0.82 vs. 0.36±0.40, P=0.010; nT3 vs. T3, 1.51±0.69 vs. 0.23±0.25, P=0.002). In the H&E staining, treated groups decreased significantly in thickness of the detrusor muscle layer (nT1 vs. T1, 1164.17±190.58 vs. 776.45±140.78, P<0.001; nT3 vs. T3, 905.82±161.16 vs. 726.26±162.76, P=0.043). In the Masson Chrome staining, the rates of collagen fiber were significantly lower in the treated groups. Apoptosis detected by TUNEL was observed in the urothelial cell layer mainly. The treated groups decreased significantly in the rate of apoptosis in urothelial cell layer (nT1 vs. T1, 48.9±3.36% vs. 32.7±11.10%, P=0.024; nT3 vs. T3, 25.8±4.67% vs. 15.7±9.83%, P=0.314).

Conclusions

Ischemia reperfusion injury that occurred after de-obstruction caused histologic and functional change of the bladder. Free radical scavenger could prevent this oxidative stress.

Funding

none