Effects of duloxetine and WAY100635 on pudendal inhibition of bladder overactivity in cats

Relationship between Lower Urinary Tract Dysfunction and Clinical Features in Chinese Parkinson's Disease Patients

Background

Lower urinary tract (LUT) dysfunction is very common in Parkinson's disease (PD) patients. However, the number of studies conducted on LUT dysfunction and its related factors in Chinese PD patients is very limited, and there is no international consensus concerning the results.

Methods

This cross-sectional study enrolled 100 Chinese PD patients. The patients were classified based on their overactive bladder symptom score (OABSS) and then assigned to either a PD with overactive bladder (PD-OAB) group or a PD with no overactive bladder (PD-NOAB) group. A binary logistic regression analysis was performed to identify the accompanying factors for overactive bladder (OAB). Next, correlations between the OABSS and patient sex, age, age of onset, disease duration, MDS-UPDRS-III, H-Y stage, PD subtype, treatment, education, and nonmotor symptoms were analyzed to identify factors correlated with LUT dysfunction.

Results

Eighty nine (89%) of the PD patients suffered from LUT dysfunction, and OAB was diagnosed in 45 (45%) of those PD patients. The most common lower urinary tract (LUT) symptom in the PD patients was nighttime frequency (86%), followed by urgency (50%), urge incontinence (34%), and daytime frequency (17%). Patients in the PD-OAB group had an older age and age of onset, were at a more advanced Hoehn–Yahr stage, and had more severe motor symptoms and nonmotor symptoms, including worse cognition, and a greater incidence of REM sleep behavior disorder (RBD). A binary logistic regression analysis showed that a lower Frontal Assessment Battery (FAB) score, higher H-Y stage, and RBD accompanied with a higher prevalence of OAB in PD patients. A multiple linear regression analysis showed that the OABSS was significantly influenced by the FAB score, H-Y stage, RBD, and age.

Conclusions

The FAB score, H-Y stage, and RBD are accompanying factors for OAB. A higher OABSS in PD patients was related to a lower FAB score for frontal lobe executive dysfunction, a higher H-Y stage for severity of motor disorders, RBD, and an older age.

Transsynaptic tracing to dissect supraspinal serotonergic input regulating the bladder reflex in rats

AIMS

This study was designed to determine specific cell groups of the raphe nuclei (RN) that give rise to supraspinal serotonergic projections regulating the bladder reflex.

METHODS

Anesthetized rats underwent surgery to open the abdomen and expose the bladder. A total of 6 µL transsynaptic neuronal tracer pseudorabies virus (PRV-152), encoding for green fluorescent protein (GFP), was injected into the bladder detrusor. After 72 or 96 h, animals were perfused and the brain was dissected for processing transverse and sagittal sections. Subsequently, fluorescent immunohistochemistry for GFP and Serotonin (5-hydroxytryptamine [5-HT]) was performed in the brain sections. Under the microscope, each RN subset was characterized individually from caudal to rostral according to the atlas. GFP⁺ or GFP/5-HT double labeled neurons in each subset were quantified for statistical analysis.

RESULTS

At 72-h post-infection, very few GFP⁺ or GFP/5-HT double-labeled neurons appeared in the brainstem and beyond. In contrast, many labeled neurons were found at these levels after 96 h. Quantitative analysis showed that the majority of infected 5-HT⁺ neurons were located in the pallidus, obscurus, and magnus nuclei. Conversely, very few infected neurons were found in other raphe subsets, that is the pontis, median, dorsal, or linear nuclei. Overall, the raphe magnus had the highest number of GFP-labeled and GFP/5-HT double-labeled cells.

CONCLUSIONS

The caudal subsets of RN, especially the raphe magnus, are the main sources of serotonergic input to the lower spinal cord controlling bladder activity.

Combined Use of Duloxetine and Olanzapine in the Treatment of Urologic Chronic Pelvic Pain Syndromes Refractory to Conventional Treatment: A Case Report

Patients with urologic chronic pelvic pain syndromes (UCPPS) report interstitial cystitis/bladder pain syndrome and/or chronic prostatitis/chronic pelvic pain syndrome. The pathogenesis of these syndromes remains unclear and there is currently no standard treatment. UCPPS is, therefore, often misdiagnosed and its management is complex. The present case report involves a 62-year-old male patient with UCPPS whose main presentation is painful bladder filling and painful urgency refractory to conventional treatment with medication, which was successfully treated with the combined use of duloxetine and olanzapine. The combined use of duloxetine and olanzapine may become a new therapeutic option in the management of UCPPS.

Glutamatergic Mechanisms Involved in Bladder Overactivity and Pudendal Neuromodulation in Cats

The involvement of ionotropic glutamate receptors in bladder overactivity and pudendal neuromodulation was determined in α-chloralose anesthetized cats by intravenously administering MK801 (a NMDA receptor antagonist) or CP465022 (an AMPA receptor antagonist). Infusion of 0.5% acetic acid (AA) into the bladder produced bladder overactivity. In the first group of 5 cats, bladder capacity was significantly (P < 0.05) reduced to 55.3±10.0% of saline control by AA irritation. Pudendal nerve stimulation (PNS) significantly (P < 0.05) increased bladder capacity to 106.8 ± 15.0% and 106.7 ± 13.3% of saline control at 2T and 4T intensity, respectively. T is threshold intensity for inducing anal twitching. MK801 at 0.3 mg/kg prevented the increase in capacity by 2T or 4T PNS. In the second group of 5 cats, bladder capacity was significantly (P < 0.05) reduced to 49.0 ± 7.5% of saline control by AA irritation. It was then significantly (P < 0.05) increased to 80.8±13.5% and 79.0±14.0% of saline control by 2T and 4T PNS, respectively. CP465022 at 0.03-1 mg/kg prevented the increase in capacity by 2T PNS and at 0.3-1 mg/kg prevented the increase in capacity by 4T PNS. In both groups, MK801 at 0.3 mg/kg and CP465022 at 1 mg/kg significantly (P < 0.05) increased the prestimulation bladder capacity (about 80% and 20%, respectively) and reduced the amplitude of bladder contractions (about 30 and 20 cmH₂O, respectively). These results indicate that NMDA and AMPA glutamate receptors are important for PNS to inhibit bladder overactivity and that tonic activation of these receptors also contributes to the bladder overactivity induced by AA irritation.

Screening and Optimization of Nerve Targets and Parameters Reveals Inhibitory Effect of Pudendal Stimulation on Rat Bladder Hypersensitivity

BACKGROUND AND OBJECTIVES

Neuromodulation has been reported to reliably improve symptoms of bladder overactivity and sometimes pain. The effect of electrical stimulation of several nerve pathways demonstrated to alter cystometric responses to bladder distension was examined on nociceptive responses in models of bladder hypersensitivity.

METHODS

Bladder hypersensitivity was produced by several published methods including neonatal inflammation, acute inflammation, and chronic stress. Effects of different sites of stimulation (L6 and T13 nerve roots, proximal and distal pudendal nerves [PNs]) on nociceptive reflex responses to urinary bladder distension in urethane-anesthetized female rats were assessed and a parametric analysis of parameters of stimulation was performed.

RESULTS

Bilateral biphasic stimulation of the proximal PNs resulted in statistically significant inhibition of visceromotor and cardiovascular responses to bladder distension in rats made hypersensitive by neonatal bladder inflammation. We found a range of optimal stimulation frequencies (5-10 Hz) which produced robust inhibitory effects when using short pulse widths (100-240 μs). Onset of inhibition was within minutes and persisted for several minutes after the stimulus was discontinued. Use of bilateral PN stimulation in acute inflammation and stress-induced hypersensitivity models as well as unilateral stimulation, very distal PN cutaneous branch stimulation, and stimulation of the T13 and L6 nerve roots all proved ineffective with the parameters used.

CONCLUSIONS

This study suggests that inhibitory effects of bilateral PN stimulation can be evoked in a rodent hypersensitivity model at relatively low frequencies with short pulse widths. The onset of effect is rapid, which suggests the potential for treating episodic pain in painful bladder disorders.

Pioneering drugs for overactive bladder and detrusor overactivity: Ongoing research and future directions

The ongoing research on pioneering drug candidates for the overactive bladder (OAB) aimed to overcome the limitations of currently licensed pharmacotherapies, such as antimuscarinics, β3-adrenergic agents, and botulinum neurotoxin, has been reviewed performing a systematic literature review and web search. The review covers the exploratory agents alternative to available medications for OAB and that may ultimately prove to be therapeutically useful in the future management of OAB patients based on preclinical and early clinical data. It emerges that many alternative pharmacological strategies have been discovered or are under investigation in disease-oriented studies. Several potential therapeutics are known for years but still find obstacles to pass the clinical stages of development, while other completely novel compounds, targeting new pharmacological targets, have been recently discovered and show potential to translate into clinical therapeutic agents for idiopathic and neurogenic OAB syndrome. The global scenario of investigational drugs for OAB gives promise for the development of innovative therapeutics that may ultimately prove effective as first, combined or second-line treatments within a realistic timescale of ten years.

Impact of Bioelectronic Medicine on the Neural Regulation of Pelvic Visceral Function

Neuromodulation elicited by electrical stimulation of peripheral or spinal nerves is a U.S. Food and Drug Administered (FDA)-approved therapy for treating disorders of the pelvic viscera, including urinary urgency, urgency-frequency, nonobstructive urinary retention and fecal incontinence. The technique is also being tested experimentally for its efficacy in treating interstitial cystitis, chronic constipation and pelvic pain. The goal of neuromodulation is to suppress abnormal visceral sensations and involuntary reflexes and restore voluntary control. Although detailed mechanisms underlying the effects of neuromodulation are still to be elucidated, it is generally believed that effects are due to stimulation of action potentials in somatic afferent nerves. Afferent nerves project to the lumbosacral spinal cord, where they release excitatory neurotransmitters that activate ascending pathways to the brain or spinal circuits that modulate visceral sensory and involuntary motor mechanisms. Studies in animals revealed that different types of neuromodulation (for example, stimulation of a sacral spinal root, pudendal nerve or posterior tibial nerve) act by releasing different inhibitory and excitatory neurotransmitters in the central nervous system. In addition, certain types of neuromodulation inhibit visceral smooth muscle by initiating reflex firing in peripheral autonomic nerves or excite striated sphincter muscles by initiating reflex firing in somatic efferent nerves. This report will provide a brief summary of (a) neural control of the lower urinary tract and distal bowel, (b) clinical use of neuromodulation in the treatment of bladder and bowel dysfunctions,

Innovative pharmacotherapies for women with overactive bladder: where are we now and what is in the pipeline?

INTRODUCTION AND HYPOTHESIS

The impressive prevalence of overactive bladder (OAB) and the relevant limitations of current treatments urge the need for novel therapeutic approaches.

METHODS

A systematic literature and web search was performed to identify investigational drugs that entered the early and late phases of clinical development for women with OAB symptoms.

RESULTS

Approved pharmacological therapies for OAB (antimuscarinics, beta-3 agonists, and botulinum toxin) are evolving with the development of alternative administration methods, combination strategies, and novel compounds, expected to improve effectiveness, bladder selectivity, and dose flexibility. A wealth of investigational compounds, developed with both public and companies' indoor nonclinical disease-oriented studies, entered the early and late stages of clinical development in the last decade. Most non-anticholinergic compounds in ongoing clinical trials target central and peripheral neurotransmitter receptors involved in neurological modulation of micturition, nonadrenergic-noncholinergic mechanisms, cyclic nucleotide metabolism, different subtypes of ion channels or peripheral receptors of prostaglandins, vanilloids, vitamin D3, and opioids. Fascinating advances are ongoing also in the field of genetic therapy.

CONCLUSIONS

New pharmaceutical formulations and drug combinations are expected to be available in the next decade in order to overcome the limitations of current drugs for OAB. Although proof-of-concept, patient-oriented studies yielded disappointing results for several tentative drugs, a lot of clinical research is ongoing that is expected to provide clinicians with novel therapeutic agents in the near future.