Effects of coenzyme Q10 on bladder dysfunction induced by chronic bladder ischemia in a rat model

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer’s disease, and Parkinson’s disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.

CoQ10 ameliorates monosodium glutamate-induced alteration in detrusor activity and responsiveness in rats via anti-inflammatory, anti-oxidant and channel inhibiting mechanisms

Background

Competent detrusor muscles with coordinated contraction and relaxation are crucial for normal urinary bladder storage and emptying functions. Hence, detrusor instability, and subsequently bladder overactivity, may lead to undesirable outcomes including incontinence. Multiple mechanisms may underlie the pathogenesis of detrusor overactivity including inflammation and oxidative stress. Herein, we tested the possibility that CoQ10 may have a potential therapeutic role in detrusor overactivity.

Methods

Forty adult male Wistar albino rats weighing 100-150 g were used in the present study. Rats were divided (10/group) into control (receiving vehicles), monosodium glutamate (MSG)-treated (receiving 5 mg/kg MSG daily for 15 consecutive days), MSG + OO-treated (receiving concomitantly 5 mg/kg MSG and olive oil for 15 consecutive days), MSG + CoQ10-treated (receiving concomitantly 5 mg/kg MSG and 100 mg/kg CoQ10 daily for 15 consecutive days) groups.

Results

MSG resulted in significant increase in bladder weight and sensitised the bladder smooth muscles to acetylcholine. MSG has also resulted in significant increase in bladder TNF-α, IL-6, malondialdehyde, nerve growth factor and connexion 43, with significant decrease in the antioxidant enzymes superoxide dismutase and catalase. Olive oil had no effect on MSG induced alterations of different parameters. Treatment with CoQ10 has resulted in a significant restoration of all the altered parameters.

Conclusion

Taken together, our results suggest that CoQ10 antagonizes the deleterious effects of MSG on detrusor activity. We propose that CoQ10 could be a therapeutic strategy targeting urinary bladder dysfunction.

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

Urinary dysfunction is a common pathological condition that can significantly decrease the quality of life. Bladder outlet obstruction (BOO) is a major cause of urinary dysfunction, and various lower urinary tract diseases including benign prostatic hyperplasia and urethral stricture disease cause BOO. According to the results of a variety of animal experiments on partial BOO (PBOO), there is a general agreement that ischemic conditions and repeated ischemia/reperfusion of the bladder are closely associated with BOO-induced bladder damage, and that increased oxidative stress by ischemia/reperfusion plays a crucial role in the pathological mechanisms underlying urinary dysfunction. Changes in biomarkers of oxidative stress in PBOO animal models support this association between oxidative stress and urinary dysfunction. Oxidative stress is defined as an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidants. Therefore, organizing the knowledge on the state of oxidative stress, changes in biomarkers, and biological roles of antioxidants in systemic and bladder tissues is essential to understand the detailed pathological characteristics of the urinary dysfunction caused by PBOO. Furthermore, information on drugs and supplements that have antioxidant effects is important for defining treatment strategies for urinary dysfunction with PBOO. In this review, we paid special attention to the following three issues; (1) changes in oxidative stress, including its biomarkers, (2) antioxidant status, and (3) previous reports on treatment strategies involving agents with antioxidative activity for urinary dysfunction caused by BOO. In particular, we provide systematic information on the detailed mechanisms underlying the antioxidative effects of agents used to treat PBOO. In addition, we show present research issues and research limitations, as well as suggest possible future antioxidant treatment strategies for patients with PBOO.

Chronic high-fat diet decreased detrusor mitochondrial respiration and increased nerve-mediated contractions

AIMS

To assess the impact of chronic high-fat diet (HFD) on behavioral voiding patterns, detrusor contractility, and smooth muscle mitochondrial function in male mice.

MATERIALS AND METHODS

Male C57BL/6J mice (6 weeks) were fed a control or HFD for 20 weeks. Bladder function was assessed by void spot assays. Bladders were collected and detrusor contractility to carbachol (10^-9 -10^-5  M), and electrical field stimulation (EFS, 0.5-32 Hz) in the presence and absence of atropine was measured. Homogenized detrusor samples were placed in oxygraphs to assess the rate of oxygen consumption of the mitochondria within the detrusor in the presence of different substrates. Mitochondrial hydrogen peroxide (H₂ O₂ ) emission was measured fluorometrically. Detrusor citrate synthase activity was measured via enzyme activity kit and Western blots assessed the electron transport chain (ETC) protein content.

RESULTS

HFD significantly increased body weight, adiposity, and blood glucose levels. HFD mice demonstrated increased voiding frequency and increased EFS-induced detrusor contractility. There were no changes in detrusor relaxation or cholinergic-medicated contraction. Mitochondrial respiration was decreased with HFD and H₂ O ₂ emission was increased. The relative amount of mitochondria in the detrusor was similar between groups. However, ETC complexes V and III were increased following HFD.

CONCLUSIONS

Chronic HFD increased adiposity, lead to more frequent voiding, and enhanced EFS-mediated detrusor contractions. Mitochondrial respiration was decreased and H₂ O ₂ emission increased following HFD. Further research is required to determine if alterations in mitochondrial function could play a role in the development of HFD-induced bladder dysfunction.

Improvement of Persistent Detrusor Overactivity through Treatment with a Phytotherapeutic Agent (WSY-1075) after Relief of Bladder Outlet Obstruction

Purpose

Many patients with benign prostatic hyperplasia need treatment for remaining storage symptoms after surgery. Therefore, we evaluated the effect of the phytotherapeutic agent WSY-1075 on persistent detrusor overactivity (DO) after the relief of bladder outlet obstruction (BOO).

Materials and Methods

Rats were assigned to 3 groups: control (n=6), persistent DO (n=6), and persistent DO treated with the phytotherapeutic agent WSY-1075 (n=6). Persistent DO after relief of partial BOO was generated in the rat model, and 6 of the rats with this condition were orally administered WSY-1075. After 4 weeks of administration, cystometry was performed. Additionally, 8-hydroxy-2-deoxyguanosine and superoxide dismutase were measured to evaluate oxidative stress in the bladder. Pro-inflammatory cytokines, such as interleukin-8 and tumor necrosis factor-α, were analyzed, as were the M2 and M3 muscarinic receptors of the bladder.

Results

Significantly increased contraction pressure and a decreased contraction interval were observed in the persistent DO group after relief of BOO. Moreover, oxidative stress, pro-inflammatory cytokines, and M3 muscarinic receptors were significantly increased. After treatment with WSY-1075, significantly reduced DO was observed by cystometry in comparison with the persistent DO group. Additionally, significantly decreased levels of oxidative stress, pro-inflammatory cytokines, and M3 muscarinic receptors in the bladder were observed after treatment with WSY-1075.

Conclusions

Treatment with WSY-1075 improved persistent DO after the relief of BOO mediated by antioxidative and anti-inflammatory effects. Further studies are necessary to identify the exact mechanism of the treatment effect of WSY-1075.

LUTS in pelvic ischemia: a new concept in voiding dysfunction

Lower urinary tract symptoms (LUTS) are a group of voiding symptoms affecting both genders as they age. Traditionally, LUTS in men were commonly attributed to bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE). It was later shown that, in approximately one-third to more than one-half of cases, LUTS in men are not associated with BOO. Urodynamic changes in the male bladder and symptom scores in aging men were found to be identical to their age-matched female counterparts. These observations suggested that LUTS in the elderly do not necessarily relate to BOO and may result from local changes in bladder muscle, nerves, and blood vessels. However, aging factors predisposing to bladder dysfunction and LUTS remain unknown. Growing evidence suggests that aging-associated pelvic ischemia may be a primary factor in the development of nonobstructed nonneurogenic overactive bladder and LUTS. First identified in experimental models and later in clinical studies, pelvic ischemia has been shown to compromise the lower urinary tract structure and lead to dysfunction. Structural and functional consequences of bladder and prostate ischemia have been documented in animal models. Clinical studies have shown that bladder and prostate blood flow decreases with aging. The severity of LUTS in elderly patients correlates with the degrees of bladder ischemia. LUTS improvement with α blockers has been associated with increased bladder blood flow. Pelvic ischemia may be an independent factor in nonobstructed nonneurogenic bladder instability and LUTS. Further research into the pathophysiology of LUTS in pelvic ischemia may lead to better management of this problem in the elderly population.

Drug Concentration in Rat Plasma, Bladder, and Prostate After Mirodenafil Administration in a Chronic Pelvic Ischemia Model

OBJECTIVE

To evaluate the distribution of a daily phosphodiesterase type 5 inhibitor dose (mirodenafil) in rat plasma and bladder and prostate tissue in a model of atherosclerosis-induced chronic pelvic ischemia.

METHODS

Thirty-two 18-week-old male Sprague Dawley rats were divided into two groups. Group I (n = 16) comprised a chronic pelvic ischemia model treated with mirodenafil and group II (n = 16) comprised a sham-operated model also treated with mirodenafil. The mirodenafil concentrations in each organ were measured at specific time points after 14 days of daily mirodenafil administration. The drug distribution ratio of group I to group II of each organ was measured, and the bladder tissue-to-plasma and prostate tissue-to-plasma ratios were calculated.

RESULTS

The mean drug concentration in the bladder of the rats in group I did not differ significantly from that of group II after mirodenafil administration. In the prostate, the mean drug concentration of group I was significantly higher than that of group II at 1 and 4 hours after drug administration. The drug concentration was higher in the bladder tissue than in the prostate tissue and the bladder tissue-to-plasma ratio was significantly higher than the prostate tissue-to-plasma ratio.

CONCLUSION

Our results suggest that mirodenafil levels might be sufficient in the target tissue after daily treatment in an ischemia-induced aging model. Considering the difficulties of tissue distribution study in human subjects, the results of this investigation provided meaningful evidence of the application of daily doses of mirodenafil for treating lower urinary tract symptoms in an aging population.

Mirodenafil prevents bladder dysfunction induced by chronic bladder ischemia in rats

Purpose:

To investigate the protective effect of mirodenafil on bladder function in a rat model of chronic bladder ischemia (CBI).

Methods:

Twenty-four Sprague-Dawley rats were randomized to three groups: untreated, sham-operated rats (control group); untreated, CBI model rats (CBI group); and CBI rats treated daily with 4 mg/kg mirodenafil (CBI+mirodenafil group). The CBI and CBI+mirodenafil groups underwent endothelial injury to the iliac arteries and were fed a 2% cholesterol diet after injury. Four weeks after surgery, the CBI+mirodenafil group started daily treatment with mirodenafil for four weeks. Eight weeks after surgery, continuous in vivo cystometry and in vivo organ bath studies of detrusor muscle strips were performed.

Results:

in vivo cystometry revealed that the rats in the CBI group had a significantly higher micturition frequency, lower bladder capacity, and lower compliance than the rats in the control and CBI+mirodenafil groups. The detrusor muscle strip study showed that the magnitude of the carbachol-induced contractile response was significantly lower in the CBI group compared to either the control or CBI+mirodenafil group. Addition of daily mirodenafil after induction of CBI decreased the contractile response, compared to untreated CBI rats. CBI induced submucosal fibrosis and degenerative changes in bladder walls, which was reversed by the addition of mirodenafil.

Conclusions:

Daily treatment with mirodenafil showed protective effects against bladder dysfunction resulting from CBI in rats.

Metabolic syndrome and lower urinary tract symptoms

Recently, clinical and epidemiologic data indicating the involvement of metabolic syndrome (MetS) in the pathogenesis and progression of lower urinary tract symptom (LUTS)/benign prostatic hyperplasia (BPH) are reported. This review evaluates the reports on the influence of MetS in the development and progression of LUTS/BPH, and discusses possible clinical implications for the management and treatment of this disease. Recent studies on the epidemiological relationship between MetS and LUTS hypothesize that MetS may be associated with an overactivity of the autonomic nervous system for which hyperinsulinemia, a key element of the MetS, might be responsible. An alternative explanation is that LUTS are associated with chronic ischemia of pelvis resulting from atherosclerotic changes in blood vessels, which leads the production of reactive oxygen species, which can damage the bladder detrusor. Control of autonomic nervous system overactivity and control of chronic bladder ischemia have potential as new targets for LUTS treatment. Studies suggest an association of MetS with LUTS/BPH, although further research is needed to understand how MetS influences LUTS/BPH. MetS should be considered a new domain in basic and clinical research in patients with LUTS/BPH and as a target for treatment.

Effects of medical therapy or surgery on prostatic and bladder resistive indices in patients with benign prostatic hyperplasia

INTRODUCTION

The effects of medical therapy or surgery on bladder and prostatic resistive indices (RIs) in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) were evaluated in the present study.

PATIENTS AND METHODS

A total of 124 consecutive LUTS/BPH patients who were candidates for medical therapy (alfuzosin 10 mg once daily, n=66) or surgery (transurethral prostatectomy (TUR-P), n=58) were prospectively included. Baseline assessment of patients was performed with the International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), and prostatic and bladder RIs measured using power Doppler imaging (PDI). All patients were re-evaluated 3 months after treatment measuring the same parameters.

RESULTS

Following medical therapy, mean IPSS (17.2±5.1 vs. 8.3±5.3, p=0.0001), postvoiding residual (PVR) urine (80.0±80.5 vs. 40.3±38.6, p=0.0001), and prostatic RI (0.73±0.1 vs. 0.70±0.1, p=0.0001) were decreased, Qmax (13.7±4.2 vs. 16.9±5.9, p=0.0001) was increased, and bladder RI remained unchanged (0.70±0.1 vs. 0.70±0.1, p=0.68). Mean IPSS (25.3±5.6 vs. 6.0±4.5, p=0.0001), PVR urine volume (134.5±115.5 vs. 35.7±25.9, p=0.0001), and prostatic (0.78±0.1 vs. 0.67±0.04, p=0.0001) and bladder RIs (0.72±0.1 vs. 0.64±0.04, p=0.005) were decreased, and Qmax (8.0±4.5 vs. 17.2±8.2, p=0.0001) was increased after TUR-P.

CONCLUSIONS

Our results demonstrated that TUR-P decreased both prostatic and bladder RIs, while α-blocker therapy did not change bladder RI in the early posttreatment period in LUTS/BPH patients.

Pharmacological treatment of chronic pelvic ischemia

Epidemiological studies have shown that lower urinary tract symptoms, including overactive bladder, commonly occur in both men and women, with an age-related increase in both sexes. Vascular endothelial dysfunction and urological symptoms are common in the metabolic syndrome; they also occur during the human ageing process and are independent risk factors for the development of atherosclerosis and hypertension. Pelvic arterial insufficiency may lead to impaired lower urinary tract perfusion and play an important role in the development of bladder dysfunction such as detrusor overactivity and overactive bladder. It seems reasonable, but has not been definitely established clinically, that chronic ischemia-related bladder dysfunction will progress to bladder underactivity. Studies in experimental models in rabbits and rats have shown that pelvic arterial insufficiency may result in significant bladder ischemia with reduced bladder wall oxygen tension, oxidative stress, increased muscarinic receptor activity, ultrastructural damage, and neurodegeneration. Several types of drug may be able to prevent some of these changes. Even if the α1-adrenoceptor blocker, silodosin, the phosphodiesterase type 5 inhibitor, tadalafil, the β3-α1-adrenoceptor agonist, mirabegron, and the free radical scavenger, melatonin, were unable to prevent the development of neointimal hyperplasia and consequent luminal occlusion in animal models, they all exerted a protecting effect on urodynamic parameters, and on the functional and morphological changes of the bladder demonstrable in vitro. The different mechanisms of action of the drugs suggest that many factors are involved in the pathogenesis of chronic ischemia-induced bladder dysfunction and can be targets for intervention. Since several of the agents tested are used clinically and effectively for relieving lower urinary tract symptoms, the results from animal models of chronic bladder ischemia seem to have translational value. Animal models may be of relevance for designing clinical studies to demonstrate if a certain drug may prevent progression of ischemia-related functional and morphological bladder changes.