Elucidation of the pathophysiology of interstitial cystitis/bladder pain syndrome via experimental autoimmune cystitis rat model.

Although the cause of interstitial cystitis/painful bladder syndrome (IC/PBS) remains unknown, autoimmune involvement has been strongly suggested to be a contributing factor. To elucidate the pathophysiology of IC/PBS, we characterized the experimental autoimmune cystitis (EAC) in rats. Adult female Sprague-Dawley rats were divided into the EAC and control groups. The EAC rats were generated by administrating a homogenate of donor rat bladder tissue as a bladder antigen. The characteristics of the two groups were determined by evaluating pain behavior and conducting cystometry, histopathology, and molecular analyses. The EAC rats showed: [1] a decreased paw withdrawal threshold, [2] a reduced intercontraction interval on cystometry, [3] the irregular surfaces of the umbrella cells of epithelium throughout the bladder wall, [4] accumulation of stress granules in the bladder and vascular endothelium, [5] the increased expression of genes related to inflammation and ischemia at the mRNA and protein levels, [6] a significantly increased paw withdrawal threshold with pain treatment, and [7] the induction of glomerulation of the bladder wall, epithelium denudation, and lymphocyte infiltration in the interstitium by bladder distension. These results suggest that the EAC rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical IC/BPS, and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury such as bladder distension can cause progression from BPS to IC with Hunner lesions.

Choreito, a Kampo medicine attenuates detrusor overactivity and bladder pain symptoms in rat tranilast-induced interstitial cystitis/bladder pain syndrome-like model.

AIMS: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory condition of the bladder. However, there are only a few medicines that are of pharmaceutical grade and reliably effective for IC/BPS symptoms. Choreito (CRT) is a pharmaceutical-grade Kampo medicine and has been widely prescribed for patients of lower urinary tract symptoms (LUTS) and BPS in Japan. In this study, we exploratory investigated the effects of CRT on the IC/BPS-like symptoms induced by tranilast. METHODS: The rat IC/BPS-like model was induced by feeding administration with 0.4% tranilast. The rats were divided into the three following treatment groups: normal diet (Normal), tranilast treatment (Control), and the groups of 1% CRT (CRT) treatment for IC/BPS-like model. After 4 weeks, continuous cystmetry, locomotor, and vascular permeability was assessed. Furthermore, the cytokine levels in bladder were analyzed by the Bio-Plex suspension array system and plasma monoamine were measured. RESULTS: Control group exhibited 14.3% decrease of locomotor activity in the dark period, and which were 20.3% increase by 1%CRT treatment. The voiding interval was shorter in control than in other groups. 1%CRT suppressed the shortening of voiding interval. Evans blue leakage of bladder wall observed 44.8% higher in control group than in the normal group. The leakage of 1%CRT group was 33.3% less than in the control group. The cytokine level of IFNγ and VEGF were elevated in the control, and CRT treatment suppressed the elevation of IFNγ in the bladder. Plasma noradrenaline was significantly reduced by CRT treatment compared normal group. CONCLUSION: These results suggest that CRT can be an effective therapeutic agent for the treatment of IC/BPS-like symptoms.

Spinal glycinergic and gamma-aminobutyric acid-ergic neurons inhibit the micturition reflex after electrical stimulation of the perineum in rats with pelvic venous congestion.

OBJECTIVES: To examine whether electrical stimulation of the perineum inhibited urinary frequency in rats with pelvic venous congestion, and whether electrical stimulation influences spinal glycinergic/gamma-aminobutyric acid-ergic neurons. METHODS: Bilateral common iliac veins and bilateral uterine veins were ligated to create pelvic venous congestion rats. At 4 weeks after ligation, cystometry was carried out before and after electrical stimulation with/without intrathecal injection of strychnine (a glycine receptor antagonist) and/or bicuculline (a gamma-aminobutyric acid type A receptor antagonist). In addition, measurement of amino acid levels in the lumbosacral cord was carried out with/without electrical stimulation, and cystometry was carried out after oral administration of glycine. RESULTS: Continuous cystometry showed that the interval between bladder contractions was shorter in pelvic venous congestion rats than in sham rats. Electrical stimulation did not change cystometric parameters in sham rats, but the interval between bladder contractions was increased by electrical stimulation in pelvic venous congestion rats. Electrical stimulation increased the levels of glutamic acid, glycine, gamma-aminobutyric acid, and taurine in the lumbosacral cord of pelvic venous congestion rats. Intrathecal strychnine abolished the effects of electrical stimulation in pelvic venous congestion rats, and intrathecal administration of both strychnine and bicuculline shortened the interval between bladder contractions more than before electrical stimulation. Oral administration of glycine (3%) to pelvic venous congestion rats increased bladder capacity. CONCLUSIONS: Electrical stimulation of the perineum inhibits urinary frequency mainly through activation of spinal glycinergic neurons, and partly through activation of gamma-aminobutyric acid-ergic neurons in a rat model of pelvic venous congestion.

Tadalafil improves bladder dysfunction and object recognition in rats with pelvic venous congestion.

OBJECTIVES: To examine the effects of tadalafil on bladder function and object recognition ability in rats with alterations in urinary frequency and locomotor activity as a result of pelvic venous congestion. METHODS: A total of 48 female rats were divided into three groups (sham, pelvic venous congestion and pelvic venous congestion/tadalafil groups). In the pelvic venous congestion and pelvic venous congestion/tadalafil groups, the bilateral common iliac veins and uterine veins were ligated under anesthesia. Rats in the pelvic venous congestion/tadalafil group received a diet containing tadalafil, and the other rats were fed a normal diet. After 4 weeks, rats underwent analysis of voiding behavior, locomotor activity, a novel object recognition test, continuous cystometry, measurement of plasma monoamines, and measurement of plasma and urinary nitric oxide metabolites. Expression of nitric oxide synthase messenger ribonucleic acid in the bladder wall was also assessed, along with histological examination of the bladder. RESULTS: Rats with pelvic venous congestion showed a higher urinary frequency, lower locomotor activity, and lower plasma and urinary nitric oxide levels than sham rats. The bladder wall endothelial nitric oxide synthase messenger ribonucleic acid level was low and object recognition was impaired. Pelvic venous congestion/tadalafil rats showed improvement in locomotor activity, bladder function and object recognition compared with pelvic venous congestion rats, as well as elevation of plasma and urinary nitric oxide, plasma monoamines, and bladder neuronal nitric oxide synthase messenger ribonucleic acid expression. Bladder wall vascularity was greater in pelvic venous congestion/tadalafil rats compared with sham rats. CONCLUSIONS: In rats with pelvic venous congestion, tadalafil might improve bladder function and the general condition by increasing blood flow to the bladder and brain, and by increasing dopamine levels.

Therapeutic effect of propiverine hydrochloride on mixed-type urinary incontinence in women: The Female Urgency and Stress Urinary Incontinence Study of Propiverine Hydrochloride trial.

OBJECTIVES: To show the efficacy of propiverine hydrochloride in the management of symptoms of stress urinary incontinence in female patients with mixed-type urinary incontinence. METHODS: The study was carried out as a multicenter single-arm clinical trial at 64 institutions in Japan. The participants were female patients aged ≥20 years with mixed-type urinary incontinence. The frequency of stress urinary incontinence and urgency urinary incontinence was evaluated at baseline and 4, 8 and 12 weeks after treatment with propiverine hydrochloride. Subjective symptoms were evaluated using the Overactive Bladder Symptom Score and the International Consultation on Incontinence Questionnaire-Short Form. Functional urethral length and maximum urethral closing pressure were also measured at baseline and 12 weeks after treatment at the institutions where the urethral pressure profile was taken. RESULTS: In total, 49 mixed-type urinary incontinence patients were enrolled in the present study. The number of cases of urgency urinary incontinence was reduced time-dependently, which showed statistically significant differences between baseline and 4, 8 and 12 weeks after treatment. A similar statistically different reduction was also observed for stress urinary incontinence. The mean reduction rates of urgency urinary incontinence and stress urinary incontinence at 12 weeks after treatment were 63.9% and 44.3%, respectively. The total scores of International Consultation on Incontinence Questionnaire-Short Form and Overactive Bladder Symptom Score were gradually reduced, and the differences were statistically significant. Functional urethral length and maximum urethral closing pressure at 12 weeks after treatment did not show any statistical differences compared with those at baseline. CONCLUSIONS: Propiverine hydrochloride can be an effective therapeutic option for stress urinary incontinence in patients with mixed-type urinary incontinence.

The role of capsaicin-sensitive C-fiber afferent pathways in the control of micturition in spinal-intact and spinal cord-injured mice.

We examined bladder and urethral sphincter activity in mice with or without spinal cord injury (SCI) after C-fiber afferent desensitization induced by capsaicin pretreatment and changes in electrophysiological properties of mouse bladder afferent neurons 4 wk after SCI. Female C57BL/6N mice were divided into four groups: 1) spinal intact (SI)-control, 2) SI-capsaicin pretreatment (Cap), 3) SCI-control, and 4) SCI-Cap groups. Continuous cystometry and external urethral sphincter (EUS)-electromyogram (EMG) were conducted under an awake condition. In the Cap groups, capsaicin (25, 50, or 100 mg/kg) was injected subcutaneously 4 days before the experiments. In the SI-Cap group, 100 mg/kg capsaicin pretreatment significantly increased bladder capacity and decreased the silent period duration of EUS/EMG compared with the SI-control group. In the SCI-Cap group, 50 and 100 mg/kg capsaicin pretreatment decreased the number of nonvoiding contractions (NVCs) and the duration of reduced EUS activity during voiding, respectively, compared with the SCI-control group. In SCI mice, hexamethonium, a ganglionic blocker, almost completely blocked NVCs, suggesting that they are of neurogenic origin. Patch-clamp recordings in capsaicin-sensitive bladder afferent neurons from SCI mice showed hyperexcitability, which was evidenced by decreased spike thresholds and increased firing rate compared with SI mice. These results indicate that capsaicin-sensitive C-fiber afferent pathways, which become hyperexcitable after SCI, can modulate bladder and urethral sphincter activity in awake SI and SCI mice. Detrusor overactivity as shown by NVCs in SCI mice is significantly but partially dependent on capsaicin-sensitive C-fiber afferents, whereas the EUS relaxation during voiding is enhanced by capsaicin-sensitive C-fiber bladder afferents in SI and SCI mice.

Action of naftopidil on spinal serotonergic neurotransmission for inhibition of the micturition reflex in rats.

AIMS: We examined the mechanism of action of naftopidil, an α1D/A blocker, on spinal descending serotonergic neurotransmission for the micturition reflex. METHODS: We examined (1) urinary 5-hydroxyindole acetic acid (5-HIAA) after intraperitoneal administration of saline, para-chlorophenylalanine (PCPA; a serotonin synthetic enzyme inhibitor), and/or 5-hydroxytryptophan (5-HTP; a serotonin precursor); (2) isovolumetric cystometry after intraperitoneal administration of saline, PCPA, and/or 5-HTP and intravenous injection of naftopidil; and (3) isovolumetric cystometry before and after intrathecal administration of serotonin (5-HT) receptor antagonists and intravenous injection of naftopidil. RESULTS: PCPA decreased and 5-HTP increased urinary 5-HIAA/creatinine. Intraperitoneal injection of PCPA did not influence cystometric parameters. Intraperitoneal injection of 5-HTP significantly shortened the interval between bladder contractions. Intravenous injection of naftopidil transiently abolished bladder contractions. However, the duration of abolishment of bladder contractions after injection of naftopidil in rats given PCPA was significantly shorter than that in rats given vehicle, but significantly longer than that in rats given PCPA and 5-HTP. Intrathecal injection of 5-HT1B, 5-HT3, or 5-HT7 receptor antagonists significantly prolonged the interval between bladder contractions. Intrathecal injection of 5-HT1D or 5-HT2B receptor antagonists significantly shortened the interval between bladder contractions. Combined administration of the maximum non-effective dose of 5-HT1D, 5-HT2A, 5-HT2B, 5-HT2C, or 5-HT3 receptor antagonists and intravenous injection of naftopidil significantly shortened the duration of abolishment of bladder contraction compared to intravenous injection of naftopidil alone. CONCLUSIONS: Naftopidil may inhibit the micturition reflex via 5-HT1D, 5-HT2A, 5-HT2B, 5-HT2C, and 5-HT3 receptors in the spinal cord. Neurourol. Urodynam. 36:604-609, 2017. © 2016 Wiley Periodicals, Inc.

Effects of an alpha1A/D-adrenoceptor antagonist, naftopidil, and a phosphodiesterase type 5 inhibitor, tadalafil, on urinary bladder remodeling in rats with spinal cord injury.

AIMS: In order to clarify whether an alpha1A/D-adrenoceptor (α1 A/D-AR) antagonist, naftopidil, or a phosphodiesterase type 5 (PDE5) inhibitor, tadalafil, prevents bladder wall remodeling after spinal cord injury (SCI), we examined the bladder and urethral activity as well as ischemic and fibrotic changes in the bladder using SCI rats with or without naftopidil or tadalafil treatment. METHODS: Adult female Sprague-Dawley rats were divided into four groups: (1) normal (spinal cord intact); (2) vehicle SCI; (3) naftopidil SCI; and (4) tadalafil SCI groups. In SCI groups, rats underwent Th9-10 spinal cord transection followed by oral application of vehicle, naftopidil (20 mg/kg/day) or tadalafil (2 mg/kg/day) for 1, 2, 4, 8, and 12 weeks. Bladder and urethral pressures, mRNA levels of fibrosis-related molecules and ischemia markers and the composition of bladder collagen and elastin were evaluated. RESULTS: Naftopidil treatment reduced the upregulation of mRNA levels of ischemia and fibrosis markers at the early phase of SCI, and ameliorated the decrease of bladder compliance and voiding efficiency, and the increase of urethral pressure and collagen concentration in the bladder wall at the late phase of SCI. Tadalafil treatment reduced the upregulation of mRNA levels of fibrosis markers, the decrease of bladder compliance and the increase of collagen concentration at the late phase of SCI. CONCLUSIONS: These results suggest that naftopidil and tadalafil treatments improved the bladder remodeling shown by increased bladder collagen contents after SCI in a different time course. Thus, these treatments could be effective for reducing the SCI-related tissue remodeling in the bladder. Neurourol. Urodynam. 9999:XX-XX, 2016. © 2016 Wiley Periodicals, Inc.

Characterization of bladder and external urethral activity in mice with or without spinal cord injury--a comparison study with rats.

To clarify the lower urinary tract function in mice, we compared bladder and urethral activity between rats and mice with or without spinal cord injury (SCI). Female Sprague-Dawley rats and C57BL/6N mice were divided into five groups:1) spinal intact (SI) rats,2) SI mice,3) pudendal nerve transection (PNT) SI mice,4) spinal cord injury (SCI) rats, and 5) SCI mice. Continuous cystometry (CMG) and external urethral sphincter (EUS)-electromyogram (EMG) analyses were conducted under an awake, restrained condition. During voiding bladder contractions, SI animals exhibited EUS bursting with alternating active and silent periods, which, in rats but not mice, coincided with small-amplitude intravesical pressure oscillations in CMG recordings. In SI mice with bursting-like EUS activity, the duration of active periods was significantly shorter by 46% (32 ± 5 ms) compared with SI rats (59 ± 9 ms). In PNT-SI mice, there were no significant differences in any of cystometric parameters compared with SI mice. In SCI rats, fluid elimination from the urethra and the EUS bursting occurred during small-amplitude intravesical pressure oscillations. However, SCI mice did not exhibit clear EUS bursting activity or intravesical pressure oscillations but rather exhibited intermittent voiding with slow large-amplitude reductions in intravesical pressure, which occurred during periods of reduced EUS activity. These results indicate that EUS pumping activity is essential for generating efficient voiding in rats with or without spinal cord injury. However, EUS bursting activity is not required for efficient voiding in SI mice and does not reemerge in SCI mice in which inefficient voiding occurs during periods of reduced tonic EUS activity.

Effects of silodosin on bladder activity in rats with frequent urination induced by pelvic venous congestion.

OBJECTIVE: To examine the effects of silodosin on bladder activity using female rats with frequent urination induced by pelvic venous congestion. METHODS: A total of 24 female rats were divided into three groups: sham, pelvic venous congestion and pelvic venous congestion/silodosin group. Rats in the pelvic venous congestion and pelvic venous congestion/silodosin groups were anesthetized with isoflurane, after which the bilateral common iliac veins and uterine veins were ligated. In the pelvic venous congestion/silodosin group, silodosin (0.3 mg/kg/day) was given using an osmotic pump implanted into the subcutaneous space of the back. After 5-6 weeks, analysis of voiding behavior, measurements of urinary 8-hydroxydeoxyguanosine and nitric oxide metabolites, continuous cystometry under urethane anesthesia, and Evans blue dye extravasation test of the bladder were carried out. RESULTS: In comparison with sham rats, pelvic venous congestion rats showed an increase in urination frequency with a concomitant increase in urine volume, a shorter interval between bladder contractions on continuous cystometry, an increase in urinary 8-hydroxydeoxyguanosine, a decrease in urinary nitric oxide metabolites and an increase in vesical vascular permeability. In comparison with pelvic venous congestion rats, pelvic venous congestion/silodosin rats showed a decrease in urination frequency with a concomitant decrease in urine volume, a lower maximum bladder contraction pressure, a longer interval between bladder contractions, an increase in urinary nitric oxide metabolites and a decrease in vascular permeability. CONCLUSION: Silodosin might improve both bladder dysfunction caused by pelvic venous congestion, and the pelvic venous congestion itself.

Propiverine increases urethral wall catecholamine levels and bladder leak point pressure in rats.

OBJECTIVE: To investigate whether propiverine has a noradrenaline re-uptake inhibitor and whether it acts on the lumbosacral cord or the urethral wall. In addition, we aimed to examine the effect of propiverine on leak point pressure in rats. METHODS: A total of 72 female and 30 male rats were used to examine the following: (i) the change of leak point pressure caused by intravenous agents in rats with vaginal distention; (ii) the change of leak point pressure caused by intrathecal agents in rats with vaginal distention; (iii) the noradrenaline re-uptake inhibitor action of propiverine; and (iv) catecholamine levels in the bladder wall, urethral wall, cerebrospinal fluid and plasma after oral administration of propiverine. RESULTS: Intravenous injection of propiverine, imipramine and duloxetine increased the leak point pressure in rats with vaginal distention. Intrathecal naftopidil decreased the leak point pressure, whereas subsequent intravenous propiverine restored the leak point pressure to the level before intrathecal naftopidil in rats with vaginal distention. Propiverine acted like a noradrenaline re-uptake inhibitor, increasing noradrenaline and/or dopamine levels in the plasma, cerebrospinal fluid, and urethral wall perfusion fluid. CONCLUSION: Propiverine inhibits noradrenaline re-uptake, as well as having antimuscarinic and Ca-antagonist actions. The inhibition of noradrenaline re-uptake by propiverine mainly occurs at the urethral level and partially in the central nervous system, and might stimulate the smooth muscle of the bladder neck and proximal urethra through α1-adrenergic receptors, as well as stimulating the striated muscle of the urethra and pelvic floor by activation of spinal motoneurons. Therefore, propiverine might be effective for both stress and urge incontinence.

Pelvic venous congestion with castration causes chronic prostatitis in rats.

OBJECTIVE: To determine whether castration combined with pelvic congestion could cause chronic prostatitis, and to examine the effect of eviprostat in this rat model. METHODS: Male rats were divided into three groups, which were the sham, castration combined with pelvic congestion and castration combined with pelvic congestion plus eviprostat groups. Rats in the castration combined with pelvic congestion and castration combined with pelvic congestion plus eviprostat groups were anesthetized with isoflurane, after which ligation of the bilateral common iliac veins and castration were carried out. The sham and castration combined with pelvic congestion groups were fed a standard diet, whereas the castration combined with pelvic congestion plus eviprostat group was fed the same diet containing 0.1% eviprostat. After 4 weeks, continuous cystometry was carried out under urethane anesthesia. Then the bladder and the prostate gland were subjected to histological examination. RESULTS: There was no significant difference of the interval between bladder contractions in the sham and castration combined with pelvic congestion plus eviprostat groups, but the interval in the castration combined with pelvic congestion group was significantly shorter than the other groups. There was no difference in the maximum bladder contraction pressure among the three groups. Pathological inflammatory changes of the bladder wall were slightly more severe in the castration combined with pelvic congestion and castration combined with pelvic congestion plus eviprostat groups than in the sham group, whereas bladder vascularity was increased in the castration combined with pelvic congestion plus eviprostat group. In addition, pathological inflammatory changes and glandular atrophy of the prostate were more severe in the castration combined with pelvic congestion and castration combined with pelvic congestion plus eviprostat groups than in the sham group. CONCLUSION: This rat model of pelvic congestion with castration might assist in the development of new treatments for chronic prostatitis and frequency.

Intravenous or local injections of flavoxate in the rostral pontine reticular formation inhibit urinary frequency induced by activation of medial frontal lobe neurons in rats.

PURPOSE: The rostral pontine reticular formation has a strong inhibitory effect on micturition by facilitating lumbosacral glycinergic neurons. We assessed the influence of the rostral pontine reticular formation on the micturition reflex after noradrenaline injection in the medial frontal lobe. We also examined the relation between the medial frontal lobe and the rostral pontine reticular formation. MATERIALS AND METHODS: Continuous cystometry was performed in 28 female rats. After the interval between bladder contractions was shortened by noradrenaline injection in the medial frontal lobe we injected glutamate or flavoxate hydrochloride in the rostral pontine reticular formation or intravenously injected flavoxate or propiverine. The change in bladder activity was examined. RESULTS: Noradrenaline injection in the medial frontal lobe shortened the interval between bladder contractions. In contrast to the bladder contraction interval before and after noradrenaline injection in the medial frontal lobe, the interval was prolonged after noradrenaline injection when glutamate or flavoxate was injected in the rostral pontine reticular formation, or flavoxate was injected intravenously. Noradrenaline injection in the medial frontal lobe plus intravenous propiverine injection also prolonged the interval compared to that after noradrenaline injection alone. However, the interval after noradrenaline injection in the medial frontal lobe plus intravenous injection of propiverine was shorter than that before noradrenaline injection only. CONCLUSIONS: Medial frontal lobe neurons excited by noradrenaline may facilitate the micturition reflex via activation of inhibitory interneurons, which inhibit descending rostral pontine reticular formation neurons that innervate the lumbosacral glycinergic inhibitory neurons. Therefore, the mechanism of micturition reflex facilitation by the activation of medial frontal lobe neurons involves the rostral pontine reticular formation.

Effect of carbazochrome sodium sulfonate on refractory chronic prostatitis.

OBJECTIVES: To study the effect of carbazochrome sodium sulfonate, an agent that reduces capillary permeability, on refractory chronic prostatitis. METHODS: Patients with prostatitis refractory to at least 8 weeks of routine therapy and with urinalysis positive for microhematuria were considered for the present study. In addition to their prior therapy, the patients received carbazochrome at a dose of 30 mg three times a day. The severity of pain (score 0-10), daytime and night-time frequency, international prostate symptom score, global self-assessment, urine occult blood positivity, and adverse events were assessed after 4 and 8 weeks of treatment, and compared with baseline findings. RESULTS: A total of 50 patients (mean age 68.6 ± 8.5 years) were evaluable. The pain score decreased significantly from 3.2 ± 2.1 at baseline to 1.7 ± 1.4 after 4 weeks of treatment and to 1.1 ± 1.8 after 8 weeks. Daytime and night-time frequency, storage symptoms, post-micturition symptoms, and urine occult blood positivity also significantly improved. More than 36% of the patients gave a global self-assessment rating of "improved" or "better" after both 4 and 8 weeks of treatment. Mild adverse events occurred in three patients; one had nausea and two developed drug rash. CONCLUSIONS: Carbazochrome seems to effectively improve pain as well as storage and post-micturition symptoms in patients with refractory chronic prostatitis.

Effect of propiverine hydrochloride on stress urinary incontinence.

OBJECTIVES: To investigate whether the anticholinergic agent, propiverine hydrochloride, is clinically effective for stress urinary incontinence. METHODS: The participants were adult female patients with the chief complaint of stress incontinence. Propiverine (20 mg once daily) was given for 8 weeks. If the response was inadequate after 4 weeks of treatment, the dose was increased to 40 mg/day. Before and after 4 and 8 weeks of treatment, lower urinary tract symptoms were assessed. The urethral pressure and blood catecholamine levels were also measured. RESULTS: A total of 37 patients (mean age 69 ± 11 years) were enrolled, including 15 patients with stress incontinence and 22 with mixed incontinence. The number of episodes of stress incontinence decreased significantly from 2.6 ± 2.3 times per day to 1.3 ± 2.2 times per day after 4 weeks, and 0.4 ± 0.6 times per day after 8 weeks. The daytime and night-time frequency of urination, and quality of life score showed significant improvement. The maximum urethral closing pressure and the functional urethral length increased significantly after treatment, but blood catecholamine levels, blood pressure and pulse rate at 8 weeks were not significantly different from those at baseline. CONCLUSIONS: Propiverine could be an effective drug for stress urinary incontinence by increasing urethral closing pressure without increasing blood catecholamine levels.

[Effect of distigmine at 5 mg daily in patients with detrusor underactivity].

PURPOSE: Since distigmine can cause the serious side effect of cholinergic crisis, its dosage regimen has been reduced to 5 mg/day for patients with difficulty in urination due to detrusor underactivity. Therefore, the efficacy and safety of add-on therapy with distigmine at 5 mg daily were examined in patients with persistent urination problems due to detrusor underactivity despite administration of alpha1-blockers. PATIENTS AND METHODS: The subjects were 39 patients with underactive bladder (18 men and 21 women with an average age of 75 years) who showed no improvement of difficulty in urination or had a residual urine volume > or = 50 ml despite the administration of alpha1-blockers for more than 4 weeks. They received treatment with distigmine (5 mg daily after breakfast) in addition to their alpha1-blockers for 8 weeks. The international prostate symptom score (IPSS), quality-of-life (QOL) score, residual urine volume, blood pressure, and biochemistry tests were investigated before and after addition of distigmine. RESULTS: After four and eight weeks of distigmine administration, all items of the IPSS and QOL score, as well as the residual urine volume, showed a significant decrease. In contrast, the pressure and pulse rate were unchanged. Serum creatinine showed a slight but significant decreased. As adverse events, frequent defecation, fecal incontinence, diarrhea, frequent urination and poor physical condition were recognized in 4 patients, but there was no serious event. CONCLUSION: For difficulty in urination due to detrusor underactivity, the combination of an alpha1-blocker with distigmine at 5 mg daily showed early efficacy and good safety.

Effect of chemical stimulation of the medial frontal lobe on the micturition reflex in rats.

PURPOSE: We assessed the influence of the medial frontal lobe on micturition after chemical stimulation. We also examined the relation between the medial frontal lobe and the rostral pontine reticular formation, which has a strong inhibitory effect on micturition. MATERIALS AND METHODS: A total of 35 female rats underwent continuous cystometry. Bladder activity changes were examined after physiological saline, glutamate, the glutamate receptor antagonist MK-801, noradrenaline or the adrenergic α-1 receptor antagonist naftopidil was injected in the medial frontal lobe. When glutamate was injected in the medial frontal lobe, MK-801 was also injected in the rostral pontine reticular formation. RESULTS: Glutamate injection in the medial frontal lobe prolonged the interval between bladder contractions while injection of the glutamate antagonist MK-801 shortened the interval. Glutamate injection in the medial frontal lobe just after MK-801 injection in the ipsilateral rostral pontine reticular formation also prolonged the interval between bladder contractions. However, after prior injection of MK-801 in the bilateral rostral pontine reticular formation glutamate injection in the medial frontal lobe did not influence cystometric parameters. Noradrenaline injection in the medial frontal lobe shortened the interval between bladder contractions while injection of its antagonist naftopidil prolonged the interval. CONCLUSIONS: Medial frontal lobe neurons excited by glutamate inhibited the micturition reflex via activation of the rostral pontine reticular formation by glutamatergic projection while medial frontal lobe neurons excited by noradrenaline facilitated the micturition reflex. Thus, the medial frontal lobe may be an important integration center for the initiation of micturition and urine storage mechanisms.

Excitatory effect of propiverine hydrochloride on urethral activity in rats.

OBJECTIVES: To investigate the effects of the antimuscarinic agent, propiverine, on the bladder and urethra in rats. METHODS: A total of 54 female rats were given propiverine, imidafenacin (an antimuscarinic agent), or distilled water by gavage once or twice daily. After 2 weeks, bladder and urethral activity were recorded under urethane anesthesia. In the propiverine group, the changes of bladder and urethral activity before and after intravenous injection of α(1) -adrenergic antagonists (prazosin, silodosin and naftopidil) were also recorded. Furthermore, the leak point pressure after electrical stimulation of abdominal wall muscles was measured in rats with vaginal distension from the control and propiverine groups. RESULTS: Intravesical baseline pressure was significantly lower in the propiverine and imidafenacin groups compared with the control group, whereas the urethral baseline pressure was significantly higher in the propiverine group compared with the control or imidafenacin groups. Intravenous injection of prazosin (an α(1) -receptor antagonist) significantly decreased the urethral baseline pressure in both of the propiverine and control groups. Intravenous injection of silodosin and naftopidil (α(1A) - and α(1D) -receptor antagonists, respectively) significantly decreased the maximum contraction pressure and the urethral baseline pressure in the propiverine group. The leak point pressure of the propiverine group was significantly higher than that of the control group. CONCLUSIONS: An increase of catecholamines after propiverine administration might activate smooth muscle of the proximal urethra via α(1A) - and α(1D) -adrenergic receptors, as well as activating urethral and pelvic floor striated muscle via the spinal motoneurons.

Effect of distigmine combined with propiverine on bladder activity in rats with spinal cord injury.

It is not uncommon for patients with spinal cord injury to have both detrusor overactivity during the storage phase and detrusor underactivity during the voiding phase. However, there has been no information about the efficacy of combined treatment with cholinesterase inhibitors and anti-muscarinic agents for this condition. Therefore, the effect of co-administration of distigmine bromide (a cholinesterase inhibitor) and propiverine hydrochloride (an anti-muscarinic agent) on bladder activity was examined in rats with spinal cord injury. Rats were anesthetized with isoflurane and the lower thoracic spinal cord was transected. The bladder was emptied by abdominal compression twice a day for 14 days after surgery. A total of 4 weeks after surgery, the animals were anesthetized with urethane, and the effect of intravenous injection of distigmine (0.01-1 mg/kg) followed by propiverine (1 mg/kg) on continuous cystometry parameters was examined. After injection of distigmine (0.1 and 1 mg/kg), the maximum bladder contraction pressure was significantly increased, and the duration of bladder contraction and the interval between bladder contractions were significantly prolonged. The baseline bladder pressure was not changed by injection of distigmine. After the addition of propiverine, the interval between bladder contractions was significantly further prolonged without any change of the maximum contraction pressure, baseline pressure or duration of bladder contraction. The residual volume after voiding bladder contraction was less than 0.1 mL in all animals. In conclusion, co-administration of distigmine with propiverine might improve both bladder underactivity during the voiding phase and bladder overactivity during the storage phase.

Phenotypic Characterization of the Endocannabinoid-Degrading Enzyme Alpha/Beta-Hydrolase Domain 6 Knockout Rat.

Introduction: Alpha/beta-hydrolase domain 6 (ABHD6) is an enzyme that hydrolyzes 2-arachidonoylglycerol, a high-efficiency endogenous cannabinoid. Although the endocannabinoid system has been suggested to be involved in regulation of bladder function, the roles of ABHD6 in the control of micturition remain unknown. To elucidate the physiological and pathological roles of ABHD6 in vivo, we examined phenotypes of ABHD6 knockout rats (Abhd6-/-) generated by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins system. Materials and Methods: Age-matched knockout and wild-type (WT) rats of both sexes were used. Results: Expression of ABHD6, assessed by quantitative real-time polymerase chain reaction and Western blot analysis, was clearly diminished in Abhd6-/- rats compared with WT rats. Mutant rats had a normal appearance, and the body weight and food consumption were similar to those of WT rats. The interval between bladder contractions assessed by continuous cystometry was significantly shorter in ABHD6 knockout rats than in WT rats when the bladder was stimulated with acetic acid. Mechanical paw withdrawal thresholds measured by von Frey testing were significantly lowered in the knockout rats than in WT rats. The plasma levels of prostaglandin E2 (PGE2) and the stable metabolite of PGE2 in Abhd6-/- rats were twice as high as that in WT rats. Conclusions: Deletion of the ABHD6 gene in rats causes more frequent urination in the stimulated bladder and hyperalgesia to non-noxious mechanical stimuli along with increased plasma PGE2.