Current and Future Pharmacological Treatment for Overactive Bladder:

Resistance Exercise Evokes Changes on Urinary Bladder Function and Morphology in Hypoestrogen Rats

Serum levels of estrogen decrease at climacterium and directly interfere with the urogenital tract. Urinary bladder (UB) is responsive to hormonal changes, especially estrogen. Resistance exercise elicits benefits on severe chronic diseases. Nevertheless, it is still unclear whether the resistance exercise directly affects the UB in ovariectomized (OVx) rats. This study focused on investigating the effects of resistance exercise on UB function and morphology in OVx and control rats. Adult female Wistar rats (∼250-300 g, 14-16 weeks old) [control (n = 20) and OVx (n = 20)] were divided in the following groups: sedentary (SED), and trained over 1 week (acute), 3 weeks (intermediate), and 10 weeks (chronic). Training was carried out in a ladder, with six bouts in alternate days with 75% of body weight load attached to the tail of the animal. Afterward, the animals were isoflurane anesthetized for evaluation of intravesical pressure (IP) changes upon topical administration of acetylcholine (Ach) and noradrenaline (NE) on the UB. At the end of the experiment, the UB was harvested for histological analysis and stained with hematoxylin-eosin and picrosirius red. Ach increased the IP in both OVx and control rats, whereas NE decreased the IP. However, the acute and intermediate groups showed attenuated responses to Ach and NE, while the chronic groups recovered the responses to Ach and NE close to those observed in SED groups. Acute and intermediate groups also showed decreased thickness of the muscular layer, with a reversal of the process with chronic training. In the OVx groups, the acute training reduced the thickness of the smooth muscle and mucosal layers, whereas chronic training increased it. Urothelium thickness decreased in the OVx SED and acute groups. Collagen type I fibers (CI-F) reduced in OVx SED acute and intermediate groups, while collagen type III fibers (CIII-F) increased in the OVx acute group. In the mucosal layer, the volume density of CFs reduced in OVx rats compared to control groups and chronic training resulted in their recovery. Our data suggest that chronic resistance exercise for 10 weeks reversed the functional and morphological changes caused by hypoestrogenism.

Early capsaicin intervention for neurogenic bladder in a rat model of spinal cord injury

We explored capsaicin pretreatment, prior to spinal trauma, as a method to prevent the development of neurogenic detrusor overactivity (NDO) and urethral-bladder dyssynergia reflex after spinal cord injury (SCI). In addition, the duration of effect of capsaicin therapy on NDO in a rat model of SCI was investigated. Two sets of experiments were performed on female Sprague Dawley rats transected at the T9-T10 spinal level. First, SCI rats received capsaicin (125 mg/kg s.q.) 3-4 days before and 4-5 days after SCI. Cystometrograms (CMG) was performed 4 weeks after injury. In the second set of experiments, serial CMG in the same SCI animal was performed after one time injection of capsaicin (125 mg/kg s.q.) 4 weeks after spinalization. There were no differences in intercontraction intervals, voiding efficiency, or voiding pressure between the capsaicin pretreated and control SCI rats. However, the number of uninhibited detrusor contractions decreased 4 weeks after injury. We found that a single dose of capsaicin suppressed uninhibited detrusor contractions for 34 days in the chronic SCI animals. Early therapy with capsaicin was able to prevent/reduce detrusor hyperreflexia in spinal cord injured animals 4 weeks after injury. Early vanilloid therapy may prevent development of urologic sequelae after SCI.

Medical visits among adults with symptoms commonly associated with an overactive bladder

OBJECTIVES

To examine nationally representative data and thus obtain estimates of the use of healthcare providers associated with the overactive bladder (OAB) symptoms, a condition characterized by frequency, urgency and nocturia, with or with no urge incontinence, as although it is ranked among the 10 most common chronic medical conditions in the USA, the level of OAB-associated medical treatment remains largely unknown.

METHODS

To estimate the number of annual OAB-associated medical visits among patients aged > or =18 years, three national databases in the USA (year 2000) were examined: the National Ambulatory Medical Care Survey, the National Hospital Ambulatory Medical Care Survey, and the National Hospital Discharge Survey. Population estimates were constructed using design-based statistical analyses to account for the complex survey designs of data.

RESULTS

During 2000, adult Americans made 1.4 million (95% confidence interval 1.1-1.8 million) ambulatory visits to non-Federal office-based physicians with International Classification of Disease (ICD-9) coding indicative of OAB symptoms. Accounting for emergency and outpatient department visits, as well as non-Federal short-stay hospital discharges, the estimated number of medical visits with OAB-associated ICD-9 coding was <1.5 million.

CONCLUSION

The prevalence of OAB was estimated to be 34 million adult Americans. When 1.4 million ambulatory visits were compared with this prevalence, as few as 4% of adult Americans with OAB sought medical treatment during the year 2000. The present results therefore suggest a large unmet medical need among the population of adult Americans with OAB.

Urinary Incontinence: Proper Assessment and Available Treatment Options

Urinary incontinence is a common condition that imposes significant burdens on the health and well-being of the patient. Urinary incontinence is underreported because people who suffer from the disorder are often reluctant to discuss it with healthcare professionals. It is undertreated because of misperceptions regarding its etiology and amenability to therapy. Failure to distinguish among the different types of urinary incontinence can hinder optimal treatment. This summary paper reviews the types of urinary incontinence, its prevalence, its impact on medical costs and patient quality of life, and approaches to diagnosis and treatment.

Single-blind, randomized controlled study of the clinical and urodynamic effects of an alpha-blocker (naftopidil) and phytotherapy (eviprostat) in the treatment of benign prostatic hyperplasia

AIM

The aim of our study was to examine the efficacy of naftopidil in terms of the international prostate symptom score (IPSS) and urodynamic parameters in the treatment of benign prostatic hyperplasia (BPH). Eviprostat was used as a control to study the efficacy of naftopidil.

METHODS

Forty-nine patients with BPH (mean age 67.9 +/- 7.8 years) were involved in the study. Patients were randomly assigned either to the naftopidil group, which was treated with the alpha-blocker naftopidil (50-75 mg daily, 36 patients), or the eviprostat group, which was treated with phytotherapy (six tablets of eviprostat daily, 13 patients).

RESULTS

The mean total IPSS, the total storage and voiding symptom scores, and the quality of life score decreased significantly (P < 0.0001 for each variable) in the naftopidil group, but not in the eviprostat group. In the naftopidil group, analyses showed significant increases in average and maximum flow rate and bladder capacity at first desire to void (P < 0.001, P = 0.001 and P = 0.024, respectively), and significant decreases in the postvoid residual, the percent of residual and the Abrams-Griffiths number (P = 0.009, P = 0.008 and P = 0.042, respectively). However, in the eviprostat group, no significant changes were noted in terms of these symptomatic and urodynamic parameters. In the pressure/flow study, an improvement in the International Continence Society nomogram grade was noted in 29% of the naftopidil group, but in only 16% of the eviprostat group. Among the 14 patients in the naftopidil group, detrusor overactivity disappeared in 21% and cystometric capacity increased in 36%, but no improvement in detrusor overactivity was noted in the eviprostat group.

CONCLUSIONS

Naftopidil appears to have been effective in this short-term treatment of BPH.

Effects of isolectin B4-conjugated saporin, a targeting cytotoxin, on bladder overactivity induced by bladder irritation

In order to clarify the functional role of the isolectin B4 (IB4)-binding afferent pathway in the micturition reflex, we investigated the effects on bladder activity of intrathecal application of the IB4-saporin conjugate, a targeting cytotoxin that destroys neurons binding IB4. In rats, IB4-saporin (2.5 micro m) or vehicle was administered through an intrathecal catheter implanted at the level of the L6-S1 spinal cord. Three weeks after IB4-saporin administration, cystometry in conscious animals revealed a reduction in bladder overactive responses induced by intravesical capsaicin or ATP infusion without affecting normal voiding function. In histochemical studies, double staining for IB4 and saporin was detected in L6 dorsal root ganglia (DRG) neurons 2 days after the treatment. Three weeks after the treatment, the area in lamina II of the L6 spinal cord stained with IB4 was significantly reduced compared with the area stained in control rats. The staining in the L1 spinal cord was not affected. The percentage of neurons in the L6 DRG intensely labeled with IB4 was also reduced in IB4-saporin-treated rats. These results indicate that intrathecal treatment with the IB4-saporin conjugate at the level of L6-S1 spinal cord, which reduces IB4 afferent nerve terminal staining in lamina II of the L6 spinal cord as well as the number of IB4-binding neurons in L6 DRG, suppressed bladder overactivity induced by bladder irritation without affecting normal micturition. Thus targeting IB4-binding, non-peptidergic afferent pathways sensitive to capsaicin and adenosine 5'-triphosphate may be an effective treatment for overactivity and/or pain responses in the bladder.