Serotonergic modulation of spinal ascending activity and sacral reflex activity evoked by pelvic nerve stimulation in cats

Role of Descending Serotonergic Fibers in the Development of Pathophysiology after Spinal Cord Injury (SCI): Contribution to Chronic Pain, Spasticity, and Autonomic Dysreflexia

As the nervous system develops, nerve fibers from the brain form descending tracts that regulate the execution of motor behavior within the spinal cord, incoming sensory signals, and capacity to change (plasticity). How these fibers affect function depends upon the transmitter released, the receptor system engaged, and the pattern of neural innervation. The current review focuses upon the neurotransmitter serotonin (5-HT) and its capacity to dampen (inhibit) neural excitation. A brief review of key anatomical details, receptor types, and pharmacology is provided. The paper then considers how damage to descending serotonergic fibers contributes to pathophysiology after spinal cord injury (SCI). The loss of serotonergic fibers removes an inhibitory brake that enables plasticity and neural excitation. In this state, noxious stimulation can induce a form of over-excitation that sensitizes pain (nociceptive) circuits, a modification that can contribute to the development of chronic pain. Over time, the loss of serotonergic fibers allows prolonged motor drive (spasticity) to develop and removes a regulatory brake on autonomic function, which enables bouts of unregulated sympathetic activity (autonomic dysreflexia). Recent research has shown that the loss of descending serotonergic activity is accompanied by a shift in how the neurotransmitter GABA affects neural activity, reducing its inhibitory effect. Treatments that target the loss of inhibition could have therapeutic benefit.

The anxiolytic sertraline reduces the impact of psychological stress on bladder function in mice

AIMS

To determine if treatment with the selective serotonin reuptake inhibitor (SSRI) sertraline reduces the bladder dysfunction caused by water avoidance stress in mice.

MAIN METHODS

Adult female mice were randomly allocated to (1) Unstressed, (2) Stressed or (3) Stress + Sertraline experimental groups. Stressed mice were subjected to water avoidance for 1 h/day for 10 days and received sertraline or vehicle in drinking water, starting 10-days prior to the first stress exposure. Age matched control/unstressed mice were house under normal conditions without stress exposure. Voiding behaviour was assessed throughout the experimental protocol. After the final stress exposure, a blood sample was taken to measure plasma corticosterone levels and bladders were removed, catheterised and intravesical pressure responses recorded during distension and in response to pharmacological agents.

KEY FINDINGS

Plasma corticosterone levels in sertraline-treated animals were equivalent to unstressed controls and significantly decreased compared to the stressed group. Voiding frequency was significantly increased in the stressed group, and treatment with sertraline significantly decreased voiding frequency, however, this remained elevated compared to unstressed control animals. Bladders from stressed mice displayed enhanced maximal contractile response to the muscarinic agonist carbachol and greater release of ACh in the serosal fluid, which was reduced to control levels by sertraline treatment. Spontaneous phasic contractions were not altered by stress but were significantly reduced in bladders from sertraline treated animals, relative to controls.

SIGNIFICANCE

These results indicate that management of voiding dysfunction caused by psychological stress may be aided by the addition of an SSRI such as sertraline.

TAS-303, a Novel Selective Norepinephrine Reuptake Inhibitor that Increases Urethral Pressure in Rats, Indicating Its Potential as a Therapeutic Agent for Stress Urinary Incontinence

Stress urinary incontinence (SUI) is characterized by involuntary leakage associated with exertion, effort, sneezing, coughing, or lifting. Duloxetine, a serotonin norepinephrine reuptake inhibitor, is approved for the treatment of patients with SUI in some European countries, but not in the United States. There is currently no globally approved pharmacological drug for the treatment of patients with SUI. Therefore, a new pharmacological treatment option is required. TAS-303 [4-piperidinyl 2,2-diphenyl-2-(propoxy-1,1,2,2,3,3,3-day₇ )acetate hydrochloride] is a novel small-molecule selective norepinephrine reuptake inhibitor that displays significant norepinephrine transporter (NET) inhibitory activity toward the serotonin or dopamine transporters. In this report, we describe the pharmacological properties of TAS-303 and its effects on urethral function, using preclinical in vitro and in vivo studies. Radioligand-binding studies showed that TAS-303 selectively and potently inhibited [³H]norepinephrine binding to the human NET. Oral administration of TAS-303 (3 mg/kg) significantly increased norepinephrine levels in the plasma, whereas it did not significantly affect epinephrine, dopamine, and serotonin levels. TAS-303 (0.3, 1, and 3 mg/kg) dose-dependently increased basal urethral pressure in normal rats and leak point pressure in vaginal distention rats, exhibiting a maximal effect comparable to duloxetine. In the forced swimming test, TAS-303 (100 mg/kg) showed no significant effects on immobility time in rats, raising the possibility that this agent would have minimal central nervous system side effects at an effective dose for urethral function. These results demonstrate that TAS-303 has therapeutic potential for the treatment of patients with SUI.

Urinary incontinence is associated with the development of peptic ulcers in adult women: Data from the KNHANES IV

The aim of this study was to investigate the association between urinary incontinence (UI) and peptic ulcer (PU) and how this is related to psychological stress in Korean women by analyzing the data from the Korea National Health and Nutrition Examination Survey IV (KNHANES).A nationally representative sample of data on 7475 Korean women ≥19 years of age from the KNHANES 2008 to 2010 was included. Physician-diagnosed UI and PU were assessed using questionnaires and surveys. Psychological stress was assessed through a questionnaire using a 4-point Likert scale. Data were analyzed using logistic regression to determine the association between UI and PU according to the level of psychological stress perception.PU was found in 1.41% of the total population. Breaking this down by the existence of UI, PU was found in 3.5% of the population with UI, and 1.4% of the population without UI, which showed a significant difference. A statistically significant trend for increasing prevalence of UI and PU with increasing psychological stress perception levels was found among the study population. Multivariable logistic regression analyses for PU showed that UI was significantly associated with a higher probability of PU in an adjusted model, which means that members of the population with UI were more likely to have PU than those without UI. A higher level of psychological stress perception was also significantly associated with increased odds of PU in the adjusted model.UI could potentiate the development of PU through increasing levels of psychological stress perception.

Dynamic Expression of Serotonin Receptor 5-HT3A in Developing Sensory Innervation of the Lower Urinary Tract

Sensory afferent signaling is required for normal function of the lower urinary tract (LUT). Despite the wide prevalence of bladder dysfunction and pelvic pain syndromes, few effective treatment options are available. Serotonin receptor 5-HT3A is a known mediator of visceral afferent signaling and has been implicated in bladder function. However, basic expression patterns for this gene and others among developing bladder sensory afferents that could be used to inform regenerative efforts aimed at treating deficiencies in pelvic innervation are lacking. To gain greater insight into the molecular characteristics of bladder sensory innervation, we conducted a thorough characterization of Htr3a expression in developing and adult bladder-projecting lumbosacral dorsal root ganglia (DRG) neurons. Using a transgenic Htr3a-EGFP reporter mouse line, we identified 5-HT3A expression at 10 days post coitus (dpc) in neural crest derivatives and in 12 dpc lumbosacral DRG. Using immunohistochemical co-localization we observed Htr3a-EGFP expression in developing lumbosacral DRG that partially coincides with neuropeptides CGRP and Substance P and capsaicin receptor TRPV1. A majority of Htr3a-EGFP+ DRG neurons also express a marker of myelinated Aδ neurons, NF200. There was no co-localization of 5-HT3A with the TRPV4 receptor. We employed retrograde tracing in adult Htr3a-EGFP mice to quantify the contribution of 5-HT3A+ DRG neurons to bladder afferent innervation. We found that 5-HT3A is expressed in a substantial proportion of retrograde traced DRG neurons in both rostral (L1, L2) and caudal (L6, S1) axial levels that supply bladder innervation. Most bladder-projecting Htr3a-EGFP+ neurons that co-express CGRP, Substance P, or TRPV1 are found in L1, L2 DRG, whereas Htr3a-EGFP+, NF200+ bladder-projecting neurons are from the L6, S1 axial levels. Our findings contribute much needed information regarding the development of LUT innervation and highlight the 5-HT3A serotonin receptor as a candidate for future studies of neurally mediated bladder control.

The signaling of amitriptyline-induced inhibitory effect on electrical field stimulation response in colon smooth muscle

Amitriptyline, a well-known antidepressant, exerts inhibitory effect on electrically stimulated rat colon smooth muscle contraction. In this study, we investigated the signaling pathway of amitriptyline-induced inhibitory effect. Changes in isometric force of colon muscle were recorded on polygraph, and data were analyzed by measuring the inhibitory extent induced by amitriptyline. Firstly, muscles were contracted by stimulation with electric field stimulation (EFS), and then, amitriptyline was added cumulatively to determine its influence effect on EFS. Amitriptyline significantly inhibited EFS-induced contraction dose dependently. Then, the mechanism of inhibitory effect of amitriptyline was evaluated by pretreating with various antagonists such as L-NAME, methylene blue, atropine, 5-HT receptors blockers, guanethidine, prazosin, guanabenz, isoprenaline, Y27632 (Rho-kinase inhibitor), ML9 (myosin light chain kinase (MLCK) inhibitor), U73122 (PLC inhibitor), and chelerythrine (PKC inhibitor). Then, Ca(2+) channel blocker (nifedipine) and K(+)channel blockers, tetraethylammonium (TEA), 4-aminopyridine (4-AP), and glybenclamide, were used to determine the involvement of ion channels. L-NAME, guanabenz, 5HT4 receptor blocker, ML9, and Y27632 enhanced the effect of amitriptyline. Meanwhile, methylene blue, atropine, guanethidine, prazosin, methylsergide, ondansetron, U73122, and chelerythrine blocked its effect. It was also shown that nifedipine enhanced but TEA and glybenclamide blocked amitriptyline-induced inhibitory effect on EFS. Our results indicated that amitriptyline may exert inhibitory effect in response to EFS by inhibiting muscarinic receptors and then PLC-mediated PKC pathway leading to opening of ATP-sensitive potassium channel.

Neural control of the lower urinary tract

This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed.

Involvement of 5-HT3 receptors in pudendal inhibition of bladder overactivity in cats

In the present study, the role of 5-HT3 receptors in pudendal neuromodulation of bladder activity and its interaction with opioid receptors were investigated in anesthetized cats. The bladder was distended with either saline to induce normal bladder activity or with 0.25% acetic acid (AA) to induce bladder overactivity. Pudendal afferent nerves were activated by 5-Hz stimulation at multiples of the threshold (T) intensity for the induction of anal twitching. AA irritation significantly reduced bladder capacity to 16.5 ± 3.3% of saline control capacity, whereas pudendal nerve stimulation (PNS) at 1.5-2 and 3-4 T restored the capacity to 82.0 ± 12% (P = 0.0001) and 98.6 ± 15% (P < 0.0001), respectively. Cumulative doses (1-3 mg/kg iv) of ondansetron, a 5-HT3 receptor antagonist, eliminated low-intensity (1.5-2 T) PNS inhibition and reduced high-intensity (3-4 T) PNS inhibition of bladder overactivity. During saline distention, PNS at 1.5-2 and 3-4 T significantly increased bladder capacity to 173.2 ± 26.4% (P = 0.036) and 193.2 ± 22.5% (P = 0.008), respectively, of saline control capacity, but ondansetron (0.003-3 mg/kg iv) did not alter PNS inhibition. Ondansetron (0.1-3 mg/kg) also significantly (P < 0.05) increased control bladder capacity (50-200%) during either AA irritation or saline distention. In both conditions, the effects of low- and high-intensity PNS were not significantly different. After ondansetron (3 mg/kg) treatment, naloxone (1 mg/kg iv) significantly (P < 0.05) decreased control bladder capacity (40-70%) during either AA irritation or saline distention but failed to affect PNS inhibition. This study revealed that activation of 5-HT3 receptors has a role in PNS inhibition of bladder overactivity. It also indicated that 5-HT3 receptor antagonists might be useful for the treatment of overactive bladder symptoms.

Effect of methysergide on pudendal inhibition of micturition reflex in cats

The role of 5-HT2 and opioid receptors in pudendal inhibition of bladder activity induced by intravesical infusion of saline or 0.25% acetic acid (AA) was investigated in anesthetized cats using methysergide (a 5-HT2 receptor antagonist) and naloxone (an opioid receptor antagonist). AA irritated the bladder and significantly (P<0.0001) reduced bladder capacity to 27.0 ± 7.4% of saline control capacity. Pudendal nerve stimulation (PNS) at multiples of the threshold (T) intensity for inducing anal sphincter twitching restored bladder capacity to 60.1 ± 8.0% at 1-2T (P<0.0001) and 92.2 ± 14.1% at 3-4T (P=0.001) of the saline control capacity. Methysergide (0.03-1mg/kg, i.v.) suppressed low intensity (1-2T) PNS inhibition but not high intensity (3-4T) inhibition, and also significantly (P<0.05) increased control bladder capacity at the dosage of 0.3-1mg/kg. During saline infusion without AA irritation, PNS significantly increased bladder capacity to 150.8 ± 9.9% at 1-2T (P<0.01) and 180.4 ± 16.6% at 3-4T (P<0.01) of the saline control capacity. Methysergide (0.1-1 mg/kg) significantly (P<0.05) increased saline control bladder capacity and suppressed PNS inhibition at the dosage of 0.03-1mg/kg. After methysergide treatment (1 mg/kg), naloxone significantly (P<0.05) reduced control bladder capacity during AA infusion but had no effect during saline infusion. Naloxone also had no influence on PNS inhibition. These results suggest that 5-HT2 receptors play a role in PNS inhibition of reflex bladder activity and interact with opioid mechanisms in micturition reflex pathway. Understanding neurotransmitter mechanisms underlying pudendal neuromodulation is important for the development of new treatments for bladder disorders.

Urinary incontinence (UI) and new psychological distress among community dwelling older adults

This study aimed at determining whether UI is associated with increased risk for the onset of psychological distress. This was a population based longitudinal survey of adults aged 50 and older who did not report psychological distress in 1993 and for whom complete data were available. Participants were classified as having UI if they reported uncontrolled urine loss within 12 months of the 1993 interview. Condition-specific functional loss secondary to UI was assessed by questions on participants' ability to engage in certain activities due to UI. Psychological distress was assessed using the General Health Questionnaire (GHQ) in 2004. The continuing participants were living in East Baltimore, Maryland in 1981. Persons with UI in 1993 were more likely to experience new psychological distress in 2004 than were persons without UI in 1993 adjusting for potentially influential covariates (relative odds (RO)=2.18, 95% confidence interval (CI)=1.19-4.01). Persons with condition-specific functional loss secondary to UI were more likely to experience new psychological distress than were persons without UI adjusting for potentially influential covariates (RO=7.57, 95%CI=2.92-19.62). We conclude that UI, especially when associated with condition-specific functional loss, predicted the onset of psychological distress among community dwelling older adults.

Short- and long-term efficacy and safety of duloxetine in women with predominant stress urinary incontinence

OBJECTIVE

To evaluate short- and long-term safety and efficacy of duloxetine in women with predominant stress urinary incontinence (SUI).

RESEARCH DESIGN AND METHODS

The study was a 6-week, double-blind, randomised, parallel, placebo-controlled study followed by an uncontrolled open-label extension (OLE) run in 342 study centres in 16 European countries. Women with predominant SUI were randomly assigned to placebo (n = 1380) or duloxetine 40 mg twice daily (n = 1378) for 6 weeks. Completers of the acute phase were enrolled in the OLE, which had a minimum duration of 6 weeks and ended, based on the approval status of duloxetine in the participating country.

MAIN OUTCOME MEASURES

The primary outcome measure was the change in incontinence episode frequency (IEF) over 6 weeks. Secondary outcome measures were the long-term maintenance of effect on IEF and Patient Global Impression of Improvement (PGI-I), the short- and long-term impact on quality of life using the King's Health Questionnaire (KHQ), and the long-term safety of duloxetine.

RESULTS

After 6 weeks, the decrease in weekly IEF was significantly greater with duloxetine treatment compared to placebo (-50.0 vs. -29.9%; p < 0.001). The percentage of responders (defined as > or =50% decrease in IEF) was significantly higher with duloxetine treatment than with placebo (50.6 vs. 31.2%; p < 0.001). Duloxetine treatment was associated with improvements in weekly pad use (-31.4%), PGI-I ratings (63.6%), and KHQ score (-6.25) compared to placebo (-12.5%, 48.5% and -3.13, respectively, all p < 0.001). Treatment-emergent adverse events were significantly more common during duloxetine treatment (48.3%) than placebo (33.3%), (p < 0.001). Of the 2290 patients continuing into the OLE, 1165 (42.2%) completed the available duration, and 592 (21.5%) discontinued because of an adverse event (percentages relative to total randomised patients). Long-term efficacy in the OLE was assessed over a 72-week period and was maintained over that time. However, the results should be interpreted within the context that better responding patients are more likely to remain on duloxetine, while patients responding poorly are more likely to discontinue over time.

CONCLUSIONS

Duloxetine seems to be an efficacious treatment with an acceptable safety profile for women with SUI. Achieved improvement is maintained over the longer term in those women who remain on therapy.

Major depression and urinary incontinence in women: temporal associations in an epidemiologic sample

OBJECTIVE

To determine whether: (1) major depression is associated with increased risk for onset of urinary incontinence, and (2) urinary incontinence is associated with increased risk for onset of depression.

STUDY DESIGN

Longitudinal cohort study of female Health and Retirement Study participants completing baseline interviews at Wave 3 (1996-1997) and follow-up interviews at Waves 4-6 (1998-2003).

RESULTS

In a cohort of 5820 women with a mean age 59.3 (+/- 0.5) years, 6-year cumulative incidences of depression and incontinence were 11% and 21%, respectively. Major depression was associated with increased odds of incident incontinence (adjusted odds ratio, 1.46; 95% confidence interval, 1.08-1.97) during follow-up compared with those without major depression at baseline. Conversely, incontinence was not associated with increased odds of incident depression (adjusted odds ratio, 1.03; 95% confidence interval, 0.75-1.42) compared with those without incontinence at baseline.

CONCLUSION

Major depression predicted onset of urinary incontinence in a population-based sample of at-risk, community-dwelling women. Incontinence did not predict onset of depression.

Duloxetine versus placebo for the treatment of women with stress predominant urinary incontinence in Taiwan: a double-blind, randomized, placebo-controlled trial

BACKGROUND

This manuscript compares the efficacy and safety of duloxetine with placebo in Taiwanese women with SUI.

METHODS

Taiwanese women with SUI were were randomly assigned to placebo (n = 61) or duloxetine 80 mg/day (n = 60) in this double-blind, 8-week, placebo-controlled study. Outcome variables included: incontinence episode frequency (IEF), Incontinence Quality of Life questionnaire (I-QOL) scores, and Patient Global Impression of Improvement rating (PGI-I).

RESULTS

Decrease in IEF was significantly greater in duloxetine-treated than placebo-treated women (69.98% vs 42.56%, P < .001). No treatment differences in I-QOL scores were significant. There were significant differences in PGI-I rating. Treatment-emergent adverse events (TEAEs) were experienced by more duloxetine-treated than placebo-treated women (80.0% vs 44.3%; P < .001). Discontinuations due to adverse events were significantly greater for duloxetine-treated than placebo-treated women (26.7% vs 6.6%; P = .003).

CONCLUSION

Data provide evidence for the safety and efficacy of duloxetine for the treatment for Taiwanese women with SUI.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00475358.

Urethral closure mechanisms during sneezing-induced stress in anesthetized female cats

During stress-induced increase in abdominal pressure, urinary continence is maintained by urethral closure mechanisms. Active urethral response has been studied in dogs and rats. Such an active urethral response is also believed to occur in humans during stress events. We aimed to investigate urethral closure mechanisms during sneezing in cats. Urethral pressures along the urethra (UP1-UP4), with microtip transducer catheters with UP4 positioned in the distal urethra where the external urethral sphincter (EUS) is located, and intravesical pressure were measured, and abdominal wall, anal sphincter (AS), levator ani (LA), and EUS electromyograms (EMGs) were recorded during sneezing under closed-abdomen and open-abdomen conditions in eight anesthetized adult female cats. Proximal and middle urethral response induced by sneezing was not different from bladder response. Distal urethral response was greater compared with proximal and middle urethral and bladder response. In the open-abdomen bladder, proximal and middle urethral responses were similarly decreased and distal urethral response was unchanged compared with the closed-abdomen bladder. Bladder and urethral responses were positively correlated to sneeze strength. EUS, LA, and AS EMGs increased during sneezing. No urine leakage was observed, regardless of the strength of sneeze. In cats urethral closure mechanisms are partly passive in the proximal and middle urethra and involve an active component in the distal urethra that is believed to result from EUS and possibly LA contractions. Because central serotonin exerts similar effects on the lower urinary tract in cats and humans, the cat may represent a relevant model for pharmacological studies on continence mechanisms.

The role of central 5-hydroxytryptamine (5-HT, serotonin) receptors in the control of micturition

At present the most investigated 5-HT receptor that has been shown to play a role in the control of micturition is the 5-HT(1A) receptor followed by 5-HT(7), 5-HT(2) and 5-HT(3) receptors. Most experiments focus on the control these receptors have on the parasympathetic outflow to the bladder and the somatic outflow to the external urethral sphincter (EUS) in the rat. Furthermore, 5-HT(1A) and 5-HT(7) receptors have been identified as having an excitatory physiological role in the control of bladder function. 5-HT(1A) receptors act, at least in the rat, at both a spinal (probably a heteroreceptor) and supraspinal (probably an autoreceptor) level, while 5-HT(7) receptors only act at a supraspinal level. Additionally, in the rat, 5-HT administered at a spinal or supraspinal site has an excitatory action, although earlier experiments have shown that activating 5-HT-containing brain areas causes inhibition of the bladder. Recent experiments have also indicated that blockade of the 5-HT(1A) receptor pathway shows rapid tolerance. However, no data exist for the development of tolerance for the 5-HT(7) receptor pathway. Neither receptor seems to play a role in the control of the urethra. Regarding 5-HT(2) receptors, activation of this receptor subtype inhibits micturition, and this inhibitory action may occur at a spinal, supraspinal or both levels. Although no physiological role for 5-HT(2C) receptors can yet be identified, 5-HT(2C) receptors have been implicated in the proposed supraspinal tonically active 5-HT(1A) autoreceptor (negative feedback) pathway. This proposition reconciles the data that central 5-HT-containing pathways are inhibitory to micturition, while 5-HT(1A) receptors, although inhibitory to adenylyl cyclase, have an excitatory function. This is because activation of 5-HT(1A) autoreceptors reduces the release of 5-HT thus reducing the activation of the 5-HT(2C) receptors, which are inhibitory in the control of micturition (disinhibition). Furthermore, 5-HT(2A) receptors in the rat and 5-HT(2C) receptors in the guinea pig cause activation of the EUS. In this respect, 5-ht(5A) receptors have also been identified in Onuf's nucleus, the site of somatic motoneurones controlling this sphincter. In the cat there is very little evidence to indicate that 5-HT receptors are involved in micturition except under pathological conditions in which activation of 5-HT(1A) receptors causes inhibition of micturition. Interestingly, under such conditions 5-HT(1A) receptors cause excitation of the EUS. Nevertheless, spinal 5HT(3) receptors have been implicated in the physiological control of micturition in the cat, but not yet in the rat. Overall, the data support the view that 5-HT receptors are important in the control of micturition. However, many more studies are required to fully understand these roles and why there are such species differences.

Urinary hesitancy and retention during treatment with sertraline

We report the cases of two women who began to experience urinary hesitancy and retention after starting treatment with sertraline for depression. Discontinuation of the drug resulted in complete symptom relief. Serotonergic neurons are involved at several levels in control of the lower urinary tract. Retention is apparently an uncommon complication of sertraline. Discontinuation should be considered for patients presenting with voiding difficulties.

Effects of electrical stimulation of the raphe area on the micturition reflex in cats

The raphe nucleus has a variety of physiological functions, including emotion, regulation of skeletal muscle motoneurons, spinal transmission of nociceptive signals, sleep, respiration, gastric motility, and cardiovascular function. Recent evidence has shown that centrally administered serotonin has modulatory effects on micturition function, and that decreased brain serotonin might underlie depression and an overactive bladder. We applied high-frequency stimulation (HFS; 0.2-ms duration, 100 Hz) in the raphe nucleus and the adjacent midline area in 20 supracollicular decerebrate cats, which mostly elicited inhibition of the micturition reflex. The effective amplitude of the electrical stimulation for evoking inhibitory responses was less than 50 muA. We also examined single neuronal activities in the raphe nucleus in response to isovolumetric spontaneous micturition reflexes. In total, 79 neurons were recorded in the raphe nucleus that were related to urinary storage/micturition cycles. Of the neurons recorded, the most common were tonic storage neurons (48%), followed by tonic micturition neurons (28%), phasic storage neurons (18%), and phasic micturition neurons (6%). In addition to the tonic/phasic as well as storage/micturition classification, the neurons showed diverse discharge patterns: augmenting, constant and decrementing, with the constant discharge pattern being most common. Among neurons in the raphe nucleus, the neurons with a decrementing discharge pattern were concentrated in the rostral portion, whereas the augmenting and constant neurons existed diffusely. The storage and micturition neurons were intermingled in the rostral portion, whereas they were separate in the caudal portion. In conclusion, the results of the present study indicate that HFS of the raphe area inhibits the micturition reflex and that there are micturition-related neuronal firings in the raphe area in cats, suggesting that the raphe nucleus is involved in neural control of micturition.

The puzzle of overactive bladder: controversies, inconsistencies, and insights

Overactive bladder (OAB) affects millions of individuals and may severely impair the quality of life of those affected. The contribution of human behavior to manifestations of this symptom complex remains poorly understood. Continued evolution of our understanding of the pathophysiology of OAB has identified contributory mechanisms, which in turn may open new therapeutic avenues. Recent improvements in drug delivery systems represent advances in the management of OAB. However, more complete symptom control with greater tolerability is desirable; this awaits the development of agents specific for newly emerging and as yet unidentified pathophysiologic pathways. Importantly, as understanding of outcomes assessment in OAB matures, refined assessments of disease severity, response to intervention, and patient preference should be possible.

Suppression of bladder reflex activity in chronic spinal cord injured cats by activation of serotonin 5-HT1A receptors

The effects of 8-OH-DPAT (5-HT1A receptor agonist) and WAY100635 (5-HT1A receptor antagonist) on reflex bladder activity were investigated in alpha-chloralose anesthetized or conscious chronic spinal cord injured cats. The results were similar in both anesthetized and conscious animals. Cystometrograms revealed that 8-OH-DPAT (0.5 mg/kg, s.c.) significantly increased the bladder volume threshold for eliciting a large amplitude micturition contraction, but only slightly reduced the amplitude of the contractions and did not alter the small amplitude pre-micturition contractions. 8-OH-DPAT also reduced the amplitude of isovolumetric bladder contractions. The inhibitory effect of 8-OH-DPAT was reversed by WAY100635 (0.5 mg/kg) or blocked by pre-treatment with WAY100635. Reflex bladder contractions evoked by tactile stimulation of the perigenital region were not altered by 8-OH-DPAT. These results suggest that the inhibitory effect of 8-OH-DPAT is mediated by an action on interneuronal pathways in the spinal cord or on the C-fiber afferent limb of the spinal micturition reflex and not on bladder smooth muscle or the efferent limb of the reflex pathway. Drugs that activate 5-HT1A receptors might be useful in treating detrusor overactivity after spinal cord injury.

The role of central 5-HT3 receptors in vagal reflex inputs to neurones in the nucleus tractus solitarius of anaesthetized rats

Brainstem 5-hydroxytryptamine (5-HT, serotonin)-containing neurones modulate cardiovascular reflex responses but the differing roles of the many 5-HT receptors have not been thoroughly investigated. The present experiments on anaesthetized rats investigated the role of 5-HT3 receptors in modulating vagal afferent evoked activity of nucleus tractus solitarius (NTS) neurones. Recordings were made from 301 NTS neurones receiving an input at long (> 20 ms) minimum onset latency from stimulation of the vagus nerve. These included 140 neurones excited by activating non-myelinated cardiopulmonary afferents by right atrial injection of phenylbiguanide (PBG). Ionophoretic application of PBG, a highly selective 5-HT3 receptor agonist, significantly increased activity (from 2.4 +/- 0.4 to 5.5 +/- 0.8 spikes s(-1)) in 96 of 106 neurones tested and in all 17 neurones tested the increase in activity (3.4 +/- 1.1 to 7.0 +/- 1.9 spikes s(-1)) was significantly attenuated (3.0 +/- 0.9 to 3.8 +/- 1.1 spikes s(-1)) by the selective 5-HT3 receptor antagonist granisetron. Ionophoretic application of PBG potentiated responses to vagus nerve and cardiopulmonary afferent stimulation, and granisetron significantly attenuated this cardiopulmonary input (20.2 +/- 5.7 to 10.6 +/- 4.1 spikes burst(-1)) in 9 of 10 neurones tested. Ionophoretic application of AMPA and NMDA also excited NTS neurones and these excitations could be selectively antagonized by the non-NMDA and NMDA receptor antagonists DNQX and AP-5, respectively. At these selective currents, DNQX and AP-5 also attenuated PBG- and cardiopulmonary input-evoked increases in NTS activity. These data are consistent with the hypothesis that vagal inputs, including non-myelinated cardiopulmonary inputs to the NTS, utilize a 5-HT-containing pathway which activates 5-HT3 receptors. This excitatory response to 5-HT3 receptor activation may be partly a direct postsynaptic action but part may also be due to facilitation of the release of glutamate which in turn acts on either non-NMDA or NMDA receptors to evoke excitation.

Prevalence of urinary incontinence in relation to self-reported depression, intake of serotonergic antidepressants, and hormone therapy in middle-aged women: a report from the Women's Health in the Lund Area study

OBJECTIVE

To study a perceived relationship of urinary incontinence with self-reported depression among middle-aged women, and to outline whether hormone therapy, selective serotonin reuptake inhibitors, or serotonin norepinephrine reuptake inhibitors influence the prevalence of urinary incontinence.

DESIGN

A population-based cross-sectional study of 6,642 women from the Lund area, Sweden, aged 50 to 64 years, who answered questions on urinary incontinence. We obtained information on urinary incontinence, self-reported depression, and medication by questionnaire and personal interviews between December 1995 and February 2000.

RESULTS

Thirty-one percent of the women reported urinary incontinence of various severities and 52% reported episodes of depression. Urinary incontinence and self-reported depression were significantly associated [odds ratio (OR) 1.37; 95% CI, 1.23-1.52; P < 0.001]. Among women with self-reported depression, the use of serotonergic antidepressants was statistically associated with urinary incontinence (OR 1.78; 95% CI, 1.33-2.38; P < 0.001). Among women not reporting depression, hormone therapy was significantly associated with urinary incontinence (OR 1.45; 95% CI, 1.22-1.70; P < 0.001). After adjustment for other potential risk factors, serotonergic antidepressants and hormone therapy use were no longer associated with urinary incontinence in women with self-reported depression. However, among women not reporting depression, hormone therapy was still significantly more common in women with urinary incontinence.

CONCLUSIONS

Urinary incontinence and self-reported depression seemed to be associated in middle-aged women. Use of serotonergic antidepressants or hormone therapy does not seem to be associated with a lower prevalence of urinary incontinence.

Pharmacotherapy for stress urinary incontinence : present and future options

Stress urinary incontinence (SUI) is the accidental leakage of urine associated with physical activities such as running, jumping or lifting, or with sneezing and coughing. Worldwide, SUI is a highly prevalent condition, both in young and elderly women, and is a condition fraught with social isolation, loss of self-esteem and significant financial burden. Most women with SUI assume that it is an inevitable part of aging and "suffer in silence", relying on absorbent pads or lifestyle changes to cope with their condition.Unfortunately, for those who do seek medical treatment, the absence of effective and well tolerated pharmacological treatments for SUI limits the clinician's choices to behavioural modification, biofeedback and surgery. Many of the nonsurgical approaches have low success rates, particularly in the elderly and more severely afflicted. Although most continence surgeries have been reported to produce very high cure rates, many women are willing to live with their condition rather than undergo such invasive options. In an attempt to help these patients, some physicians prescribe off-label agents, including tricyclic antidepressants such as imipramine, alpha- and beta-adrenoceptor agonists, and estrogen replacement therapy. The use of these therapies has been limited by unpredictable results and adverse reactions. In addition, acetylcholine receptor antagonists are often prescribed for SUI, despite the fact that these medications have never been shown to be effective in this condition. This lack of a reliable pharmaceutical agent led to the development of duloxetine, a balanced dual reuptake inhibitor of serotonin and norepinephrine that is also being studied for the treatment of major depressive disorder. Based on in vivo data in animals, duloxetine is believed to increase the strength of urethral sphincter contractions and, thereby, prevent accidental urine leakage by increasing urethral closure forces. In clinical trials in women with SUI, duloxetine has demonstrated efficacy in reducing incontinence episodes and increasing the quality of life with no serious adverse effects. Nausea was the most common adverse event; however, in most patients it was reported early in treatment, mild-to-moderate in severity and transient. A medication such as duloxetine, if approved, would go a long way towards expanding the available treatment options for patients with SUI.

Acupuncture for chronic prostatitis/ chronic pelvic pain syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is prevalent in urological practice and has a significant impact on quality of life. Standard therapies often fail to achieve sustainable amelioration of symptoms. This article attempts to show that neuromodulatory treatment in the form of electroacupuncture can be a minimally invasive and effective treatment for CP/CPPS that is refractory to standard therapies. This neuromodulatory therapy lends support to the hypothesis that the end stage of CP/CPPS may be a neuropathic pain syndrome.

Duloxetine vs placebo in the treatment of stress urinary incontinence: a four-continent randomized clinical trial

OBJECTIVES

To further assess, in a phase 3 study, treatment with duloxetine for women with stress urinary incontinence (SUI) in other geographical regions, including Argentina, Australia, Brazil, Finland, Poland, South Africa and Spain, as previous trials in North America and Europe provided evidence for the safety and efficacy of duloxetine as a pharmacological treatment for SUI in women.

PATIENTS AND METHODS

The study included 458 women aged 27-79 years enrolled in a double-blind, placebo-controlled trial. The patients with predominantly SUI were identified using a validated clinical algorithm. They were randomly assigned to receive placebo (231) or duloxetine 40 mg twice daily (227) for 12 weeks. The primary outcome variables included the incontinence episode frequency (IEF) and the Incontinence Quality of Life (I-QOL) questionnaire. Van Elteren's test was used to analyse the percentage changes in IEF where the stratification variable was weekly baseline IEF (IEF < 14 and > or = 14). Analysis of covariance was used to analyse I-QOL scores.

RESULTS

The mean baseline IEF was 18.4/week; 55% of patients had a baseline IEF of > or = 14. There was a significantly greater median decrease in IEF with duloxetine with placebo (54% vs 40%, P = 0.05), with comparable significant improvements in quality of life (I-QOL score increases of 10.3 vs 6.4, P = 0.007). The improvements with duloxetine were associated with significantly greater increases in voiding intervals than with placebo (20.4 vs 8.5 min, P < 0.001). The placebo response was 10.7% and 12.5% higher than those reported in two European and North American phase 3 trials. This may have been related to more patients being naïve for incontinence management in the current trial. Discontinuation rates for adverse events were 1.7% for placebo and 17.2% for duloxetine (P < 0.001), with nausea being the most common reason for discontinuation (3.1%); it was the most common adverse event with duloxetine, but was mild or moderate in most (81%), did not worsen in any patient and resolved within 7 days in 60% and within 1 month in 86% of continuing patients; 88% of women who experienced nausea while taking duloxetine completed the trial.

CONCLUSIONS

These results show improvements in incontinence and quality of life with duloxetine 40 mg twice daily for 12 weeks that are in keeping with those reported in two other recently completed phase 3 trials in Europe and North America.

Mixed incontinence

The epidemiology and treatment of mixed incontinence has received relatively little attention. However, mixed incontinence--defined as the combination of stress and urge incontinence--accounts for approximately 33% of all cases of incontinence in women. The condition often responds poorly to treatment, either pharmacologic or surgical. Potential pharmacologic approaches for mixed incontinence include antimuscarinic agents, estrogen replacement therapy (for postmenopausal women), and dopamine, serotonin, or norepinephrine reuptake inhibitors. In a large-scale, multinational, placebo-controlled, clinical trial, the antimuscarinic agent tolterodine significantly reduced incontinence episodes in women with mixed symptoms. The benefits of tolterodine continued to increase during the 8 weeks of the trial and extended to additional end points, including frequency, urgency, and urge incontinence. A limited number of studies have examined the use of estrogen for mixed incontinence and have produced conflicting results. Duloxetine oxalate, a combined serotonin/norepinephrine reuptake inhibitor, has shown great promise in animal studies, as well as in phase 2 and 3 clinical trials. This agent is the first to demonstrate efficacy as a sole therapy for stress incontinence and has exhibited favorable effects on bladder capacity, suggesting possible benefits in mixed incontinence. Only 5 studies (2 of which were conducted during the 1980s) have specifically examined the use of surgery for the treatment of mixed incontinence; the cure rates reported have varied. The current body of information supports use of an antimuscarinic agent as initial therapy for mixed incontinence, although long-term trials are needed to shed more light on the duration of benefit.

Duloxetine versus placebo in the treatment of European and Canadian women with stress urinary incontinence

OBJECTIVE

To assess the efficacy and safety of duloxetine in women with stress urinary incontinence.

DESIGN

Randomised double-blind, placebo-controlled clinical trial.

SETTING

Fort-six centres in seven European countries and Canada.

POPULATION

Four hundred and ninety-four women aged 24-83 years identified as having predominant symptoms of stress urinary incontinence using a clinical algorithm that was 100% predictive of urodynamic stress urinary incontinence in a subgroup of 34 women.

METHODS

The case definition included a predominant symptom of stress urinary incontinence with a weekly incontinence episode frequency > or =7, the absence of predominant symptoms of urge incontinence, normal diurnal and nocturnal frequencies, a bladder capacity > or =400 mL and both a positive cough stress test and positive stress pad test. Subjects completed two urinary diaries prior to randomisation and three diaries during the active treatment phase of the study, each completed during the week prior to monthly visits. Subjects also completed quality of life questionnaires at each visit. Safety was assessed by the evaluation of treatment-emergent adverse events, discontinuation of treatment because of adverse events, serious adverse events, vital sign measurements, electrocardiograms (ECG) and clinical laboratory tests.

INTERVENTION

After a two-week placebo lead-in, women received placebo or duloxetine 40 mg BD for 12 weeks.

MAIN OUTCOME MEASURES

The percentage decrease in incontinence episode frequency and the change in the Incontinence Quality of Life (I-QOL) questionnaire total score were prespecified as co-primary outcome variables in the protocol.

RESULTS

Incontinence episode frequency decreased significantly with duloxetine compared with placebo (median decrease of 50%vs 29%; P= 0.002) with comparable improvements in the more severely incontinent subgroup (those experiencing at least 14 incontinence episodes per week at baseline; 56%vs 27% decreases; P < 0.001). The primary analysis of I-QOL scores did not reveal a significant difference between treatment groups, due primarily to the carrying forward of low scores from patients who discontinued treatment very early due to duloxetine-associated adverse events. The increase in I-QOL scores was significantly greater for duloxetine than for placebo at each of the three postrandomisation visits after 4, 8, and 12 weeks of treatment. Discontinuation rates for adverse events were higher for duloxetine (22%vs 5%; P < 0.001) with nausea being the most common reason for discontinuation (5.3%). Nausea tended to be mild to moderate, not progressive, and transient.

CONCLUSIONS

The findings support duloxetine as a potential treatment for women with stress urinary incontinence.

Serotonergic modulation of bladder afferent pathways

Normal bladder function is based on activation and maintenance of a sophisticated reflex mechanism involving sympathetic, parasympathetic, and somatic control of the lower urinary tract. The spinal and supraspinal neuronal pathways involved can be modulated by activation or inhibition of neurons in the periphery, at the lumbosacral and thoracolumbar spinal levels, and at supraspinal regulatory sites. Activation of the primary afferent neurons that innervate the lower urinary tract is the first step on this reflex pathway. Under conditions in which bladder function is compromised, abnormal activity in these afferent neurons can induce changes in these circuits, resulting in bladder dysfunction. Control and modulation of afferent pathways is a recent focus for the development of novel treatments for lower urinary tract disorders. This review focuses on the central regulation of bladder function by central serotonergic modulation of sensory pathways. Modulation of this monoaminergic system has dramatic effects on bladder activity and can be a target for pharmacologic treatment of bladder disorders.

Duloxetine versus placebo for the treatment of North American women with stress urinary incontinence

PURPOSE

Duloxetine, a selective serotonin and norepinephrine reuptake inhibitor, increases rhabdosphincter contractility via the stimulation of pudendal motor neuron alpha-1 adrenergic and 5-hydroxytryptamine-2 receptors. In this first phase 3 study we assessed the efficacy and safety of duloxetine in women with stress urinary incontinence (SUI).

MATERIALS AND METHODS

A total of 683 North American women 22 to 84 years old were enrolled in this double-blind, placebo controlled study. The case definition included a predominant symptom of SUI with a weekly incontinence episode frequency (IEF) of 7 or greater, the absence of predominant symptoms of urge incontinence, normal diurnal and nocturnal frequency, a bladder capacity of 400 ml or greater, and a positive cough stress test and stress pad test. After a 2-week placebo lead-in period subjects were randomly assigned to receive placebo (339) or 80 mg duloxetine daily (344) as 40 mg twice daily for 12 weeks. Primary outcome variables included IEF and an incontinence quality of life questionnaire. Van Elteren's test was used to analyze percent changes in IEF with a stratification variable of weekly baseline IEF (less than 14 and 14 or greater). ANCOVA was used to analyze incontinence quality of life scores.

RESULTS

Mean baseline IEF was 18 weekly and 436 subjects (64%) had a baseline IEF of 14 or greater. There was a significant decrease in IEF with duloxetine compared with placebo (50% vs 27%, p <0.001) with comparably significant improvements in quality of life (11.0 vs 6.8, p <0.001). Of subjects on duloxetine 51% had a 50% to 100% decrease in IEF compared with 34% of those on placebo (p <0.001). These improvements with duloxetine were associated with a significant increases in the voiding interval compared with placebo (20 vs 2 minutes, p <0.001) and they were observed across the spectrum of incontinence severity. The discontinuation rate for adverse events was 4% for placebo and 24% for duloxetine (p <0.001) with nausea the most common reason for discontinuation (6.4%). Nausea, which was also the most common side effect, tended to be mild to moderate and transient, usually resolving after 1 week to 1 month. Of the 78 women who experienced treatment emergent nausea while taking duloxetine 58 (74%) completed the trial.

CONCLUSIONS

These phase 3 data are consistent with phase 2 data and they provide further evidence for the safety and efficacy of duloxetine as a pharmacological agent for the treatment of women with SUI.

Duloxetine: a serotonin-noradrenaline re-uptake inhibitor for the treatment of stress urinary incontinence

Stress urinary incontinence (SUI) is the accidental leakage of urine associated with physical activities such as running, jumping or lifting or with sneezing and coughing. For many patients it can be a very bothersome symptom, causing social isolation, loss of self-esteem and increased financial outlays. Although there is currently no medication approved worldwide for the treatment of SUI, a variety of off-label agents are sometimes prescribed. Duloxetine (LY-248686; Eli Lilly), a new centrally acting compound with dual activity as a serotonin and noradrenaline re-uptake inhibitor, offers a promising new approach for treatment. Due to its inhibition of presynaptic neuron re-uptake of serotonin and noradrenaline in the sacral spinal cord, duloxetine is believed to increase the strength of urethral sphincter contractions and thereby prevent accidental urine leakage by increasing urethral closure pressure. In three published trials in women with the predominant symptom of SUI, duloxetine significantly reduced the number of incontinence episodes compared to placebo. Adverse events were usually observed early in treatment, were mild-to-moderate in severity and were transient. Nausea was the most common reason for discontinuation.

Evidence for the involvement of central 5-HT7 receptors in the micturition reflex in anaesthetized female rats

(1) The effects of the selective 5-HT7 receptor antagonists SB-269970 (3-300 microg kg-1; n=5-6) and SB-656104 (30 microg kg-1; n=5) administered centrally (i.c.v.) were investigated on the 'micturition reflex' in the urethane anaesthetized female rat. (2) In cystometric recordings, SB-269970 caused significant increases in volume of 58+/-15 and 138+/-33% and pressure of 140+/-46 and 149+/-60% thresholds at 10 and 30 microg kg-1. These changes were associated with significant decreases in distension-induced bladder contraction of 62+/-14 and 60+/-11%, respectively. However, there was no change in residual volume. At the higher doses, SB-269970 blocked the micturition reflex. SB-656104 had similar effects to SB-269970 but in addition significantly increased the residual volume. (3) SB-269970 (10 microg kg-1; n=5) given i.v. had no effect on the micturition reflex. (4) SB-269970 (30 microg kg-1; n=4) given intrathecally (i.t.) had no effect on micturition reflex, although the selective 5-HT1A receptor antagonist WAY-100635 given i.t. after SB-269970 caused a significant increase in the volume threshold. (5) Using an isovolumetric method in which urethral changes were measured, SB-269970 (30 microg kg-1; n=4; i.c.v.) failed to have any effect on these urethral-evoked changes although they significantly reduced the amplitude of the bladder contraction. (6) These data demonstrate that 5-HT7 receptors located supraspinally in the rat are involved in the control of micturition.

Suppression of the micturition reflex in urethane-anesthetized rats by intracerebroventricular injection of WAY100635, a 5-HT(1A) receptor antagonist

The influence of supraspinal 5-HT(1A) receptors on reflex bladder activity was evaluated in anesthetized rats by studying the effects of intracerebroventricular (i.c.v.) administration of WAY100635 (1-100 microg), a selective 5-HT(1A) receptor antagonist. The drug dose-dependently decreased the frequency and/or amplitude of isovolumetric reflex bladder contractions. Low doses (1-10 microg) increased the interval between contractions but only slightly reduced the amplitude of the contractions. However, 100 microg of WAY100635 elicited an initial complete block of bladder reflexes followed by a recovery period lasting 10-15 min during which the frequency of reflex contractions was normal but the amplitude was markedly suppressed by 70-80%. Mesulergine (0.1 mg/kg, i.v.), a 5-HT(2C) antagonist, which transiently eliminated bladder activity in some rats (five of 11), blocked the inhibitory effect of WAY100635 (10 or 100 microg, i.c.v.) in only two of six rats. Our data coupled with the results of previous studies suggest that spinal and supraspinal 5-HT(1A) receptors are involved in multiple inhibitory mechanisms controlling the spinobulbospinal micturition reflex pathway. The regulation of the frequency of bladder reflexes is presumably mediated by a suppression of afferent input to the micturition switching circuitry in the pons, whereas the regulation of bladder contraction amplitude may be related to an inhibition of the output from the pons to the parasympathetic nucleus in the spinal cord.

Age-associated changes in the monoaminergic innervation of rat lumbosacral spinal cord

The effects of ageing on the innervation patterns of lumbosacral spinal nuclei involved in controlling lower urinary tract functions, including micturition, were studied using immunohistochemistry for serotonin (5-HT) and tyrosine hydroxylase (TH) in male Wistar rats of 3 and 24 months. Quantitative image analysis revealed significant age-associated declines in the innervation of most regions including the intermediolateral cell nucleus, sacral parasympathetic nucleus, dorsal grey commissure and in the ventral horn including the dorsolateral nucleus which in the rat is one of the component nuclei homologous to Onuf's nucleus in man. Notable exceptions to this generalised decline were observed in the 5-HT innervation of the sacral parasympathetic nucleus, which was maintained, and in the region of the dorsolateral motor nucleus where TH-like immunoreactivity did not significantly decline. These results suggest that the changes in micturition characteristics observed in aged rats may in part be a consequence of the alterations in, and decline of, aminergic inputs to both autonomic and somatic spinal nuclei associated with bladder function.

Neurological disorders cerebrovascular disease and parkinsonism

To store and expel urine at appropriate intervals, the lower urinary tract requires extensive input and control from the peripheral autonomic, somatic, and central nervous systems. Neurological disorders, such as cerebrovascular disease and Parkinson's disease, often cause functional disturbances of the lower urinary tract.

Spinal cord neural organization controlling the urinary bladder and striated sphincter

The storage and elimination of urine requires the coordination of activity between the autonomic nervous system (thoracolumbar sympathetic and sacral parasympathetic divisions) controlling the urinary bladder and urethra and the lumbosacral somatic motoneurons innervating the striated sphincter and pelvic floor muscles. These three efferent systems involved in the control of lower urinary tract function receive segmental sensory information from various visceral organs and the perineum, as well as inputs from supraspinal regions. Ascending and descending connections between the various spinal segments levels and supraspinal regions provide the reflex substrates participating in normal bladder continence and micturition reflexes. Many of the actions of descending and segmental reflexes are mediated by excitatory and inhibitory sacral spinal interneurons located within the region of the parasympathetic preganglionic autonomic neurons and the sphincter ventral horn motoneurons. This review will: (1) discuss the basic organization and spinal elements of the reflex pathways subserving continence and micturition; (2) describe features of the identified sacral interneuronal circuitry contributing to the control of the bladder and sphincter function; and (3) discuss how changes in the control of these reflex pathways and neurons may contribute to abnormal patterns of bladder and sphincter function commonly observed following spinal cord injury.

Pharmacologic management of urinary incontinence in women

This article summarizes current thought regarding the efficacy of various types of drug therapy for incontinence in women, borrowing liberally from similar previous presentations. Space limitations for this chapter necessitate some simplification and condensation of these subjects. References have generally been chosen because of their informational or review content and not because of originality or initial publication on a particular subject.

Role of supraspinal serotonin receptors for micturition in normal conscious rats

Serotonin (5-HT) receptors are widely distributed in the central nervous system, including several areas involved in the control of micturition reflex pathways. However, the roles of the different subtypes of 5-HT receptors are not well known. We studied in normal, conscious rats, the effects on the cystometrogram of intracerebroventricular (i.c.v.) administration of 5-HT, 8-hydroxy-2-(di-N-propylaminotetralin) (8-OH-DPAT; agonist at 5-HT(1A) receptors), alpha-methyl-5-hydroxytryptamine maleate (agonist at 5-HT(2) receptors), 2-methyl-5-hydroxytryptamine hydrochloride (agonist at 5-HT(3) receptors), and 1-(4-amino-5-chloro-2methoxyphenyl)-3-(1-n-butyl-4piperidinyl)-1-propanone hydrochloride (RS67506; agonist at 5-HT(4) receptors). Female Sprague-Dawley rats, weighing approximately 230 g, were used. A polyethylene catheter was inserted into the bladder through the dome for cystometric investigations. For administration of drugs, a catheter was implanted into the right cerebral ventricle. Three days after implantation of the bladder catheter, continuous cystometry was performed. Administration of 5-HT (6 nmol/kg i.c.v.), 8-OH-DPAT (6 nmol/kg), alpha-methyl-5-hydroxytryptamine maleate (6 nmol/kg), or RS67506 hydrochloride (6 nmol/kg) significantly (P < 0.05) increased micturition pressure and decreased bladder capacity and micturition volume. The effects increased in a dose-dependent manner (18, 60 nmol/kg). Intracerebroventricular administration of 2-methyl-5-hydroxytryptamine hydrochloride (60 nmol/kg) caused no change in the cystometric parameters. The results suggest that in normal conscious rats, at the supraspinal level, 5-HT (via 5-HT(1A), 5-HT(2), and 5-HT(4) receptors) can enhance the micturition reflex induced by bladder filling. Whether this means that 5-HT(1A), 5-HT(2), and 5-HT(4) receptors can be targets for drugs meant for treatment of bladder hyperactivity, should be explored.

Duloxetine versus placebo in the treatment of stress urinary incontinence

OBJECTIVE

The purpose of this study was to assess the efficacy and safety of duloxetine, a selective inhibitor of serotonin and norepinephrine reuptake, in the treatment of stress urinary incontinence.

STUDY DESIGN

A double-blind, randomized, placebo-controlled study was conducted in 553 women aged 18 to 65 years with a predominant symptom of stress urinary incontinence. Subjects were randomized to placebo (n = 138 women) or duloxetine at one of three doses (20 mg/d, n = 138 women; 40 mg/d, n = 137 women; or 80 mg/d, n = 140 women). Outcome variables that were assessed after 12 weeks of treatment included incontinence episode frequency recorded in a real-time diary and answers provided to the Patient Global Impression of Improvement scale and the Incontinence Quality of Life questionnaire.

RESULTS

Duloxetine was associated with significant and dose-dependent decreases in incontinence episode frequency that paralleled improvements that were observed in the Patient Global Impression of Improvement scale and the Incontinence Quality of Life questionnaire. The median incontinence episode frequency decrease with the use of the pooled diary analysis with placebo was 41% compared with 54% for duloxetine 20 mg per day (P =.06), 59% for duloxetine 40 mg per day (P =.002), and 64% for duloxetine 80 mg per day (P <.001). One half of the subjects at the 80 mg per day dose had a > or = 64% reduction in incontinence episode frequency (P <.001 vs placebo); 67% had > or = 50% reduction (P =.001 vs placebo). These improvements were observed despite significant concurrent dose-dependent increases in the average voiding interval in the duloxetine groups compared with the placebo group. Similar statistically significant improvements were demonstrated in a subgroup of 163 subjects who had more severe stress urinary incontinence (> or = 14 incontinence episode frequency per week; 49%-64% reduction in incontinence episode frequency in the duloxetine groups compared with 30% in the placebo group). Discontinuation rates for adverse events were 5% for placebo and 9%, 12%, and 15% for duloxetine 20, 40, and 80 mg per day, respectively (P =.04). Nausea was the most common symptom that led to discontinuation. None of the adverse events that were reported were considered to be clinically severe.

CONCLUSION

This trial provides evidence for the efficacy and safety of duloxetine as a pharmacologic agent for the treatment of stress urinary incontinence.

Influence of central serotonergic mechanisms on lower urinary tract function

The effects of serotonergic drugs on the central nervous system control of the lower urinary tract have revealed possible approaches for the treatment of detrusor overactivity and urinary incontinence. Studies in animals of the distribution of serotonergic nerves and receptors and the changes in voiding function induced by serotonin (5-hydroxytryptamine [5-HT]) receptor agonists and antagonists, as well as 5-HT reuptake inhibitors, form a basis for the development of such treatments. In rats and cats, spinal reflex circuits involved in voiding function exhibit a dense serotonergic innervation, multiple 5-HT receptors, and sensitivity to various drugs that affect serotonergic transmission. Although there is some evidence in the rat for serotonergic facilitation of voiding, most experiments in rats and cats indicate that activation of the central serotonergic system by 5-HT reuptake inhibitors, as well as by 5-HT1A and 5-HT2 receptor agonists, depresses reflex bladder contractions and increases the bladder volume threshold for inducing micturition. These data indicate that activation of the central serotonergic system can suppress voiding by enhancing efferent control of the urethral outlet and inhibiting the parasympathetic excitatory input to the urinary bladder. The 5-HT receptors and reuptake mechanisms, therefore, represent targets for the development of new treatments of detrusor overactivity and urinary incontinence.

Effects of two atypical neuroleptics, olanzapine and risperidone, on the function of the urinary bladder and the external urethral sphincter in anesthetized rats

BACKGROUND

A previous report showed that the atypical neuroleptic clozapine resulted in marked changes in urodynamic parameters and greatly inhibited the activity of the external urethral sphincter in anesthetized rats. Such findings may help explain the high incidence of urinary disturbances reported during clozapine therapy. In an effort to extend our observations to other atypical neuroleptic agents, the present study investigated the effects of two newer atypical antipsychotics, olanzapine and risperidone, on the bladder and external urethral sphincter during cystometry in anesthetized rats.

RESULTS

At a dose of 0.1 mg/kg (i.v.), olanzapine decreased the micturition volume and increased the residual volume. In addition, olanzapine decreased the expulsion time and the amplitude of the high frequency oscillations observed during the expulsion phase. Larger doses (1 mg/kg) had a greater effect. Olanzapine also reduced the activity recorded from the external urethral sphincter, and the bursting observed during the expulsion phase was abolished by 1.0 mg/kg. Risperidone had similar effects although the maximal effects were smaller than those observed with olanzapine. The amplitude of bladder contractions elicited by electrical stimulation of the pelvic nerve was reduced by olanzapine but not risperidone suggesting a possible anti-muscarinic peripheral effect of olanzapine.

CONCLUSIONS

Olanzapine and risperidone significantly altered several voiding parameters and decreased the activity of the external urethral sphincter in the anesthetized rat. We propose that these effects are due to the central action of these drugs and not to peripheral effects. These findings may explain some of the clinical reports of urinary incontinence with risperidone and may predict similar occurrences with olanzapine therapy.

Pharmacology of the lower urinary tract

The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the urinary bladder, urethra, and external urethral sphincter. This activity is in turn controlled by neural circuits in the brain, spinal cord, and peripheral ganglia. Various neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin, excitatory and inhibitory amino acids, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in the neural regulation of the lower urinary tract. Injuries or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce voiding dysfunctions such as urinary frequency, urgency, and incontinence or inefficient voiding and urinary retention. This chapter will review recent advances in our understanding of the pathophysiology of voiding disorders and the targets for drug therapy.

Fluvoxamine is ineffective in the treatment of enuresis in children and adolescents: an open-label pilot study

Tricyclic antidepressants possess established antienuretic properties. The selective serotonin reuptake inhibitors (SSRIs) have similar antidepressant properties to the tricyclic antidepressants and a safer side effect profile. The aim of the present study was to evaluate the antienuretic efficacy of one SSRI, fluvoxamine. Nine children aged 9 to 14 years with primary enuresis which was resistant to behavioral therapy participated in the study. All received fluvoxamine, 75-100 mg per day. In four, the enuresis was the only focus of clinical attention, and five received fluvoxamine for other primary indications. Enuresis was monitored daily, and mean voiding frequency was compared between three phases: baseline, on treatment and off treatment. Fluvoxamine had no statistically significant effect on enuresis. Fluvoxamine does not seem to possess significant antienuretic properties. We suggest that the combination of serotonergic with anticholinergic activity is a major factor in the antienuretic activity. In the treatment of children or adolescents with obsessive-compulsive disorder and comorbid enuresis, clomipramine may be preferred over SSRIs. Copyright 2001 John Wiley & Sons, Ltd.

The role of alpha(1)-adrenoceptors and 5-HT(1A) receptors in the control of the micturition reflex in male anaesthetized rats

1. The effects of the alpha(1)-adrenoceptor antagonists doxazosin (0.1 -- 2 mg kg(-1)), RS-100329 (alpha(1A); 0.01 -- 1 mg kg(-1)), RS-513815 (Ro 151-3815, alpha(1B); 0.3 -- 3 mg kg(-1)) and BMY 7378 (alpha(1D); 0.1 -- 1 mg kg(-1)), the 5-HT(1A) receptor agonist, 8-OH-DPAT (0.03 -- 0.3 mg kg(-1)) and antagonist WAY-100635 (0.03 -- 0.3 mg kg(-1)) were investigated (i.v.) on the 'micturition reflex' in the urethane anaesthetized male rat. 2. Reflex-evoked urethra contractions were most sensitive to the inhibitory action of RS-100329, followed by doxazosin, BMY 7378 and WAY-100635 and then RS-513815. The maximum inhibition was 66, 63, 54, 46 and 22% at doses of 0.3, 0.5, 0.3, 0.3 and 3 mg kg(-1) respectively. 3. BMY 7378 and 8-OH-DPAT decreased, while WAY-100635 increased, the pressure threshold to induce bladder contraction. WAY-100635 (0.01 mg kg(-1)) blocked the effects of BMY 7378 (1 mg kg(-1)) on bladder pressure and volume threshold. 4. Doxazosin, RS-100329 and BMY 7378 had a similar potency in inducing a fall in arterial blood pressure while WAY-100635 only caused a fall at the highest dose. 5. Therefore, reflex-evoked urethral contraction involves the activation of alpha(1A/1D)-adrenoceptors, as BMY 7378 and RS-100329 are similarly potent in attenuating this effect. The ability of WAY-100635 to attenuate this contraction may suggest that 5-HT(1A) receptors are also involved. However, as this inhibition occurred at the highest dose of WAY-100635, which also caused a fall in arterial blood pressure; this effect is considered to be due to blockade of alpha(1)-adrenoceptors not 5-HT(1A) receptors. Nevertheless the initiation of the 'micturition reflex' involves the activation of 5-HT(1A) receptors.