External Urethral Sphincter Electromyography Research Articles

External urethral sphincter electromyography in asymptomatic women and the influence of the menstrual cycle.

To investigate by electromyography (EMG), the presence of complex repetitive discharges (CRDs) and decelerating bursts (DBs) in the striated external urethral sphincter during the menstrual cycle in female volunteers with no urinary symptoms and complete bladder emptying. Healthy female volunteers aged 20-40 years, with regular menstrual cycles and no urinary symptoms were recruited. Volunteers completed a menstruation chart, urinary symptom questionnaires, pregnancy test, urine dipstick, urinary free flow and post-void ultrasound bladder scan. Exclusion criteria included current pregnancy, use of hormonal medication or contraception, body mass index of >35 kg/m(2) , incomplete voiding and a history of pelvic surgery. Eligible participants underwent an external urethral sphincter EMG, using a needle electrode in the early follicular phase and the mid-luteal phase of their menstrual cycles. Serum oestradiol and progesterone were measured at each EMG test. In all, 119 women enquired about the research and following screening, 18 were eligible to enter the study phase. Complete results were obtained in 15 women. In all, 30 EMG tests were undertaken in the 15 asymptomatic women. Sphincter EMG was positive for CRDs and DBs at one or both phases of the menstrual cycle in eight (53%) of the women. Three had CRDs and DBs in both early follicular and mid-luteal phases. Five had normal EMG activity in the early follicular phase and CRDs and DBs in the mid-luteal phase. No woman had abnormal EMG activity in the early follicular phase and normal activity in the luteal phase. There was no relationship between EMG activity and age, parity or serum levels of oestradiol and progesterone. CRDs and DB activity in the external striated urethral sphincter is present in a high proportion of asymptomatic young women. This abnormal EMG activity has been shown for the first time to change during the menstrual cycle in individual women. CRDs and DBs are more commonly found in the luteal phase of the menstrual cycle. The importance of CRDs and DBs in the aetiology of urinary retention in young women remains uncertain. The distribution and or quantity of abnormal EMG activity in the external urethral sphincter may be important. In a woman with urinary retention the finding of CRDs and DBs by needle EMG does not automatically establish Fowler's syndrome as the explanation for the bladder dysfunction. Urethral pressure profilometry may be helpful in establishing a diagnosis. Opiate use and psychological stress should be considered in young women with urinary retention.

A novel urodynamic model for lower urinary tract assessment in awake rats

To develop a urodynamic model incorporating external urethral sphincter (EUS) electromyography (EMG) in awake rats. Bladder catheters and EUS EMG electrodes were implanted in female Sprague Dawley rats. Assessments were performed in awake, lightly restrained rats on postoperative day 12-14. Measurements were repeated in the same rat on day 16 under urethane anaesthesia. Urodynamics and EUS EMG were performed simultaneously. In addition, serum creatinine and bladder histology was assessed. No significant differences in urodynamic parameters were found between bladder catheter only vs bladder catheter and EUS EMG electrode groups. Urethane anaesthesia evoked prominent changes in both urodynamic parameters and EUS EMG. Serum creatinine was within the normal limits in all rats. Bladder weight and bladder wall thickness were significantly increased in both the bladder catheter only and the bladder catheter and EUS EMG group compared with controls. Our novel urodynamic model allows repetitive measurements of both bladder and EUS function at different time points in the same rat under fully awake conditions and opens promising avenues to investigate lower urinary tract dysfunction in a translational approach.

MP8-16 CHRONIC BILATERAL PUDENDAL NERVE ELECTRICAL STIMULATION IMPROVES RECOVERY FROM SIMULATED CHILDBIRTH INJURY IN A STRESS URINARY INCONTINENCE MODEL

INTRODUCTION AND OBJECTIVES: The mechanism of stress urinary incontinence (SUI) development likely involves incomplete regeneration of the pudendal nerve and repair of the external urethral sphincter (EUS). Electrical stimulation (e-stim) can increase brain-derived neurotrophic factor expression, activate Schwann cells, and promote neuroregeneration after nerve injury. The aim of this study was to determine if bilateral pudendal nerve e-stim would facilitate recovery from SUI in a simulated childbirth injury model. METHODS: Forty virgin Sprague-Dawley female rats (250e300g) received either sham injury or pudendal nerve crush (PNC) þ vaginal distension (VD) to establish a SUI model. Immediately after injury, electrodes were implanted at the pudendal nerve bilaterally. Each animal underwent sham e-stim, twice per week e-stim, or daily estim for 2 wk with subthreshold stimulation parameters (20Hz frequency, 0.1ms pulse duration, 0.3mA current). Two weeks after injury and treatment, each animal underwent leak point pressure (LPP) testing with EUS electromyography (EMG), and pudendal nerve sensory branch potential (PNSBP) recordings and was then euthanized for histology. RESULTS: Two wk after injury, LPP was significantly increased in both 2/wk e-stim and daily e-stim compared to sham e-stim. Daily estim significantly increased LPP compared to 2/wk e-stim. However, all stimulated groups had significantly decreased LPP compared to either sham injury with no electrode implant or sham injury with sham e-stim. EUS EMG and PNSBP were significantly decreased after injury with sham e-stim compared to either sham injury with no implant or sham injury with sham e-stim, but not with 2/wk e-stim and daily e-stim, indicating improved recovery after e-stim. Histology revealed that 2 wk after injury, density and morphology of pudendal nerve axons were significantly decreased compared to sham injury with no electrode implant, but improved after 2/wk and daily e-stim. Neuromuscular junction innervation was significantly decreased after injury, but improved after 2/wk and daily e-stim. Masson’s trichrome revealed that morphology of the EUS significantly decreased compared to sham injury, but improved with 2/wk and daily e-stim. CONCLUSIONS: This study demonstrates that chronic bilateral e-stim to the pudendal nerve is feasible and can accelerate recovery in a model of SUI. Daily e-stim provides better preservation of urethral function than twice per week e-stim.

Spinal stimulation of the upper lumbar spinal cord modulates urethral sphincter activity in rats after spinal cord injury.

After spinal cord injury (SCI), the neurogenic bladder is observed to develop asynchronous bladder and external urethral sphincter (EUS) contractions in a condition known as detrusor-sphincter dyssnergia (DSD). Activation of the EUS spinal controlling center located at the upper lumbar spinal cord may contribute to reduce EUS dyssynergic contractions and decrease urethral resistance during voiding. However, this mechanism has not been well studied. This study aimed at evaluating the effects of epidural stimulation (EpS) over the spinal EUS controlling center (L3) in combination with a serotonergic receptor agonist on EUS relaxation in naive rats and chronic (6-8 wk) T8 SCI rats. Cystometrogram and EUS electromyography (EMG) were obtained before and after the intravenous administration of 5HT-1A receptor agonist and antagonist. The latency, duration, frequency, amplitude, and area under curve of EpS-evoked EUS EMG responses were analyzed. EpS on L3 evoked an inhibition of EUS tonic contraction and an excitation of EUS intermittent bursting/relaxation correlating with urine expulsion in intact rats. Combined with a 5HT-1A receptor agonist, EpS on L3 evoked a similar effect in chronic T8 SCI rats to reduce urethral contraction (resistance). This study examined the effect of facilitating the EUS spinal controlling center to switch between urine storage and voiding phases by using EpS and a serotonergic receptor agonist. This novel approach of applying EpS on the EUS controlling center modulates EUS contraction and relaxation as well as reduces urethral resistance during voiding in chronic SCI rats with DSD.

Quantitative EMG of external urethral sphincter in neurologically healthy men with prostate pathology

There are no data on quantitative electromyography (EMG) of the external urethral sphincter (EUS) in men. The aim of this study was to obtain reference data from a group of neurologically healthy continent men with prostate pathology using a standardized technique. Sixty-six subjects without neurological disorders were included. Motor unit potential (MUP) and interference pattern (IP) analysis were performed using multi-MUP and turns/amplitude techniques, respectively. Of 66 patients, 51 (mean age, 65.17; SD, 6.70) had localized prostate cancer (PCa), and 15 (mean age 61.67, SD 6.25) had benign prostate hyperplasia (BPH). Descriptive MUP parameters and IP-clouds were obtained, respectively in the BPH and PCa groups. No group differences were found. This study provides quantitative EMG measures of EUS functionality in continent men with prostate pathology. The data could be used as reference values for patients undergoing prostate surgery to identify postoperative changes in EUS function possibly influencing continence.

Combined Cystometrography and Electromyography of the External Urethral Sphincter Following Complete Primary Repair of Bladder Exstrophy

Concern in patients with bladder exstrophy after reconstruction regarding potential injury to pelvic neurourological anatomy and a resultant functional deficit prompted combined (simultaneous) cystometrography and electromyography after complete primary repair of bladder exstrophy. We determined whether complete primary repair of bladder exstrophy would adversely affect the innervation controlling bladder and external urethral sphincter function. Complete primary repair of bladder exstrophy was performed via a modified Mitchell technique in newborns without osteotomy. Postoperative evaluation included combined cystometrography and needle electrode electromyography via the perineum, approximating the external urethral sphincter muscle complex. Electromyography was done to evaluate the external urethral sphincter response to sacral reflex stimulation and during voiding. Nine boys and 4 girls underwent combined cystometrography/electromyography after complete primary repair of bladder exstrophy. Age at study and time after complete primary repair of bladder exstrophy was 3 months to 10 years (median 11.5 months). Cystometrography revealed absent detrusor overactivity and the presence of a sustained detrusor voiding contraction in all cases. Electromyography showed universally normal individual motor unit action potentials of biphasic pattern, amplitude and duration. The external urethral sphincter sacral reflex response was intact with a normal caliber with respect to Valsalva, Credé, bulbocavernosus and anocutaneous (bilateral) stimulation. Synergy was documented by abrupt silencing of external urethral sphincter electromyography activity during voiding. After complete primary repair of bladder exstrophy combined cystometrography/electromyography in patients with bladder exstrophy showed normal neurourological findings, including sacral reflex responses, sustained detrusor voiding contraction and synergic voiding, in all patients postoperatively. These findings confirm the safety of complete primary repair of bladder exstrophy. Based on our results we have discontinued routine electromyography in these patients.

Long-term effects of simulated childbirth injury on function and innervation of the urethra

Pudendal nerve and external urethral sphincter (EUS) injury during vaginal delivery are risk factors for stress urinary incontinence (SUI). Although most patients with short-term postpartum SUI regain continence within 1 year, they have a higher predisposition to develop recurrent SUI years later, suggesting a possible mechanistic relationship. In contrast, animal models generally recover spontaneously and have not been studied much in the long term. The aim of this study was to investigate the long-term effects of simulated childbirth injury in rats. Thirty-four Sprague-Dawley female rats underwent sham injury or pudendal nerve crush and vaginal distension (PNC + VD), a simulated childbirth injury. Nine weeks later, leak point pressure (LPP) and EUS electromyography (EMG) were recorded simultaneously. The pudendal nerve was harvested for histological analysis. EUS neuromuscular junctions (NMJs) and their innervation were qualitatively assessed using immunofluorescence. A t-test was used to compare quantitative outcomes between groups, with P < 0.05 indicating a significant difference. There was no significant difference in LPP or EUS EMG amplitude or firing rate between the two groups. Nonetheless after PNC + VD, NMJs in the EUS were diffuse and were innervated by tortuous and multiple axons, demonstrating that reinnervation of the EUS was still in progress. Although continence function recovered 9 weeks after simulated childbirth injury, innervation of EUS was not complete at this time point, suggestive of persistent neurogenic deficiency which when compounded by the effects of aging may lead to a delayed recurrence of SUI in this animal model with increased age.

Combined Cystometrography and Electromyography of the External Urethral Sphincter Following Complete Primary Repair of Bladder Exstrophy

Combined Cystometrography and Electromyography of the External Urethral Sphincter Following Complete Primary Repair of Bladder Exstrophy

Sexually dimorphic urethral activity in response to pharmacological activation of 5-HT1A receptors in the rat

In this study, we examined the possibility that 5-HT1A receptors may underlie sexually dimorphic mechanisms affecting the regulation of urethral functions in anesthetized rats. Simultaneous recordings of intravesical pressure under isovolumetric conditions, external urethral sphincter-electromyography, and urethral perfusion pressure were used to examine the effects of a 5-HT1A receptor agonist [8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)] and antagonist (WAY-100635) on bladder and urethral functions. This research also evaluated the effects of 8-OH-DPAT and α-bungarotoxin (a neuromuscular blockade agent) on urethral continence using leak point pressure testing, and the distribution of 5-HT1A receptors in the lower urinary tract was assessed by immunohistochemistry. The serotonergic mechanism that controls the urinary bladder and external urethral sphincter-electromyography activity showed no significant sexual differences, but urethral activity in urethral perfusion pressure and leak point pressure values exhibited some sexual differences. 8-OH-DPAT enhanced urethral pressure during continence in rats of both sexes, but the drug elevated the pressure during voiding in male rats and reduced it in female rats. The distribution of 5-HT1A receptors in the spinal cord also showed some sexual differences. The present study contributes to our understanding of the role of 5-HT1A receptors in physiological and immunohistochemical properties of urethral smooth muscle in rats of different sexes. These findings may be a basis for the future development of pharmacotherapies for stress urinary incontinence in men.

Serotonergic 5-HT1A receptor agonist (8-OH-DPAT) ameliorates impaired micturition reflexes in a chronic ventral root avulsion model of incomplete cauda equina/conus medullaris injury

Trauma to the thoracolumbar spine commonly results in injuries to the cauda equina and the lumbosacral portion of the spinal cord. Both complete and partial injury syndromes may follow. Here, we tested the hypothesis that serotonergic modulation may improve voiding function after an incomplete cauda equina/conus medullaris injury. For this purpose, we used a unilateral L5–S2 ventral root avulsion (VRA) injury model in the rat to mimic a partial lesion to the cauda equina and conus medullaris. Compared to a sham-operated series, comprehensive urodynamic studies demonstrated a markedly reduced voiding efficiency at 12weeks after the VRA injury. Detailed cystometrogram studies showed injury-induced decreased peak bladder pressures indicative of reduced contractile properties. Concurrent external urethral sphincter (EUS) electromyography demonstrated shortened burst and prolonged silent periods associated with the elimination phase. Next, a 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), was administered intravenously at 12weeks after the unilateral L5–S2 VRA injury. Both voiding efficiency and maximum intravesical pressure were significantly improved by 8-OH-DPAT (0.3–1.0mg/kg). 8-OH-DPAT also enhanced the amplitude of EUS tonic and bursting activity as well as duration of EUS bursting and silent period during EUS bursting. The results indicate that 8-OH-DPAT improves voiding efficiency and enhances EUS bursting in rats with unilateral VRA injury. We conclude that serotonergic modulation of the 5-HT1A receptor may represent a new strategy to improve lower urinary tract function after incomplete cauda equina/conus medullaris injuries in experimental studies.

Pudendal Nerve Stretch Reduces External Urethral Sphincter Activity in Rats

Most animal models of stress urinary incontinence simulate maternal injuries of childbirth since delivery is a major risk factor but they do not reproduce the nerve stretch known to occur during human childbirth. We hypothesized that pudendal nerve stretch produces reversible dysfunction of the external urethral sphincter. Female virgin Sprague-Dawley® rats were anesthetized with urethane. Bilateral pudendal nerve stretch or sham injury was performed for 5 minutes. External urethral sphincter electromyography and leak point pressure were recorded immediately before and after, and 10, 30, 60 and 120 minutes after pudendal nerve stretch. Post-pudendal nerve stretch results were compared to prestretch values and to values in sham injured animals. The pudendal nerves underwent qualitative histological assessment. The nucleus of Onuf was evaluated by immunohistochemistry and polymerase chain reaction for β-APP and c-Fos expression as markers of neuronal activity and injury. A total of 14 rats underwent bilateral pudendal nerve stretch (9) or sham injury (5). Each nerve was stretched a mean ± SEM of 74% ± 18% on the left side and 63% ± 13% on the right side. Electromyography amplitude decreased significantly immediately after stretch compared to before stretch and after sham injury (p = 0.003) but it recovered by 30 minutes after stretch. There was no significant change in leak point pressure at any time. Two hours after injury histology showed occasional neuronal degeneration. β-APP and c-Fos expression was similar in the 2 groups. Acute pudendal nerve stretch produces reversible electrophysiological dysfunction but without leak point pressure impairment. Pudendal nerve stretch shows promise in modeling injury. It should be tested as part of a multi-injury, chronic, physiological model of human childbirth injury.

Neurotrophin therapy improves recovery of the neuromuscular continence mechanism following simulated birth injury in rats.

Stress urinary incontinence (SUI) affects women both acutely and chronically after vaginal delivery. Current SUI treatments assume the neuromuscular continence mechanism, comprised of the pudendal nerve (PN) and external urethral sphincter (EUS), is either intact or irreparable. This study investigated the ability of neurotrophin therapy to facilitate recovery of the neuromuscular continence mechanism. Virgin, Sprague Dawley rats received simulated childbirth injury or sham injury and treatment with continuous infusion of brain-derived neurotrophic factor (BDNF) or saline placebo to the site of PN injury. Continence was assessed by leak point pressure (LPP) and EUS electromyography (EMG) 14 and 21 days after injury. Structural recovery was assessed histologically. Molecular assessment of the muscular and neuroregenerative response was determined via measurement of EUS BDNF and PN β(II) -tubulin expression respectively, 4, 8, and 12 days after injury. Following injury, LPP was significantly reduced with saline compared to either BDNF treatment or sham injury. Similarly, compared to sham injury, resting EUS EMG amplitude and firing rate, as well as amplitude during LPP were significantly reduced with saline but not BDNF treatment. Histology confirmed improved EUS recovery with BDNF treatment. EUS BDNF and PN β(II)-tubulin expression demonstrated that BDNF treatment improved the neurogenerative response and may facilitate sphincteric recovery. Continuous targeted neurotrophin therapy accelerates continence recovery after simulated childbirth injury likely through stimulating neuroregeneration and facilitating EUS recovery and re-innervation. Neurotrophins or other therapies targeting neuromuscular regeneration may be useful for treating SUI related to failure of the neuromuscular continence mechanism.

1362 ELECTRICAL STIMULATION OF THE PUDENDUAL NERVE PROMOTES FUNCTIONAL RECOVERY AFTER SIMULATED BIRTH INJURY

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Incontinence - Evaluation & Therapy III1 Apr 20121362 ELECTRICAL STIMULATION OF THE PUDENDUAL NERVE PROMOTES FUNCTIONAL RECOVERY AFTER SIMULATED BIRTH INJURY Hai-Hong Jiang, Raul Juarez, Yolanda Cruz, and Margot Damaser Hai-Hong JiangHai-Hong Jiang Cleveland, OH More articles by this author , Raul JuarezRaul Juarez Cleveland, OH More articles by this author , Yolanda CruzYolanda Cruz Cleveland, OH More articles by this author , and Margot DamaserMargot Damaser Cleveland, OH More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1745AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Birth injury is one of important factor for female stress urinary incontinence (SUI), while urethra function for continence can be impaired during the vaginal delivery due to compression to urethra as well as pudendal nerve. We demonstrated that electrical stimulation of the pudendal nerve after simulated childbirth upregulates brain derived neurotrophic factor (BDNF) expression in Onuf's nucleus in previous study. In this further study, we investigates the effects of pudendal nerve electrical stimulation on recovery of urinary continence following simulated childbirth, vaginal distension (VD) and pudendal nerve crush (PNC). METHODS The Sprague-Dawley female rats (n=24, 225-250g) were assigned to 3 groups of the simulated birth injury plus electrical stimulation (I&E, n=8), the injury plus sham electrical stimulation (I&S, n=8), and sham injury plus sham electrical stimulation (S&S, n=8). Rats in I&E and I&S groups underwent 4 hours of VD followed by bilateral PNC. Rats in I&E received 1 hour of bilateral electrical stimulation (20 Hz, 0.3mA, 0.1 ms duration) of the pudendal nerve proximal to the crush site immediately after PNC and 2 times per week for 2 weeks, when urethral function was assessed via leak point pressure (LPP) and simultaneous external urethral sphincter (EUS) electromyography (EMG) using a transurethral catheter and needle wire electrodes. Rats in I&S received VD and PNC followed by sham stimulation immediately and 2 times per week. S&S received the same procedures but without balloon distension, pudendal nerve crush, or electrical stimulation. A 2 way ANOVA was used to analyze the results, with the 2 factors of dual injury and electrical stimulation. P<0.05 indicated a significant difference between groups. RESULTS Two weeks after injury, simulated birth injury significantly decreased both LPP and amplitude of EUS EMG (p<0.05) while electrical stimulation significantly increased LPP and amplitude of EUS EMG (p<0.05). Simulated birth injury significantly decreased EUS EMG firing rate but electrical stimulation did not significantly improve it. CONCLUSIONS The results suggest that bilateral electrical stimulation immediately facilitates recovery of continence after simulated birth injury. Based on our previous work, we suggest it does so by increasing expression of neurotrophins, particularly BDNF, in Onuf's nucleus. We conclude that electrical stimulation has potential as a preventative paradigm for SUI to facilitate recovery of continence after birth. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e552-e553 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hai-Hong Jiang Cleveland, OH More articles by this author Raul Juarez Cleveland, OH More articles by this author Yolanda Cruz Cleveland, OH More articles by this author Margot Damaser Cleveland, OH More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

1353 RECOVERY OF THE NEUROMUSCULAR CONTINENCE MECHANISM IS IMPROVED BY NEUROTROPHIN TREATMENT AFTER SIMULATED BIRTH INJURY IN RATS

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Incontinence - Evaluation & Therapy III1 Apr 20121353 RECOVERY OF THE NEUROMUSCULAR CONTINENCE MECHANISM IS IMPROVED BY NEUROTROPHIN TREATMENT AFTER SIMULATED BIRTH INJURY IN RATS Bradley Gill, Charuspong Dissaranan, Hai-Hong Jiang, Brian Balog, Danli Lin, and Margot Damaser Bradley GillBradley Gill Cleveland, OH More articles by this author , Charuspong DissarananCharuspong Dissaranan Cleveland, OH More articles by this author , Hai-Hong JiangHai-Hong Jiang Cleveland, OH More articles by this author , Brian BalogBrian Balog Cleveland, OH More articles by this author , Danli LinDanli Lin Cleveland, OH More articles by this author , and Margot DamaserMargot Damaser Cleveland, OH More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1736AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Both acutely and long after childbirth, inadequacy of the neuromuscular continence mechanism comprised of the pudendal nerve (PN) and external urethral sphincter (EUS) has been implicated in Stress Urinary Incontinence (SUI) pathogenesis. Neurotrophins such as brain-derived neurotrophic factor (BDNF) are upregulated by innervated target organs after nerve injury to retrogradely stimulate neuroregeneration. However, concurrent EUS trauma from childbirth opposes the effects of PN injury on EUS BDNF upregulation. This study investigated functional and neuroregenerative responses of the neuromuscular continence mechanism to PN neurotrophin treatment after simulated childbirth injury. METHODS Age-matched virgin Sprague-Dawley rats underwent either untreated sham PN injury or simulated childbirth injury via PN crush and vaginal distention immediately treated with a 14-day infusion of either BDNF or saline placebo to the PN injury site. The neuromuscular continence mechanism was assessed 14 and 21 days after injury using leak point pressure (LPP) and EUS electromyography (EMG). The PN neuroregenerative response, indicated by cytoskeletal protein βII-tubulin expression, and EUS expression of BDNF were assessed by PCR 4, 8, and 12 days after injury with immunofluorescence utilized to confirm protein expression and EUS histology assessed as well. RESULTS LPP was significantly decreased with saline compared to BDNF treatment or sham injury 14 days after injury. Compared to sham injury, EUS EMG amplitude during LPP and at rest was reduced significantly with saline but not BDNF treatment 14 days after injury, as was resting EUS EMG firing rate. There were no significant EMG differences between groups 21 days after injury. EUS BDNF and PN βII-tubulin expression suggested BDNF improved the PN neurogenerative response and facilitated EUS recovery and re-innervation while saline did not. Compared to sham injury, histology revealed less atrophy and fibrosis in the EUS with BDNF than saline. CONCLUSIONS Continuous, targeted, neurotrophin therapy accelerated functional recovery of the neuromuscular continence mechanism after simulated childbirth injury. A combined stimulation of PN neuroregeneration and EUS recovery and re-innervation likely occurred. Neurotrophin treatment or targeted upregulation of neurotrophin expression may be useful for treating SUI in women. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e549 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bradley Gill Cleveland, OH More articles by this author Charuspong Dissaranan Cleveland, OH More articles by this author Hai-Hong Jiang Cleveland, OH More articles by this author Brian Balog Cleveland, OH More articles by this author Danli Lin Cleveland, OH More articles by this author Margot Damaser Cleveland, OH More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

120 MESENCHYMAL STEM CELL (MSC) SECRETED FACTORS FACILITATE PUDENDAL NERVE (PN) RECOVERY AFTER SIMULATED CHILDBIRTH INJURY

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research II1 Apr 2012120 MESENCHYMAL STEM CELL (MSC) SECRETED FACTORS FACILITATE PUDENDAL NERVE (PN) RECOVERY AFTER SIMULATED CHILDBIRTH INJURY Charuspong Dissaranan, Emily Holthaus, Michelle Cruz, Brian Balog, Matthew Kiedrowski, Marc Penn, Howard Goldman, and Margot Damaser Charuspong DissarananCharuspong Dissaranan Cleveland, OH More articles by this author , Emily HolthausEmily Holthaus Cleveland, OH More articles by this author , Michelle CruzMichelle Cruz Cleveland, OH More articles by this author , Brian BalogBrian Balog Cleveland, OH More articles by this author , Matthew KiedrowskiMatthew Kiedrowski Akron, OH More articles by this author , Marc PennMarc Penn Akron, OH More articles by this author , Howard GoldmanHoward Goldman Cleveland, OH More articles by this author , and Margot DamaserMargot Damaser Cleveland, OH More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.168AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES During vaginal delivery the external urethral sphincter (EUS) and its innervation, the PN, can be injured, resulting in stress urinary incontinence. Even 5 years after injury recovery is poor. Previous studies have demonstrated that bone marrow-derived stem cells improve growth and myelination of regenerating axons which may be due to the release of trophic factors. This study investigates if intravenously (IV) injected MSC home to the PN and the EUS and facilitate functional recovery via secretion of paracrine factors after PN crush (PNC). METHODS Age-matched virgin female rats were utilized in 3 experiments: 1. The functional study utilizing MSC had 3 groups: PNC receiving IV phosphate buffered saline (PBS; N=6); PNC receiving 2 million GFP-labeled MSC IV (N=6); and sham PNC receiving IV PBS (N=6). 2. The functional study utilizing media that had been conditioned by MSC and then concentrated (CCM) had 3 groups: PNC receiving CCM by local injection to the crush site of the PN (N=6); PNC receiving local control media injection (N=6); and sham PNC receiving local control media injection (N=6). 3. The homing study had 2 groups: PNC receiving IV MSC (N=11) and sham PNC receiving IV MSC (N=11). All treatments were delivered 1 hour after injury. Urethral function was tested 10 days after injury by simultaneous leak point pressure (LPP) and EUS electromyography (EMG). Mean frequency and amplitude of EUS EMG both at rest and during LPP were calculated. The PN, urethra, vagina, rectum and spleen were harvested and imaged ex-vivo for GFP 2 and 4 days after injection in the homing study. RESULTS LPP was significantly reduced in rats with PNC treated with PBS or control media compared to sham PNC but not in those given IV MSCs or CCM. Similarly, EUS EMG frequency and amplitude were significantly decreased in rats with PNC treated with PBS or control media compared to sham PNC but not in PNC rats treated with IV MSC or CCM. Ex vivo imaging showed significantly increased fluorescence, indicating more MSCs, in the PN and spleen of PNC rats receiving IV MSC. CONCLUSIONS IV infused MSC home to the PN and spleen and facilitate recovery of the PN and continence after simulated childbirth injury. CCM injection locally gave similar results. The mechanism of action leading to restored continence is potentially via secreted paracrine factors. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e48-e49 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Charuspong Dissaranan Cleveland, OH More articles by this author Emily Holthaus Cleveland, OH More articles by this author Michelle Cruz Cleveland, OH More articles by this author Brian Balog Cleveland, OH More articles by this author Matthew Kiedrowski Akron, OH More articles by this author Marc Penn Akron, OH More articles by this author Howard Goldman Cleveland, OH More articles by this author Margot Damaser Cleveland, OH More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Selective Activation of the Muscles of Micturition Using Intrafascicular Stimulation of the Pudendal Nerve

We investigate the hypothesis that intrafascicular stimulation of the pudendal nerve (PN) can be used to selectively activate the detrusor bladder muscle and the external urethral sphincter (EUS). Nine anesthetized male canines were used in this study. Muscle activations were measured via bladder catheter pressure transducers and EUS electromyography (EMG) wires. The PNs were exposed via dissection of the ischioanal fossa and implanted with Utah Slanted Electrode Arrays (USEAs). USEAs consist of 100, 0.5–1.5 mm long microelectrodes that project out from a 4 $\,\times\,$ 4 mm substrate. Intrafascicular stimulation was delivered via individual USEA microelectrodes in order to map the ability of each electrode to selectively or nonselectively evoke detrusor and/or EUS contractions. We were able to selectively activate the detrusor using 33 Hz stimulation of PN axons with an average of $4.57 \pm 3.82$ ( ${\rm mean }\pm {\rm sd}$ ) USEA electrodes per animal tested. Electrically-evoked and distention-evoked bladder contractions had similar kinetics. Sustained bladder contractions were evoked via 60 s of intrafascicular stimulation. The EUS was activated using 33 Hz stimulation via an average of $26.14 \pm 19.45$ electrodes per animal tested. High frequency ( $> {2}~{\rm kHz}$ ) stimulation delivered via EUS selective electrodes produced nonselective block of PN axons. Examples of how this selective axonal access could be used to restore continence and activate micturition were demonstrated in two animals. We report herein the first study demonstrating selective detrusor and EUS activation via microelectrodes implanted intrafascicularly in the PN. Such selective activation enables new therapeutic possibilities for controlling the muscles of micturition.

Systemic administration of fluorogold for anatomical pre‐labeling of autonomic and motor neurons in the rat spinal cord compromises urodynamic recordings in acute but not long‐term studies

The use of anatomical tracer injections into peripheral tissues for retrograde labeling of spinal cord neurons may compromise physiological experiments in combined functional and morphological studies. We investigated whether a systemic injection of a retrogradely transported tracer, fluorogold (FG), may provide an alternative to direct injections into end organs for combined anatomical and physiological studies of the lower urinary tract. Urodynamic studies including cystometrogram recordings and external urethral sphincter electromyography were used as functional outcome measures. Pre-labeling of spinal cord neurons by intraperitoneal (i.p.) administration of FG resulted in a transient decrease in voiding efficiency, increase in resting pressure as well as increase in bladder size and weight at 5-7 days after the tracer administration. In contrast, there were no urodynamic or end-organ effects detected at 6-8 weeks after the i.p. injection of FG. We suggest that pre-labeling of spinal autonomic and motor neurons using i.p. administration of FG may be a useful tool when combining anatomical and functional outcome measures in long-term but not acute studies.

Improving voiding efficiency in the diabetic rat by a 5‐HT1A serotonin receptor agonist

Serotonin affects micturition in the normal rat through actions not only on ascending and descending spinal pathways and supraspinal centers but also on the lumbosacral spinal cord level. The selective 5-HT1A receptor agonist, 8-OH-DPAT((R)-(+)-8-hydroxy-2-(di-n-propylamino) tetralin), reversed detrusor-sphincter dyssynergia (DSD) in the spinal cord injury (SCI) rat. Rats with experimental diabetes mellitus (DM) have been shown to have both bladder and urethral dysfunction during reflex voiding. We therefore examined the effects of 8-OH-DPAT on micturition in DM rats. Female Sprague-Dawley rats were used. DM was induced by an intraperitoneal injection of streptozotocin (STZ, 65 mg/kg) and a cystometric study was performed 8 weeks post-injection. External urethral sphincter electromyography (EUS-EMG) was also measured. The 5-HT1A antagonist WAY-100635(N-tert-butyl-3-(4-(2-methoxyphenyl)-piperazin-1-yl)-2-phenylpropanamide) was administered after each 8-OH-DPAT dose-response. Compared to controls, DM rats had a higher bladder capacity, residual volume, and a lower voiding efficiency. In DM rats, 8-OH-DPAT (3-1,000 µg/kg, i.v.) induced significant dose-dependent increases in micturition volume, and decreases in residual volume, resulting in increases in voiding efficiency. During the micturition, there was a dose-dependent increased phasic EUS activity correlated with the improved voiding efficiency. WAY-100635 (300 µg/kg, i.v.) reversed the 8-OH-DPAT-induced changes. Both the bladder voiding efficiency and the periodic EUS activity were decreased in DM rats. 5-HT1A receptor agonism promoted periodic EUS activity, thereby improving voiding efficiency. Whether or not these results may have implications for the future treatment of voiding dysfunction in DM patients remains to be studied.

176 INTRAVENOUS MESENCHYMAL STEM CELLS HOME TO THE URETHRA AND FACILITATE RECOVERY FROM STRESS URINARY INCONTINENCE AFTER CHILDBIRTH INJURY VIA LOCAL SECRETION OF PARACRINE FACTORS

You have accessJournal of UrologyStem Cell Research1 Apr 2011176 INTRAVENOUS MESENCHYMAL STEM CELLS HOME TO THE URETHRA AND FACILITATE RECOVERY FROM STRESS URINARY INCONTINENCE AFTER CHILDBIRTH INJURY VIA LOCAL SECRETION OF PARACRINE FACTORS Charuspong Dissaranan, Michelle Cruz, Bradley Gill, Levilester Salcedo, Anne Cotleur, Raul Mendieta, Brian Balog, Matt Kiedrowski, Marc Penn, Howard Goldman, and Margot Damaser Charuspong DissarananCharuspong Dissaranan Cleveland, OH More articles by this author , Michelle CruzMichelle Cruz Cleveland, OH More articles by this author , Bradley GillBradley Gill Cleveland, OH More articles by this author , Levilester SalcedoLevilester Salcedo Cleveland, OH More articles by this author , Anne CotleurAnne Cotleur Cleveland, OH More articles by this author , Raul MendietaRaul Mendieta Cleveland, OH More articles by this author , Brian BalogBrian Balog Cleveland, OH More articles by this author , Matt KiedrowskiMatt Kiedrowski Cleveland, OH More articles by this author , Marc PennMarc Penn Cleveland, OH More articles by this author , Howard GoldmanHoward Goldman Cleveland, OH More articles by this author , and Margot DamaserMargot Damaser Cleveland, OH More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.245AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Vaginal delivery injures the nerves, muscle, and connective tissues responsible for maintaining continence and is a risk factor for the development of Stress Urinary Incontinence (SUI). We have previously demonstrated that stem cell homing cytokine MCP-3, and its receptors, are upregulated in urethral tissue after childbirth injury. Recent studies suggest stem cells may facilitate repair by secreting proteins that have paracrine effects. This study investigated whether stem cells homed to the urethra after childbirth injury and facilitated functional recovery of the urethral sphincter. Specifically, the aim of this study was to determine if intravenous (IV) bone marrow-derived mesenchymal stem cells (MSCs) improved urethral sphincter function compared to local administration of concentrated conditioned media (CCM) containing growth factors produced by the cells. METHODS Age-matched virgin female rats were divided into 6 groups: Vaginal Distension (VD) and IV saline (N=6), VD and IV MSCs (N=7), sham VD and IV saline (N=5), VD and CCM direct sphincter injection (N=5), VD and control media injection (N=4) and sham VD and control media injection (N=5). VD was done as previously described. One hour after injury, 2 million GFP-labeled MSCs or saline was injected via tail vein. MSC conditioned media was concentrated (CCM) and injected directly into the urethra. Outcomes were tested 1 week after injury by simultaneous leak point pressure (LPP) and external urethral sphincter (EUS) electromyography (EMG). Mean frequency and amplitude of 1 sec EUS EMG segments both at rest and during LPP were analyzed. Urethras and vaginas were harvested and imaged ex-vivo for MSCs GFP. RESULTS Continence (LPP) was significantly reduced in VD rats treated with saline or control media compared to sham VD but not in those given IV MSCs or CCM. EUS EMG frequency and amplitude, as well as LPP were significantly decreased in all VD rats, regardless of treatment, compared to sham VD. GFP imaging showed increased fluorescence, indicating MSCs, in the urethra and vagina of VD rats receiving IV MSCs. CONCLUSIONS IV MSCs home to the urethra and facilitate recovery of continence after childbirth injury, but not by increasing EUS function. Therefore, improved LPP likely results from the local secretion of paracrine factors by MSCs. The exact mechanism of action leading to restored continence requires further investigation. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byGill B, Damaser M, Vasavada S and Goldman H (2018) Stress Incontinence in the Era of Regenerative Medicine: Reviewing the Importance of the Pudendal NerveJournal of Urology, VOL. 190, NO. 1, (22-28), Online publication date: 1-Jul-2013. Volume 185Issue 4SApril 2011Page: e73 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Charuspong Dissaranan Cleveland, OH More articles by this author Michelle Cruz Cleveland, OH More articles by this author Bradley Gill Cleveland, OH More articles by this author Levilester Salcedo Cleveland, OH More articles by this author Anne Cotleur Cleveland, OH More articles by this author Raul Mendieta Cleveland, OH More articles by this author Brian Balog Cleveland, OH More articles by this author Matt Kiedrowski Cleveland, OH More articles by this author Marc Penn Cleveland, OH More articles by this author Howard Goldman Cleveland, OH More articles by this author Margot Damaser Cleveland, OH More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Quantification of external urethral sphincter and bladder activity during micturition in the intact and spinally transected adult rat

The goal of this study was to determine the effect of chronic mid-thoracic spinal cord transection on the time course of external urethral sphincter (EUS) and bladder activity associated with micturition events in the rat. Adult female Sprague–Dawley rats, either spinally intact or transected (T 9–T 10), were anesthetized with urethane and set up for continuous flow urodynamic recording of bladder intravesical pressure (BP) and EUS electromyography (EMG). Spinal transections were performed under isoflurane anesthesia 1–8 weeks prior to the terminal experiment. Four major differences between intact and transected rats were observed: 1) While the frequency of micturition events in the intact rat was dependent upon the rate of bladder filling, the bladder contraction and associated EUS activation in transected rats exhibited an intrinsic rhythm that was independent of the rate of bladder filling and post-transection survival time. 2) EUS activation was augmented at the beginning of active bladder contraction in the transected rat, indicating an amplified guarding reflex. 3) Phasic EUS activity at the peak of bladder contraction (EUS bursting) in the intact rat was markedly reduced or absent in the transected rat. 4) The sustained tonic EUS activity following bladder relaxation in the intact rat was absent in the transected rat. These data are discussed in the context of understanding the pathophysiology of spinal cord injury (SCI) induced destrusor-sphincter dyssynergia (DSD).