Model-based analysis of the acute effects of transcutaneous magnetic spinal cord stimulation on micturition after spinal cord injury in humans.

AIM: After spinal cord injuries (SCIs), patients may develop either detrusor-sphincter dyssynergia (DSD) or urinary incontinence, depending on the level of the spinal injury. DSD and incontinence reflect the loss of coordinated neural control among the detrusor muscle, which increases bladder pressure to facilitate urination, and urethral sphincters and pelvic floor muscles, which control the bladder outlet to restrict or permit bladder emptying. Transcutaneous magnetic stimulation (TMS) applied to the spinal cord after SCI reduced DSD and incontinence. We defined, within a mathematical model, the minimum neuronal elements necessary to replicate neurogenic dysfunction of the bladder after a SCI and incorporated into this model the minimum additional neurophysiological features sufficient to replicate the improvements in bladder function associated with lumbar TMS of the spine in patients with SCI. METHODS: We created a computational model of the neural circuit of micturition based on Hodgkin-Huxley equations that replicated normal bladder function. We added interneurons and increased network complexity to reproduce dysfunctional micturition after SCI, and we increased the density and complexity of interactions of both inhibitory and excitatory lumbar spinal interneurons responsive to TMS to provide a more diverse set of spinal responses to intrinsic and extrinsic activation of spinal interneurons that remains after SCI. RESULTS: The model reproduced the re-emergence of a spinal voiding reflex after SCI. When we investigated the effect of monophasic and biphasic TMS at two frequencies applied at or below T10, the model replicated the improved coordination between detrusor and external urethral sphincter activity that has been observed clinically: low-frequency TMS (1 Hz) within the model normalized control of voiding after SCI, whereas high-frequency TMS (30 Hz) enhanced urine storage. CONCLUSION: Neuroplasticity and increased complexity of interactions among lumbar interneurons, beyond what is necessary to simulate normal bladder function, must be present in order to replicate the effects of SCI on control of micturition, and both neuronal and network modifications of lumbar interneurons are essential to understand the mechanisms whereby TMS reduced bladder dysfunction after SCI.

In Silico Electrophysiological Investigation of Transient Receptor Potential Melastatin-4 Ion Channel Biophysics to Study Detrusor Overactivity.

Enhanced electrical activity in detrusor smooth muscle (DSM) cells is a key factor in detrusor overactivity which causes overactive bladder pathological disorders. Transient receptor potential melastatin-4 (TRPM4) channels, which are calcium-activated cation channels, play a role in regulating DSM electrical activities. These channels likely contribute to depolarizing the DSM cell membrane, leading to bladder overactivity. Our research focuses on understanding TRPM4 channel function in the DSM cells of mice, using computational modeling. We aimed to create a detailed computational model of the TRPM4 channel based on existing electrophysiological data. We employed a modified Hodgkin-Huxley model with an incorporated TRP-like current to simulate action potential firing in response to current and synaptic stimulus inputs. Validation against experimental data showed close agreement with our simulations. Our model is the first to analyze the TRPM4 channel's role in DSM electrical activity, potentially revealing insights into bladder overactivity. In conclusion, TRPM4 channels are pivotal in regulating human DSM function, and TRPM4 channel inhibitors could be promising targets for treating overactive bladder.

Human HPSE2 gene transfer ameliorates bladder pathophysiology in a mutant mouse model of urofacial syndrome.

Rare early-onset lower urinary tract disorders include defects of functional maturation of the bladder. Current treatments do not target the primary pathobiology of these diseases. Some have a monogenic basis, such as urofacial, or Ochoa, syndrome (UFS). Here, the bladder does not empty fully because of incomplete relaxation of its outflow tract, and subsequent urosepsis can cause kidney failure. UFS is associated with biallelic variants of HPSE2, encoding heparanase-2. This protein is detected in pelvic ganglia, autonomic relay stations that innervate the bladder and control voiding. Bladder outflow tracts of Hpse2 mutant mice display impaired neurogenic relaxation. We hypothesized that HPSE2 gene transfer soon after birth would ameliorate this defect and explored an adeno-associated viral (AAV) vector-based approach. AAV9/HPSE2, carrying human HPSE2 driven by CAG, was administered intravenously into neonatal mice. In the third postnatal week, transgene transduction and expression were sought, and ex vivo myography was undertaken to measure bladder function. In mice administered AAV9/HPSE2, the viral genome was detected in pelvic ganglia. Human HPSE2 was expressed and heparanase-2 became detectable in pelvic ganglia of treated mutant mice. On autopsy, wild-type mice had empty bladders, whereas bladders were uniformly distended in mutant mice, a defect ameliorated by AAV9/HPSE2 treatment. Therapeutically, AAV9/HPSE2 significantly ameliorated impaired neurogenic relaxation of Hpse2 mutant bladder outflow tracts. Impaired neurogenic contractility of mutant detrusor smooth muscle was also significantly improved. These results constitute first steps towards curing UFS, a clinically devastating genetic disease featuring a bladder autonomic neuropathy.

Evaluating the effectiveness of early urethral catheter removal combined with intermittent catheterization for promoting early recovery of bladder function after laparoscopic radical hysterectomy: a study protocol for a randomized controlled trial.

BACKGROUND: Bladder dysfunction, notably urinary retention, emerges as a significant complication for cervical cancer patients following radical hysterectomy, predominantly due to nerve damage, severely impacting their postoperative quality of life. The challenges to recovery include insufficient pelvic floor muscle training and the negative effects of prolonged postoperative indwelling urinary catheters. Intermittent catheterization represents the gold standard for neurogenic bladder management, facilitating bladder training, which is an important behavioral therapy aiming to enhance bladder function through the training of the external urethral sphincter and promoting the recovery of the micturition reflex. Nevertheless, gaps remain in current research regarding optimal timing for intermittent catheterization and the evaluation of subjective symptoms of bladder dysfunction. METHODS: Cervical cancer patients undergoing laparoscopic radical hysterectomy will be recruited to this randomized controlled trial. Participants will be randomly assigned to either early postoperative catheter removal combined with intermittent catheterization group or a control group receiving standard care with indwelling urinary catheters. All these patients will be followed for 3 months after surgery. The study's primary endpoint is the comparison of bladder function recovery rates (defined as achieving a Bladder Function Recovery Grade of II or higher) 2 weeks post-surgery. Secondary endpoints include the incidence of urinary tract infections, and changes in urodynamic parameters, and Mesure Du Handicap Urinaire scores within 1 month postoperatively. All analysis will adhere to the intention-to-treat principle. DISCUSSION: The findings from this trial are expected to refine clinical management strategies for enhancing postoperative recovery among cervical cancer patients undergoing radical hysterectomy. By providing robust evidence, this study aims to support patients and their families in informed decision-making regarding postoperative bladder management, potentially reducing the incidence of urinary complications and improving overall quality of life post-surgery. TRIAL REGISTRATION: ChiCTR2200064041, registered on 24th September, 2022.

Specialized pro-resolution mediators in the bladder: effects of resolvin E1 on diabetic bladder dysfunction in the type 1 diabetic male Akita mouse model.

BACKGROUND: One of the most common, but least studied, diabetic complication is diabetic bladder dysfunction. Current therapies include glucose control and symptom-based interventions. However, efficacy of these therapies is mixed and often have undesirable side effects. Diabetes is now known to be a chronic inflammatory disease. Specialized pro-resolving mediators are a class of compounds that promote the resolution of inflammation and have been shown to be effective in treating chronic inflammatory conditions. In this study we examine the ability of resolvin E1 to improve signs of diabetic bladder dysfunction. METHODS: Male Akita mice (Type 1 diabetic) develop hyperglycemia at 4 weeks and signs of bladder underactivity by 15 weeks. Starting at 15 weeks, mice were given one or two weeks of daily resolvin E1 and compared to age-matched wild type and untreated Akita mice. RESULTS: Resolvin E1 did not affect diabetic blood glucose after one week, although there was a slight decrease after two weeks. Diabetes decreased body weight and increased bladder weights and this was not affected by resolvin E1. Evan's blue dye extravasation (an indirect index of inflammation) was dramatically suppressed after one week of resolvin E1 treatment, but, surprisingly, had returned to diabetic levels after two weeks of treatment. Using cystometry, untreated Akita mice showed signs of underactivity (increased void volumes and intercontraction intervals). One week of resolvin E1treatment restored these cystometric findings back to control levels. After two weeks of treatment, cystometric changes were changed from controls but still significantly different from untreated levels, indicating a durable treatment effect even in the presence of increased inflammation at 2 weeks. CONCLUSIONS: Resolvin E1 has a beneficial effect on diabetic bladder dysfunction in the type 1 diabetic male Akita mouse model.

Pirfenidone improves voiding function by suppressing bladder fibrosis in underactive bladder rats.

Underactive bladder (UAB), characterized by a complex set of symptoms with few treatment options, can significantly reduce the quality of life of affected people. UAB is characterized by hyperplasia and fibrosis of the bladder wall as well as decreased bladder compliance. Pirfenidone is a powerful anti-fibrotic agent that inhibits the progression of fibrosis in people with idiopathic pulmonary fibrosis. In the current study, we evaluated the efficacy of pirfenidone in the treatment of bladder fibrosis in a UAB rat model. UAB was induced by crushing damage to nerve bundles in the major pelvic ganglion. Forty-two days after surgery, 1 mL distilled water containing pirfenidone (100, 300, or 500 mg/kg) was orally administered once every 2 days for a total of 10 times for 20 days to the rats in the pirfenidone-treated groups. Crushing damage to the nerve bundles caused voiding dysfunction, resulting in increased bladder weight and the level of fibrous related factors in the bladder, leading to UAB symptoms. Pirfenidone treatment improved urinary function, increased bladder weight and suppressed the expression of fibrosis factors. The results of this experiment suggest that pirfenidone can be used to ameliorate difficult-to-treat urological conditions such as bladder fibrosis. Therefore, pirfenidone treatment can be considered an option to improve voiding function in patient with incurable UAB.

Risk factors of video urodynamics and bladder management for long-term complications in patients with chronic spinal cord injury.

This study explores 15-year urological complications in chronic spinal cord injury (SCI) patients and investigates the predictive factors from video-urodynamic study (VUDS) and bladder management. Analyzing 864 SCI patients with a mean 15.6-year follow-up, we assessed complications and utilized multivariate logistic regression for risk evaluation. VUDS factors such as autonomic dysreflexia, detrusor sphincter dyssynergia, vesicourethral reflux (VUR), contracted bladder, and high voiding detrusor pressure significantly increased the likelihood of recurrent urinary tract infections (rUTI). Low bladder compliance, VUR, and contracted bladder notably raised the risk of hydronephrosis, while contracted bladder and detrusor overactivity with detrusor underactivity heightened chronic kidney disease risk. Volitional voiding reduced rUTI and VUR risk, whereas Valsalva maneuver-assisted voiding increased hydronephrosis risk. In conclusion, a contracted bladder identified in VUDS is associated with long-term urological complications in SCI, we propose that patients already experiencing a contracted bladder should prioritize volitional voiding as their preferred bladder management strategy to minimize the risk of additional complications such as rUTI and VUR. These findings unveil previously unexplored aspects in research, emphasizing the need for proactive management strategies in this patient population.

Cytokines in Bladder Pain Syndrome: A Review of the Literature.

INTRODUCTION AND HYPOTHESIS: Bladder pain syndrome (BPS) is poorly understood with both the aetiology and pathophysiology being unknown. Symptoms overlap with other disorders, such as overactive bladder (OAB) and chronic pelvic pain disorders such as endometriosis, making a consensus on how to diagnosis and manage patients challenging. The development of biomarkers for BPS may be the key to understanding more about its pathophysiology, as well as aiding diagnosis, subclassification, and discovering new drug targets for its management. As inflammation is widely understood to hold a central role in BPS, the evaluation of cytokines has gained interest. This article summarises the current literature and understanding of urinary, serum, and bladder tissue cytokines found elevated in patients with bladder pain syndrome. METHODS: literature search using Pub Med with the keywords "bladder pain syndrome", "painful bladder syndrome", "bladder pain", "Interstitial cystitis" AND "cytokines" or "inflammation". This study was except from institutional approval. RESULTS: Thirty-six cytokines have been identified as being statistically significantly elevated in either the serum, urine, or bladder tissue of patients with bladder pain syndrome in the 22 studies identified in this review of the literature. These cytokines include those from the interleukin group (n = 14), the CXC chemokine group (n = 5), and the C-C chemokine group (n = 7). CONCLUSIONS: CXCL-1, CXCL-8, CXCL-9, CXCL-10, CXCL-11 from the CXC chemokine group, and CCL2, CCL4, CCL5, CCL7, and CCL11 from the C-C chemokine group have been found to be significantly elevated in patients with bladder pain in the literature. Many of these analytes also have supporting evidence for their roles in bladder pain from animal models and studies in other chronic inflammatory conditions. It is likely that a single cytokine will not serve as an adequate biomarker of disease in bladder pain syndrome for either diagnosis or disease severity. Instead, panels of inflammatory mediators may reveal more about the different pathways of inflammation leading to similar presentations of bladder pain in patients.

Time-dependent progress of lower urinary tract dysfunction in streptozotocin-induced diabetic rats with or without low-dose insulin treatment.

Objectives: To examine time-dependent functional and structural changes of the lower urinary tract in streptozotocin-induced diabetic rats with or without low-dose insulin treatment and explore the pathophysiological characteristics of insulin therapy on lower urinary tract dysfunction (LUTD) caused by diabetes mellitus (DM). Methods: Female Sprague-Dawley rats were divided into five groups: normal control (NC) group, 4 weeks insulin-treated DM (4-DI) group, 4 weeks DM (4-DM) group, 8 weeks insulin-treated DM (8-DI) group and 8 weeks DM (8-DM) group. DM was initially induced by i.p. injection of streptozotocin (65 mg/kg), and then the DI groups received subcutaneous implantation of insulin pellets under the mid dorsal skin. Voiding behavior was evaluated in metabolic cages. The function of bladder and urethra in vivo were evaluated by simultaneous recordings of the cystometrogram and urethral perfusion pressure (UPP) under urethane anesthesia. The function of bladder and urethra in vitro were tested by organ bath techniques. The morphologic changes of the bladder and urethra were investigated using Hematoxylin-Eosin and Masson's staining. Results: Both 4-and 8-weeks diabetic rats have altered micturition patterns, including increased 12-h urine volume, urinary frequency/12 hours and voided volume. In-vivo urodynamics showed the EUS bursting activity duration is longer in 4-DM group and shorter in 8-DM group compared to NC group. UPP change in 8-DM were significantly lower than NC group. While none of these changes were found between DI and NC groups. Organ bath showed the response to Carbachol and EFS in bladder smooth muscle per tissue weights was decreased significantly in 4- and 8-weeks DM groups compared with insulin-treated DM or NC groups. In contrast, the contraction of urethral muscle and maximum urethral muscle contraction per gram of the tissue to EFS stimulation were significantly increased in 4- and 8-weeks DM groups. The thickness of bladder smooth muscle was time-dependently increased, but the thickness of the urethral muscle had no difference. Conclusions: DM-induced LUTD is characterized by time-dependent functional and structural remodeling in the bladder and urethra, which shows the hypertrophy of the bladder smooth muscle, reduced urethral smooth muscle relaxation and EUS dysfunction. Low-dose insulin can protect against diuresis-induced bladder over-distention, preserve urethral relaxation and protect EUS bursting activity, which would be helpful to study the slow-onset, time-dependent progress of DM-induced LUTD.

Long-term urodynamic findings following colo-, gastro- and ileocystoplasty.

PURPOSE: To evaluate the urodynamic changes in patients who have undergone colocystoplasty (CCP), gastrocystoplasty (GCP) and ileocystoplasty (ICP) in a retrospective study. Changes in urinary continence, incidence of pathologic contractions before and after augmentation, alterations of urodynamic parameters were also examined. METHODS: Eighty-four patients were included in the study who underwent bladder augmentation between 1987 and 2017. Group I: 35 patients with CCP. Group II: 18 patients with GCP. Group III: 31 patients with ICP. Cystometry was performed at 3, 6, and every 12 months, then biannually after augmentation. Pre- and postoperative urodynamic changes were analysed statistically. RESULTS: In Group I, two patients and in Group III, one patient remained incontinent after CCP and ICP. Bladder capacity increased significantly, maximal intra-vesical pressure decreased and compliance improved in all groups (p < 0.001). Postoperative studies showed pathologic contractions in the augmented bladder in half of the patients with GCP, in 43% of patients after CCP and 26% of patients with ICP. CONCLUSION: From the urodynamic point of view, ileum is the most adequate option in the long term. Contractions after augmentation might be caused by the remaining peristalsis of the detubularised segment. Further investigations are needed to evaluate pathologic contractions that remained after detubularisation.

Low-Intensity Extracorporeal Shock Wave Therapy Ameliorates Detrusor Hyperactivity with Impaired Contractility via Transient Potential Vanilloid Channels: A Rat Model for Ovarian Hormone Deficiency.

This study explores low-intensity extracorporeal shock wave therapy (LiESWT)'s efficacy in alleviating detrusor hyperactivity with impaired contractility (DHIC) induced by ovarian hormone deficiency (OHD) in ovariectomized rats. The rats were categorized into the following four groups: sham group; OVX group, subjected to bilateral ovariectomy (OVX) for 12 months to induce OHD; OVX + SW4 group, underwent OHD for 12 months followed by 4 weeks of weekly LiESWT; and OVX + SW8 group, underwent OHD for 12 months followed by 8 weeks of weekly LiESWT. Cystometrogram studies and voiding behavior tracing were used to identify the symptoms of DHIC. Muscle strip contractility was evaluated through electrical-field, carbachol, ATP, and KCl stimulations. Western blot and immunofluorescence analyses were performed to assess the expressions of various markers related to bladder dysfunction. The OVX rats exhibited significant bladder deterioration and overactivity, alleviated by LiESWT. LiESWT modified transient receptor potential vanilloid (TRPV) channel expression, regulating calcium concentration and enhancing bladder capacity. It also elevated endoplasmic reticulum (ER) stress proteins, influencing ER-related Ca2+ channels and receptors to modulate detrusor muscle contractility. OHD after 12 months led to neuronal degeneration and reduced TRPV1 and TRPV4 channel activation. LiESWT demonstrated potential in enhancing angiogenic remodeling, neurogenesis, and receptor response, ameliorating DHIC via TRPV channels and cellular signaling in the OHD-induced DHIC rat model.

Identifying Bladder Phenotypes After Spinal Cord Injury With Unsupervised Machine Learning: A New Way to Examine Urinary Symptoms and Quality of Life.

PURPOSE: Patients with spinal cord injuries (SCIs) experience variable urinary symptoms and quality of life (QOL). Our objective was to use machine learning to identify bladder-relevant phenotypes after SCI and assess their association with urinary symptoms and QOL. MATERIALS AND METHODS: We used data from the Neurogenic Bladder Research Group SCI registry. Baseline variables that were previously shown to be associated with bladder symptoms/QOL were included in the machine learning environment. An unsupervised consensus clustering approach (k-prototypes) was used to identify 4 patient clusters. After qualitative review of the clusters, 2 outcomes of interest were assessed: the total Neurogenic Bladder Symptom Score (NBSS) and the NBSS-satisfaction question (QOL). The NBSS and NBSS-satisfaction question at baseline and after 1 year were compared between clusters using analysis of variance and linear regression. RESULTS: Among the 1263 included participants, the 4 identified clusters were termed "female predominant," "high function, low SCI complication," "quadriplegia with bowel/bladder morbidity," and "older, high SCI complication." Using outcome data from baseline, significant differences were observed in the NBSS score, with the female predominant group exhibiting worse bladder symptoms. After 1 year, the overall bladder symptoms (NBSS Total) did not change significantly by cluster; however, the QOL score for the high function, low SCI complication group had more improvement (ß = -0.12, P = .005), while the female predominant group had more deterioration (ß = 0.09, P = .047). CONCLUSIONS: This study demonstrates the utility of machine learning in uncovering bladder-relevant phenotypes among SCI patients. Future research should explore cluster-based targeted strategies to enhance bladder-related outcomes and QOL in SCI.

Novel pharmacotherapeutic avenues for bladder storage dysfunction in men.

INTRODUCTION: Bladder storage dysfunction is associated with low quality of life in men and remains a challenging field in pharmacotherapy because of low persistence followed by patient-perceived lack of efficacy and adverse effects. The persistent desire for the development of novel pharmacotherapy is evident, leading to numerous research efforts based on its pathophysiology. AREAS COVERED: This review describes the pathophysiology, current pharmacotherapeutic strategies, and emerging novel drugs for male bladder storage dysfunction. The section on emerging pharmacotherapy provides an overview of current research, focusing on high-potential target molecules, particularly those being evaluated in ongoing clinical trials. EXPERT OPINION: As pharmacotherapies targeting alpha-adrenergic, beta-adrenergic, and muscarinic receptors - the current primary targets for treating male bladder storage dysfunction - have demonstrated insufficient efficacy and side effects, researchers are exploring various alternative molecular targets. Numerous targets have been identified as central to regulating bladder afferent nerve activity, and their pharmacological effects and potential have been evaluated in animal-based experiments. However, there is a limited number of clinical trials for these new pharmacotherapies, and they have not demonstrated clear superiority over current treatments. Further research is needed to develop new effective pharmacotherapies for bladder storage dysfunction in men.

Long-term follow-up of TREK-1 KO mice reveals the development of bladder hypertrophy and impaired bladder smooth muscle contractility with age.

Stretch-activated two-pore domain K+ (K2P) channels play important roles in many visceral organs, including the urinary bladder. The TWIK-related K+ channel TREK-1 is the predominantly expressed K2P channel in the urinary bladder of humans and rodents. Downregulation of TREK-1 channels was observed in the urinary bladder of patients with detrusor overactivity, suggesting their involvement in the pathogenesis of voiding dysfunction. This study aimed to characterize the long-term effects of TREK-1 on bladder function with global and smooth muscle-specific TREK-1 knockout (KO) mice. Bladder morphology, bladder smooth muscle (BSM) contractility, and voiding patterns were evaluated up to 12 mo of age. Both sexes were included in this study to probe the potential sex differences. Smooth muscle-specific TREK-1 KO mice were used to distinguish the effects of TREK-1 downregulation in BSM from the neural pathways involved in the control of bladder contraction and relaxation. TREK-1 KO mice developed enlarged urinary bladders (by 60.0% for males and by 45.1% for females at 6 mo; P < 0.001 compared with the age-matched control group) and had a significantly increased bladder capacity (by 137.7% at 12 mo; P < 0.0001) and compliance (by 73.4% at 12 mo; P < 0.0001). Bladder strips isolated from TREK-1 KO mice exhibited decreased contractility (peak force after KCl at 6 mo was 1.6 ± 0.7 N/g compared with 3.4 ± 2.0 N/g in the control group; P = 0.0005). The lack of TREK-1 channels exclusively in BSM did not replicate the bladder phenotype observed in TREK-1 KO mice, suggesting a strong neurogenic origin of TREK-1-related bladder dysfunction.NEW & NOTEWORTHY This study compared voiding function and bladder phenotypes in global and smooth muscle-specific TREK-1 KO mice. We found significant age-related changes in bladder contractility, suggesting that the lack of TREK-1 channel activity might contribute to age-related changes in bladder smooth muscle physiology.

Female Type 1 Diabetic Akita Mice Demonstrate Increased Bladder Contractility via FP Receptor Activation due to NLRP3-Mediated Inflammation.

BACKGROUND: Diabetic bladder dysfunction (DBD) is driven in part by inflammation which dysregulates prostaglandin release in the bladder. Precise inflammatory mechanisms responsible for such dysregulation have been elusive. Since prostaglandins impact bladder contractility, elucidating these mechanisms may yield potential therapeutic targets for DBD. In female Type 1 diabetic Akita mice, inflammation mediated by the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome is responsible for DBD. Here, we utilized female Akita mice crossbred with NLRP3 knock-out mice to determine how NLRP3-driven inflammation impacts prostaglandin release within the bladder and prostaglandin-mediated bladder contractions. METHODS: Akita mice were crossbred with NLRP3-⁣/- mice to yield four groups of non-diabetics and diabetics with and without the NLRP3 gene. Females were aged to 30 weeks when Akitas typically exhibit DBD. Urothelia and detrusors were stretched ex vivo to release prostaglandins. Prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) were quantified using enzyme linked immunosorbent assays (ELISA). In separate samples, ex vivo contractile force to PGE2 and PGF2α +/- the prostaglandin F (FP) receptor antagonist, AL8810, was measured. FP receptor protein expression was determined via western blotting. RESULTS: Stretch-induced PGE2 release increases in urothelia but decreases in detrusors of diabetics. However, PGE2-mediated bladder contractions are not impacted. Conversely, diabetics show no changes in PGF2α release, but PGF2α-mediated contractions increase significantly. This is likely due to signaling through the FP receptors as FP receptor antagonism prevents this increase and diabetics demonstrate a four-fold increase in FP receptor proteins. Without NLRP3-mediated inflammation, changes in prostaglandin release, contractility, and receptor expression do not occur. CONCLUSION: NLRP3-dependent inflammation dysregulates prostaglandin release and prostaglandin-mediated bladder contractions in diabetic female Akita mice via FP receptor upregulation.

Functional mapping of the lower urinary tract by epidural electrical stimulation of the spinal cord in decerebrated cat model.

Several neurologic diseases including spinal cord injury, Parkinson's disease or multiple sclerosis are accompanied by disturbances of the lower urinary tract functions. Clinical data indicates that chronic spinal cord stimulation can improve not only motor function but also ability to store urine and control micturition. Decoding the spinal mechanisms that regulate the functioning of detrusor (Detr) and external urethral sphincter (EUS) muscles is essential for effective neuromodulation therapy in patients with disturbances of micturition. In the present work we performed a mapping of Detr and EUS activity by applying epidural electrical stimulation (EES) at different levels of the spinal cord in decerebrated cat model. The study was performed in 5 adult male cats, evoked potentials were generated by EES aiming to recruit various spinal pathways responsible for LUT and hindlimbs control. Recruitment of Detr occurred mainly with stimulation of the lower thoracic and upper lumbar spinal cord (T13-L1 spinal segments). Responses in the EUS, in general, occurred with stimulation of all the studied sites of the spinal cord, however, a pronounced specificity was noted for the lower lumbar/upper sacral sections (L7-S1 spinal segments). These features were confirmed by comparing the normalized values of the slope angles used to approximate the recruitment curve data by the linear regression method. Thus, these findings are in accordance with our previous data obtained in rats and could be used for development of novel site-specific neuromodulation therapeutic approaches.

Bladder height to width ratio as a surrogate marker for non-physiological storage pressures in children with spinal dysraphism.

INTRODUCTION: Spinal dysraphism is the most frequent cause of neurogenic bladder. Urodynamic study (UDS) is an important component of the follow-up of a child with neurogenic bladder. However, it suffers from a lack of widespread availability and is further hampered by technical difficulties and difficulty in its interpretation in children. A neurogenic bladder often appears vertically elongated; only limited and sparse literature is available regarding objectively defining the bladder shape and the urodynamic parameters in the cohort. OBJECTIVES: This study aimed to investigate the usefulness of the bladder's height-to-width ratio (HWR) on cystogram as a screening tool for identifying "non-physiological" bladder pressures in children with spinal dysraphism. A prospective study was undertaken to evaluate children operated for spinal dysraphism. Cystogram, ultrasonography and UDS evaluation were performed. HWR was calculated by the ratio of the maximum height to the maximum bladder width at maximum cystometric capacity (MCC), where MCC was calculated using standard Koff's formula, given by (age in years + 2) *30 ml in children more than one year and weight *7 ml for infants. The children were categorised into groups based on maximum detrusor pressure (MDP) into two groups (MDP ≥ 30 cmH2O and MDP < 30 cmH2O). A receiver-operative characteristic curve was constructed to analyse the sensitivity and specificity of HWR in predicting the MDP. RESULTS: A total of 53 children, operated for spinal dysraphism, met the study criteria during the study period, from March 2021 to September 2022. The median age of children was 4 years (IQR-3-5.5 years). The HWR ratio was compared between the two groups and was significantly higher for the non-physiological pressure bladders than for physiological pressure bladders (mean of 1.55 vs 1.26, p = 0.001). On evaluating the sensitivity and specificity of HWR for discerning children with non-physiological bladder pressures were 87.5% and 48.28%, respectively. The area under the curve (AUC) was 0.781, with a cut-off value of 1.3. DISCUSSION: We attempted to evaluate the HWR based on bladder shape objectively. We demonstrated a moderate correlation between the bladder shape and the bladder pressures. An HWR of 1.3 or higher could be significant for identifying a non-physiological bladder storage pressure. CONCLUSION: The height to width ratio of the bladder on cystogram is a useful tool as a surrogate marker for non-physiological storage pressures in bladders of children with spinal dysraphism.

Maximal detrusor pressure can be predicted using technetium-99m-mertcaptoacetyltriglycine renal scintigraphy in the early stages of spinal cord injury.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the potential of technetium-99m-mercaptoacetyltriglycine (99mTc-MAG-3) renal scintigraphy for predicting maximal detrusor pressure in the early stages of spinal cord injury (SCI). SETTING: Tertiary rehabilitation facility. METHODS: Medical records of individuals with SCI admitted between January 2020 and April 2023 who underwent both 99mTc-MAG-3 renal scintigraphy and urodynamic study within 90 days of SCI onset were retrospectively reviewed. Pearson's coefficient analysis was performed to determine the relationship between 99mTc-MAG-3 renal scintigraphy findings and urodynamic study findings. A multivariate linear regression analysis was performed to determine the best predictors of maximal detrusor pressure. A multivariate logistic regression analysis was performed to determine risk factors for high detrusor pressure. RESULTS: Ninety-four participants were enrolled in this study. Pearson's correlation analysis showed that effective renal plasma flow (ERPF) and ERPF (% predicted) were significantly correlated with maximal detrusor pressure. The multivariate linear regression analysis demonstrated that ERPF (% predicted) was a significant predictor of maximal detrusor pressure. The multivariate logistic regression analysis showed that ERPF (% predicted) was significantly associated with high detrusor pressure. The receiver operating characteristic curve demonstrated that the predictive model had an area under the curve of 0.725, with an ERPF (% predicted) cut-off of 64.05%, sensitivity 1.000, and specificity 0.429. CONCLUSIONS: These results suggest that 99mTc-MAG-3 renal scintigraphy may be useful for predicting high detrusor pressure in early SCI and may guide the timing of urodynamic studies in individuals with early SCI for appropriate management of neurogenic lower urinary tract dysfunction.

Improvement of lower urinary tract dysfunction by a monoacylglycerol lipase inhibitor in mice with spinal cord injury.

AIMS: Activation of the endocannabinoid system by monoacylglycerol lipase (MAGL) blockade may affect the lower urinary tract function. We investigated the effect of an MAGL inhibitor, MJN110, on neurogenic lower urinary tract dysfunction (LUTD) in the mouse model of spinal cord injury (SCI). METHODS: Female C57BL/6 mice that underwent spinal cord transection at T8-10 level were divided into three groups consisting of (1) vehicle-treated SCI mice, (2) 5 mg/kg, or (3) 10 mg/kg of MJN110-treated SCI mice. MJN110 and vehicle were administered intraperitoneally for 7 days from 4 weeks after spinal cord transection. We then conducted awake cystometrograms and compared urodynamic parameters between three groups. The expression of cannabinoid (CB) receptors, TRP receptors, and inflammatory cytokines in L6-S1 dorsal root ganglia (DRG) or the bladder mucosa were evaluated and compared among three groups. Changes in the level of serum 2-arachidonoylglycerol (2-AG) and bladder MAGL were also evaluated. RESULTS: In the cystometrogram, detrusor overactivity (DO) parameters, such as the number of nonvoiding contraction (NVC), a ratio of time to the 1st NVC to intercontraction interval (ICI), and NVC integrals were improved by MJN110 treatment, and some effects were dose dependent. Although MJN110 did not improve voiding efficiency, it decreased bladder capacity, ICI, and residual urine volume compared to vehicle injection. MJN110 treatment groups had lower CB2, TRPV1, TRPA1, and inflammatory cytokines mRNA levels in DRG and bladder mucosa. Serum 2-AG was increased, and bladder MAGL was decreased after MAGL inhibitor treatment. CONCLUSIONS: MAGL inhibition improved LUTD including attenuation of DO after SCI. Thus, MAGL can be a therapeutic target for neurogenic LUTD after SCI.