The preventive effect of a free radical scavenger on oxidative stress after the relief of partial bladder outlet obstruction in a rat model

Abstract

AimsTo investigate the effect of a free radical scavenger (tempol) after relief of partial bladder outlet obstruction (pBOO) on bladder function in a rat model.MethodspBOO was induced in 50 eight-week-old female Sprague-Dawley rats and relieved 3 weeks later. The rats were divided randomly into 5 groups: sham-operated, tempol-treated for 1 week (Treat-1w) or 3 weeks (Treat-3w), and no treatment for 1 week (nonTreat-1w) or 3 weeks (nonTreat-3w). Awaken cystometrograms were obtained 1 or 3 weeks after relief according to the grouping. The bladders were isolated and weighed. H&E, Masson’s trichrome and TUNEL staining were used to analyze histological changes. The oxidative stress assessed using malondialdehyde. The expression of beta-3 adrenoreceptor was examined by Western blotting.ResultsThe tempol-treated groups exhibited a significant decrease in the number of non-voiding contractions per voiding cycle (nonTreat-1w vs. Treat-1w, 1.18±0.82 vs. 0.36±0.40, P = 0.010; nonTreat-3w vs. Treat-3w, 1.51±0.69 vs. 0.23±0.25, P = 0.002). The thickness and collagen fiber deposition of the detrusor muscle layer was significantly decreased in the treated groups. Apoptosis detected was mainly observed in the urothelial cell layer, although the rate of apoptosis was significantly decreased in the treated groups (48.9±3.36% vs. 32.7±11.10%, P = 0.024; 25.8±4.67% vs. 15.7±9.83%, P = 0.314). The tempol-treated groups showed significant decreases in the MDA concentrations at both 1 and 3 weeks after relief. The expression of the beta-3 adrenoreceptor was increased in the tempol-treated rats.ConclusionsIschemic reperfusion injury after relief of pBOO caused histological and functional changes in the bladder. Free radical scavenger treatment prevented this oxidative stress.

Effect of Electroacupuncture on Bladder Dysfunction via Regulation of MLC and MLCK Phosphorylation in a Rat Model of Type 2 Diabetes Mellitus

“…We observed that the bladder wall of the DM group was significantly thicker than that of the control group. This is mainly due to bladder detrusor smooth muscle layer hypertrophy [ 48 ]. Furthermore, the bladder wall thickness of the EA group was significantly lower than that of the sham EA group.…”

A Review of Oxidative Stress and Urinary Dysfunction Caused by Bladder Outlet Obstruction and Treatments Using Antioxidants

“…Tempol, which is a free radical scavenger, was recently found to prevent BOO-induced thickening of collagen fibers and deposition of these fibers in the detrusor muscle layer via suppression of oxidative stress in a rat model [88]. In this model, the thickness and deposition of collagen fibers in the detrusor muscle layer in rats treated with tempol were significantly less than those in rats that were untreated, and the number of non-voiding contractions per voiding cycle decreased with tempol treatment.…”

“…In this model, the thickness and deposition of collagen fibers in the detrusor muscle layer in rats treated with tempol were significantly less than those in rats that were untreated, and the number of non-voiding contractions per voiding cycle decreased with tempol treatment. In addition, levels of the oxidative stress marker MDA in bladder tissues were significantly lower in tempol-treated rats than in untreated ones [88].…”

Changes in urethral smooth muscle and external urethral sphincter function with age in rats

“…The intercontraction interval (ICI), pressure threshold, baseline pressure, amplitude voiding pressure, and the number of non‐voiding contractions (NVCs) were measured during the final 30 min. NVCs were defined as small‐amplitude bladder contractions without voiding that were greater than 3 cmH 2 O (Choo et al., 2018). During the final bladder contraction, bladder infusion was stopped and the residual urine volume was measured by withdrawing intravesical fluid through the catheter by gravity and compressing the bladder.…”