Ischemia, Hypoxia and Oxidative Stress in Bladder Outlet Obstruction and Bladder Overdistention Injury

Mechanisms of oxidative stress in interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is characterized by bladder and/or pelvic pain, increased urinary urgency and frequency and nocturia. The pathophysiology of IC/BPS is poorly understood, and theories include chronic inflammation, autoimmune dysregulation, bacterial cystitis, urothelial dysfunction, deficiency of the glycosaminoglycan (GAG) barrier and urine cytotoxicity. Multiple treatment options exist, including behavioural interventions, oral medications, intravesical instillations and procedures such as hydrodistension; however, many clinical trials fail, and patients experience an unsatisfactory treatment response, likely owing to IC/BPS phenotype heterogeneity and the use of non-targeted interventions. Oxidative stress is implicated in the pathogenesis of IC/BPS as reactive oxygen species impair bladder function via their involvement in multiple molecular mechanisms. Kinase signalling pathways, nociceptive receptors, mast-cell activation, urothelial dysregulation and circadian rhythm disturbance have all been linked to reactive oxygen species and IC/BPS. However, further research is necessary to fully uncover the role of oxidative stress in the pathways driving IC/BPS pathogenesis. The development of new models in which these pathways can be manipulated will aid this research and enable further investigation of promising therapeutic targets.

Enzyme-induced hypoxia leads to inflammation in urothelial cells in vitro

PURPOSE

To determine the contributions of different durations of hypoxia to NLRP3 inflammasome activation in urothelial cells and how ischemic changes in bladder tissues is an important chemical que that leads to pathological changes seen in BOO.

METHODS

A rat urothelial cell line (MYP3) was exposed to either a short duration (2 h) or long duration (6 h) of enzyme-induced hypoxia. Following exposure to a short duration of hypoxia, NO and ATP concentrations were measured from supernatant media and caspase-1 levels were measured from cell lysates. In a separate experiment, cells were fixed following hypoxia exposure and immunostained for HIF-1α stabilization.

RESULTS

Although short exposure of low oxygen conditions resulted in a hypoxic response in MYP3 cells, as indicated by HIF-1α stabilization and increased NO activity, NLRP3 inflammasome activation was not observed as caspase-1 activity remained unchanged. However, exposure of MYP3 cells to a longer duration of hypoxia resulted in an increase in intracellular caspase-1 activity. Furthermore, treatment with antioxidant (GSH) or TXNIP inhibitor (verapamil) attenuated the hypoxia-induced increase in caspase-1 levels indicating that hypoxia primarily drives inflammation through a ROS-mediated TXNIP/NLRP3 pathway.

CONCLUSION

We conclude that hypoxia induced bladder damage requires a duration that is more likely related to elevated storage pressures/hypoxia, seen in later stages of BOO, as compared to shorter duration pressure elevation/hypoxia that is encountered in normal micturition cycles or early in the BOO pathology where storage pressures are still normal.

Mechanisms involved in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox)-derived reactive oxygen species (ROS) modulation of muscle function in human and dog bladders

Roles of redox signaling in bladder function is still under investigation. We explored the physiological role of reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) in regulating bladder function in humans and dogs. Mucosa-denuded bladder smooth muscle strips obtained from 7 human organ donors and 4 normal dogs were mounted in muscle baths, and trains of electrical field stimulation (EFS) applied for 20 minutes at 90-second intervals. Subsets of strips were incubated with hydrogen peroxide (H2O2), angiotensin II (Ang II; Nox activator), apocynin (inhibitor of Noxs and ROS scavenger), or ZD7155 (specific inhibitor of angiotensin type 1 (AT1) receptor) for 20 minutes in continued EFS trains. Subsets treated with inhibitors were then treated with H2O2 or Ang II. In human and dog bladders, the ROS, H2O2 (100μM), caused contractions and enhanced EFS-induced contractions. Apocynin (100μM) attenuated EFS-induced strip contractions in both species; subsequent treatment with H2O2 restored strip activity. In human bladders, Ang II (1μM) did not enhance EFS-induced contractions yet caused direct strip contractions. In dog bladders, Ang II enhanced both EFS-induced and direct contractions. Ang II also partially restored EFS-induced contractions attenuated by prior apocynin treatment. In both species, treatment with ZD7155 (10μM) inhibited EFS-induced activity; subsequent treatment with Ang II did not restore strip activity. Collectively, these data provide evidence that ROS can modulate bladder function without exogenous stimuli. Since inflammation is associated with oxidative damage, the effects of Ang II on bladder smooth muscle function may have pathologic implications.

Effect of urinary retention on the surgical outcome of holmium laser enucleation of the benign prostatic hyperplasia

PURPOSE

To evaluate the effect of urinary retention (UR) on holmium laser enucleation of the prostate (HoLEP) in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms.

MATERIALS AND METHODS

A retrospective analysis of a prospective cohort of patients who underwent HoLEP between January 2010 and December 2016 was performed. The perioperative factors, including the International Prostate Symptom Score, Overactive Bladder Symptom Score, prostate-specific antigen, urodynamic study results, uroflowmetry results, transrectal ultrasound prostate volume, operative time, morcellation time, enucleation weight, and complications, were evaluated. Postoperative evaluation was performed at 2, 3, and 6 months.

RESULTS

Overall, 903 patients were identified. The mean age and follow-up were 68.3 years and 6 months, respectively. Among the patients, 135 (15.0%) patients had a history of acute UR (AUR), and 36 patients (4.0%) had chronic UR (CUR). The mean detrusor pressures at maximum flow were 64.4, 74.3, and 77.7 cmH₂O (p<0.001). The mean maximum flow rates (Qmax) were 7.6, 6.6, and 4.8 mL/s (p<0.001). Additionally, the mean bladder outlet obstruction indices were 49.5, 61.1, and 69.4 (p<0.001). The postoperative Qmax improved in all three groups. The mean postvoid residual volumes (PVRs) were 55, 75, and 333 mL preoperatively; 20, 29, and 66 mL at 2 weeks; 16, 23, and 45 mL at 3 months; and 15, 22, and 52 mL at 6 months (p<0.001).

CONCLUSIONS

Voiding symptoms, PVR, and Qmax of BPH patients with preoperative AUR and CUR significantly improved after Ho-LEP, similar to those without preoperative UR.

Effects of Lycopene Attenuating Injuries in Ischemia and Reperfusion

Tissue and organ ischemia can lead to cell trauma, tissue necrosis, irreversible damage, and death. While intended to reverse ischemia, reperfusion can further aggravate an ischemic injury (ischemia-reperfusion injury, I/R injury) through a range of pathologic processes. An I/R injury to one organ can also harm other organs, leading to systemic multiorgan failure. A type of carotenoid, lycopene, has been shown to treat and prevent many diseases (e.g., rheumatoid arthritis, cancer, diabetes, osteoporosis, male infertility, neurodegenerative diseases, and cardiovascular disease), making it a hot research topic in health care. Some recent researches have suggested that lycopene can evidently ameliorate ischemic and I/R injuries to many organs, but few clinical studies are available. Therefore, it is essential to review the effects of lycopene on ischemic and I/R injuries to different organs, which may help further research into its potential clinical applications.

Vibegron inhibits enhanced spontaneous contractions induced by anoxia/reoxygenation in isolated whole bladder from rats

It has been recently proposed that repeated bladder ischemia/reperfusion induced by chronic pelvic ischemia may lead to detrusor overactivity, followed by lower urinary tract symptoms. Vibegron is a selective β₃-adrenoceptor agonist approved for the treatment of overactive bladder. Several studies have tested β₃-adrenoceptor agonists using animal models with detrusor overactivity related to bladder ischemia/reperfusion. However, whether β₃-adrenoceptor agonists directly affect ischemia/reperfusion-evoked detrusor overactivity is unclear. Therefore, we examined whether bladder anoxia/reoxygenation could enhance spontaneous bladder contractions (SBCs) and investigated the effect of vibegron on enhanced SBCs. Isolated whole bladders from rats were incubated with Krebs solution aerated with 95% N₂ + 5% CO₂ for 5 h (anoxia). Subsequently, the bathing solution was replaced with an oxygen-saturated solution (reoxygenation). Anoxia/reoxygenation caused enhancement of the amplitude but not the frequency of SBC compared with that before reoxygenation. Vibegron (0.3-30 μM) inhibited this increase in SBC amplitude, but not the frequency, in a dose-dependent manner. The inhibitory effect of vibegron was not affected by pretreatment with the adenylyl cyclase inhibitor SQ22536 (100 μM) or protein kinase A inhibitor KT5720 (1 μM) and was not accompanied by considerable changes in cyclic adenosine monophosphate (cAMP) content in the bladder. In contrast, the large conductance potassium channel inhibitor iberiotoxin (100 nM) suppressed the inhibitory effect of vibegron. These results suggest that bladder ischemia/reperfusion induces SBC enhancement and vibegron directly inhibits detrusor overactivity via the large conductance potassium channel, which involves β₃-adrenoceptor, rather than the cAMP signaling pathway.

Adipose-Derived Stem Cells and Their Derived Microvesicles Ameliorate Detrusor Overactivity Secondary to Bilateral Partial Iliac Arterial Occlusion-Induced Bladder Ischemia

(1) Background: We established a new bladder ischemia rat model through bilateral partial iliac arterial occlusion (BPAO) and investigated the therapeutic effect of adipose-derived stem cells (ADSCs) and ADSC-derived microvesicles (MVs); (2) Methods: The study included four groups: (1) sham, (2) BPAO, (3) BPAO + ADSCs, and (4) BPAO + ADSC-derived MVs. Female Wistar rats with BPAO were injected with ADSCs or ADSC-derived MVs through the femoral artery. Doppler flowmetry and real-time laser speckle contrast imaging were performed to quantify blood flow in the common iliac arteries and bladder microcirculation. A 24-h behavior study and transcystometrogram were conducted after 2 weeks. Bladder histology, immunostaining, and lipid peroxidation assay were performed. The expressions of P2X2, P2X3, M2, and M3 receptors and nerve growth factor (NGF) were evaluated; (3) Results: BPAO significantly reduced bladder microcirculation, intercontraction interval (ICI), and bladder volume and increased the amplitude of nonvoiding contraction, neutrophil infiltration, and malondialdehyde and NGF levels. ADSCs and ADSC-derived MVs significantly ameliorated these effects. The results of Western blot showed that the BPAO group exhibited the highest expression of M3 and P2X2 receptors. ADSCs significantly attenuated the expressions of M2 and P2X2 receptors. ADSC-derived MVs significantly attenuated the expressions of M3 and P2X2 receptors; (4) Conclusions: ADSCs and ADSC-derived MVs ameliorated the adverse effects of BPAO including bladder overactivity, bladder ischemia, and oxidative stress. Inflammation, muscarinic signaling, purinergic signaling, and NGF might be involved in the therapeutic mechanism.

Expression of Toll-Like Receptors in the Animal Model of Bladder Outlet Obstruction

Introduction

Bladder outlet obstruction (BOO) occurs in more than 20 percent of the adult population and may lead to changes in the structure and function of the bladder. The main objective of the study was to evaluate the expression of Toll-like receptor 4 (TLR 4) and Toll-like receptor 9 (TLR 9) in the animal model of BOO as potential triggers of the inflammation phase in the bladder. In addition, the modulating effect of alpha-1 adrenergic antagonist (tamsulosin) on TLR 4 and TLR 9 expression and inflammatory markers was assessed. Material and Methods. Thirty-two male, 9-week-old Sprague Dawley rats were randomly divided into 4 groups: SOP—sham-operated rats with a placebo (water); SOB—sham-operated rats with an alpha-1 adrenergic antagonist; BOOP—rats with BOO and a placebo; and BOOB—rats with BOO and an alpha-1 adrenergic antagonist. The rats were given a placebo or alpha-1 adrenergic antagonist for 15 days. Next, urine and the bladder were collected from the rats for histopathological and biochemical study.

Results

Histopathological analysis showed chronic inflammation without acute inflammation in the bladder. TLR 4 showed positive cytoplasmic reactivity in the urothelium and the smooth muscles of the bladder. TLR 9 showed positive cytoplasmic reactivity only in the urothelium. BOO caused an increase in TLR 4 and TLR 9 expression. Furthermore, treatment with an alpha-1 adrenergic antagonist had no significant effect on TLR 4 and TLR 9 expression in rats with BOO. BOO caused a significant increase in urine concentration of interleukin 6 (IL-6), while alpha-1 antagonist reduced the urine concentration of IL-6 and the concentration of interleukin 18 (IL-18).

Conclusions

The results suggest the participation of TLR 4 and TLR 9 receptors in the induction of inflammation in the bladder, which is the first phase in the development of pathophysiological changes in BOO.

Evaluation of oxidative stress in bladder in urethral injuries: an experimental model in rats

Background: The aim of this study is to determine the changes of some oxidative stress parameters following an experimental urethral injury.

Materials and Methods: 24 Wistar-Albino male rats were used and 18 of them were exposed to urethral injury. Total oxidant status (TOS) and total antioxidant capacity (TAC) values in bladder and penile tissues and sera of rats during creation and healing stages of injury (control, day-1, 7 and 21) were examined and evaluated histopathologically.

Results: TOS levels in both tissue and serum groups increased nearly 4x fold in first day following injury. On the seventh day, TOS levels of bladder and penile tissue showed a nearly 50% decrease according to first day (p=0.005; p=0.025, respectively). At the end of third week, while bladder TOS levels decreased to control values, penile tissue TOS levels remained at high levels. The bladder TAC values mildly increased in first day (p=0.026) and then returned to normal levels in seventh day and continued to decrease down by half of control levels at the end of third week (p=0.005). TAC levels of penile tissue increased twofold in first day (p=0.021) and remained at same high levels for three weeks.

Conclusion: We observed that first day after traumatic urethral injury seems to be very important for evaluation of traumatic injuries and wound healing. We believe when an urethral injury was occured, both urethra and bladder should be handled with care and without delay during urethral healing, because of the presence of oxidative changes in bladder.

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.

Effects of a combination of herbal extracts (modified Ojayeonjonghwan (Wuzi Yanzong wan)) on partial urethral obstruction-induced detrusor overactivity in rats: impact on the nitric oxide pathway and oxidative stress

Background

We investigated the effects of a berry mixture formula (modified Ojayeonjonghwan (Wuzi Yanzong Wan, MO formula) on detrusor overactivity (DO).

Methods

The MO formula consisted of 5 seeds obtained from 5 types of berry plants. Twenty-four Sprague-Dawley rats were randomly assigned to four groups: sham-operated (control), partial urethral obstruction-induced DO (DO group), 0.03 mg/kg solifenacin-treated DO (solifenacin group) and 200 mg/kg MO formula -treated DO (berry mixture). The control and overactive groups were administered distilled water for 4 weeks, and the solifenacin and MO formula groups were treated with the respective medication for 4 weeks. After treatment, cystometrography was performed. At the endo of cystometrography, their bladder tissues were used for identifying the muscarinic receptors, endothelial nitric oxide synthase(eNOS), RhoA, Rock-I & II, 8-hydroxy-2′ –deoxyguanosine(8-OHdG), superoxide dismutase(SOD), interleukin-6 &-8(IL-6, IL-8), and tumor necrosis factor-alpha(TNF-a). The tissues were stained and the muscle-to-collagen ratio was identified.

Results

The presence of the muscarinic receptors were not significantly different between the solifenacin and MO formula groups. However, significant differences were found between the solifenacin and MO formula groups in terms of eNOS, RhoA, Rock-I and -II levels. The muscle-to-collagen ratio was statistically lower in the DO and solifenacin groups; however, no significant difference was observed between the control and MO formula groups. Under oxidative stress, SOD showed a similar result as 8-OHgG. The MO formula group exhibited anti-inflammatory effects, showing that no significant difference was found between the control and MO formula groups regarding values of IL-6, IL-8, and TNF-a. However, the DO and solifenacin groups showed increased IL-6, IL-8, and TNF-a levels. Cystometrography showed that the OAB and solifenacin groups having a significantly lower value than the control and MO formula groups. The mean contraction interval was shorter in the DO, MO formula, and solifenacin groups and the highest in the control group.

Conclusions

The MO formula exhibited a similar pharmacologic effect to that of solifenacin, with anti-inflammatory and antioxidant effects. Enhancement of the MO formula by the nitric oxide pathway affected DO including BPH-related DO. The MO formula may be one of the alternative choices of anticholinergics, a treatment for DO.

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.

Postoperative Urinary Retention is an Independent Predictor of Short-Term and Long-Term Future Bladder Outlet Procedure in Men

PURPOSE

Postoperative urinary retention is a common complication across surgical specialties. To our knowledge no literature to date has examined postoperative urinary retention as a predictor of long-term receipt of surgery for bladder outlet obstruction.

MATERIALS AND METHODS

We retrospectively reviewed the records of inpatients who underwent nonurological surgery in California between 2008 and 2010. Postoperative urinary retention during the index admission was identified, as was receipt of a bladder outlet procedure (transurethral prostate resection, prostate photoselective vaporization or suprapubic prostatectomy) at a subsequent encounter. Patients were matched using propensity scoring of demographics, comorbidities and surgery type. Adjusted Kaplan-Meier analysis was performed to determine the cumulative incidence of subsequent bladder outlet procedures by patient group, including group 1-age 60 years or greater and postoperative urinary retention, group 2-age 60 years or greater and no postoperative urinary retention, group 3-age less than 60 years and postoperative urinary retention, and group 4-age less than 60 years and no postoperative urinary retention.

RESULTS

Of 769,141 eligible male patients postoperative urinary retention developed in 8,051 (1.1%). Following hospital discharge 1,855 patients (0.24%) underwent a bladder outlet procedure. Those treated with a bladder outlet procedure were significantly more likely to have experienced postoperative urinary retention during the index admission (6.3% vs 1.0%, p <0.001). On matched analysis the bladder outlet procedure rate at 3 years was 7.1%, 2.2%, 0.8% and 0.0% in groups 1, 2, 3 and 4, respectively.

CONCLUSIONS

In men 60 years old or older postoperative urinary retention identified those with an increased incidence of bladder outlet procedures within 3 years. Men younger than 60 years had a low rate of subsequent bladder outlet procedures regardless of a postoperative urinary retention diagnosis.

Inhibition of vascular smooth muscle inward-rectifier K+ channels restores myogenic tone in mouse urinary bladder arterioles

Prolonged decreases in urinary bladder blood flow are linked to overactive and underactive bladder pathologies. However, the mechanisms regulating bladder vascular reactivity are largely unknown. To investigate these mechanisms, we examined myogenic and vasoactive properties of mouse bladder feed arterioles (BFAs). Unlike similar-sized arterioles from other vascular beds, BFAs failed to constrict in response to increases in intraluminal pressure (5-80 mmHg). Consistent with this lack of myogenic tone, arteriolar smooth muscle cell membrane potential was hyperpolarized (-72.8 ± 1.4 mV) at 20 mmHg and unaffected by increasing pressure to 80 mmHg (-74.3 ± 2.2 mV). In contrast, BFAs constricted to the thromboxane analog U-46619 (100 nM), the adrenergic agonist phenylephrine (10 µM), and KCl (60 mM). Inhibition of nitric oxide synthase or intermediate- and small-conductance Ca²⁺-activated K⁺ channels did not alter arteriolar diameter, indicating that the dilated state of BFAs is not attributable to overactive endothelium-dependent dilatory influences. Myocytes isolated from BFAs exhibited BaCl₂ (100 µM)-sensitive K⁺ currents consistent with strong inward-rectifier K⁺ (K_IR) channels. Notably, block of these K_IR channels "restored" pressure-induced constriction and membrane depolarization. This suggests that these channels, in part, account for hyperpolarization and associated absence of tone in BFAs. Furthermore, smooth muscle-specific knockout of K_IR2.1 caused significant myogenic tone to develop at physiological pressures. This suggests that 1) the regulation of vascular tone in the bladder is independent of pressure, insofar as pressure-induced depolarizing conductances cannot overcome K_IR2.1-mediated hyperpolarization; and 2) maintenance of bladder blood flow during bladder filling is likely controlled by neurohumoral influences.

Chronic Pelvic Ischemia: Contribution to the Pathogenesis of Lower Urinary Tract Symptoms (LUTS): A New Target for Pharmacological Treatment?

The incidence of lower urinary tract symptoms, including overactive bladder (OAB), is continuing to rise, and is associated with a negative impact on quality of life and a heavy economic burden. A major risk factor for OAB is advancing age. The etiology of OAB is multifactorial and appears to involve myogenic, neurogenic, and urotheliogenic factors. In this article, we review the strengthening preclinical evidence supporting the contribution of chronic pelvic ischemia to the pathogenesis of OAB. In animal models, chronic ischemia induced by arterial injury and a high-fat diet upregulates markers of oxidative stress and proinflammatory cytokines in the urothelium and lamina propria, and leads to increased expression of nerve growth factor. These processes result in increased afferent activity and an increased frequency of micturition, reflecting a state of bladder hyperactivity. In severe, prolonged cases, bladder overactivity may develop into underactivity. Antimuscarinic therapies are the mainstay of OAB treatment, but their usefulness is limited by modest efficacy and troublesome side-effects. Our increasing understanding of the contribution of chronic ischemia to OAB is leading toward novel therapeutic options targeting chronic pelvic ischemia and its morphological, functional, and oxidative consequences. Preclinical trials have demonstrated encouraging results with α1 -adrenoreceptor blockade, phosphodiesterase type 5 inhibition, β3 -adrenoreceptor agonism, free radical scavenging, and stem cell therapy, in preventing morphological, biochemical and functional changes induced by chronic bladder ischemia.