Urethral Sensations are Related to the Development of Detrusor Overactivity

The pressure flow study investigation of pathophysiology of post-micturition dribble in male patients

PURPOSE

In this study, we aimed to elucidate the pathophysiology of post-micturition dribble (PMD) through analyzing several variables including pressure flow study (PFS) findings and symptoms questionnaire.

METHODS

We retrospectively analyzed male patients who visited our department between 2010 and 2020. We used modified international prostate symptom score (m-IPSS), which consists of eight sub-score related to lower urinary tract symptoms (Incomplete Emptying, Frequency, Intermittency, Urgency, Weak Stream, Straining, Nocturia, and PMD) and one question related to quality of life (QOL). Multivariate regression analysis was conducted to evaluate the relationship between PMD and the variables, including age, prostate volume (PV), body mass index, bladder outlet obstruction index (BOOI), bladder contractility index, and bladder voiding efficiency, which were obtained by PFS.

RESULTS

A total of 143 male patients were analyzed. The patients with PMD showed significantly larger PV and higher BOOI, and worse IPSS total and QOL score than those without PMD. Multivariate regression analysis showed that large PV and BOOI were significantly associated with PMD. In Spearman's correlation analysis, PMD and each m-IPSS sub-score except nocturia had significant positive correlation. Furthermore, Spearman's correlation analysis showed that PMD and QOL had significant strong positive correlation.

CONCLUSION

PMD was significantly associated with large PV and BOO evaluated by PFS. Furthermore, PMD significantly exacerbated QOL. The severity of PMD and the other m-IPSS sub-score except nocturia could have intercorrelation with each other.

Clinical features and urodynamic findings in elderly men with chronic prostatitis

OBJECTIVES

To investigate the complication rate of chronic prostatitis/chronic pelvic pain syndrome in men with lower urinary tract symptoms, and to clarify their clinical features and urodynamic findings.

METHODS

We retrospectively reviewed the clinical data of treatment-naïve men with lower urinary tract symptoms. Patients were divided into two groups (chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms and lower urinary tract symptoms only) according to the presence or absence of chronic prostatitis/chronic pelvic pain syndrome, and the patient characteristics as well as the parameters of lower urinary tract symptoms and lower urinary tract function assessed by urodynamics were compared. The diagnostic criteria for chronic prostatitis/chronic pelvic pain syndrome included a complaint of pelvic pain for ≥3 months, National Institutes of Health Chronic Prostatitis Symptom Index pain subscore ≥4, and negative culture of a urine specimen collected after prostate massage.

RESULTS

Out of 386 men, 123 (31.9%) had chronic prostatitis/chronic pelvic pain syndrome. Parameters of lower urinary tract symptoms and National Institutes of Health Chronic Prostatitis Symptom Index scores were significantly higher in the chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms group. Although there were no significant intergroup differences in voiding parameters such as maximum flow rate and bladder outlet obstruction index, storage functions such as the incidence of detrusor overactivity and bladder compliance were significantly reduced in the chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms group. The multivariable regression analysis revealed that a low serum total testosterone level (<3.5 ng/mL), complications of hyperlipidemia, and presence of overactive bladder and detrusor overactivity were significantly associated with the development of chronic prostatitis/chronic pelvic pain syndrome.

CONCLUSIONS

Chronic prostatitis causes a significant decrease in storage function, such as an increase in detrusor overactivity. Additionally, low serum testosterone levels and hyperlipidemia were found to be significantly associated with the development of chronic prostatitis/chronic pelvic pain syndrome in men with lower urinary tract symptoms.

Therapeutic effect of TAC-302, a cyclohexenoic fatty alcohol derivative, on bladder denervation-related storage and voiding dysfunctions in rats

AIMS

To evaluate the therapeutic effect of TAC-302, a cyclohexenoic fatty alcohol derivative, on bladder denervation-related storage and voiding dysfunctions in rats with bladder outlet obstruction (BOO).

METHODS

BOO was achieved by partial ligature of the proximal urethra in female rats. Two weeks later, BOO rats were divided into two groups and treated orally with vehicle or 10 mg/kg TAC-302 twice a day for 4 weeks. Urodynamic and immunohistochemical evaluation of the bladder muscle layer was performed. In another study, the BOO rats were treated with intravenous tamsulosin at cystometry. The detrusor contractility in each group was evaluated using the modified Shafer's nomogram.

RESULTS

Two weeks after BOO, the rats showed significant increases in non-voiding contraction (NVCs) and residual urine volume (RUV) compared to the sham group. Moreover, 6 weeks after BOO, BOO vehicle rats showed significant increases in NVCs and RUV and decreases in detrusor contractility and in the nerve fiber density in the urinary bladder compared to the sham group. BOO-induced denervation of the urinary bladder was partially improved by oral treatment with TAC-302. Oral treatment with TAC-302 significantly reduced the amplitude and frequency of NVCs (P < 0.05) and increased detrusor contractility and tended to reduce RUV compared with the BOO vehicle group. In contrast, the intravenous administration of tamsulosin significantly reduced the frequency of NVCs, but not RUV.

CONCLUSIONS

TAC-302 improved storage and voiding dysfunctions by improving bladder denervation and detrusor underactivity even when the treatment was started after storage and voiding dysfunctions had already occurred.

Possible role of hyposensitivity of C-fiber afferents at the proximal urethra in the development of urge urinary incontinence in patients with detrusor overactivity

OBJECTIVE

The aim of the present study was to investigate associations between urethral sensation and urge urinary incontinence (UUI) in patients with and without detrusor overactivity (DO).

METHODS

The medical records of 80 consecutive patients who underwent filling cystometry and urethral current perception threshold (CPT) tests were examined retrospectively. Following the exclusion of 4 patients not eligible for analysis, patients were classified into neurogenic DO, idiopathic DO, or DO-negative groups based on neurological and cystometric findings (n = 30, 12, and 34, respectively). Eleven DO-negative patients were defined as normal controls on cystometrograms (CMG) using the following exclusion criteria: bladder compliance <12.5 mL/cmH₂ O, volume >275 mL at first filling sensation, and comorbidities possibly affecting lower urinary tract function. Thus, 53 patients were finally included in the study. Proximal urethral CPT was evaluated with intraurethral square-wave stimulation at 3 Hz to activate C-fiber afferents.

RESULTS

Median CPT was higher in neurogenic and idiopathic DO than in the normal CMG group (11.3 and 9.0 vs. 2.8 mA, respectively; P < .05), as well as in patients with UUI (n = 19) compared with non-UUI patients (n = 34; 12.5 vs. 5.4 mA, respectively; P < .05). The proportion of UUI patients was significantly greater in the DO-positive groups than in the normal CMG group (P < .05). CPTs were not associated with bladder capacity at the first filling sensation (r = 0.11).

CONCLUSION

Hyposensitive C-fibers of the proximal urethra may contribute to the development of urodynamic DO as well as UUI in patients complaining of lower urinary tract symptoms.

Octodon degus, a new model to study the agonist and plexus-induced response in the urinary bladder

Urinary bladder function consists in the storage and controlled voiding of urine. Translational studies require animal models that match human characteristics, such as Octodon degus, a diurnal rodent. This study aims to characterize the contractility of the detrusor muscle and the morphology and code of the vesical plexus from O. degus. Body temperature was measured by an intra-abdominal sensor, the contractility of detrusor strips was evaluated by isometric tension recording, and the vesical plexus was studied by electrical field stimulation (EFS) and immunofluorescence. The animals showed a diurnal chronotype as judged from core temperature. The myogenic contractile response of the detrusor muscle to increasing doses of KCl reached its maximum (31.04 mN/mm²) at 60 mM. In the case of cumulative dose-response of bethanecol, the maximum response (37.42 mN/mm²) was reached at 3.2 × 10^-4 M. The response to ATP was clearly smaller (3.8 mN/mm²). The pharmacological dissection of the EFS-induced contraction identified ACh and sensory fibers as the main contributors to this response. The neurons of the vesical plexus were located mainly in the trigone area, grouped in big and small ganglia. Out of them, 48.1 % of the neurons were nitrergic and 62.7 % cholinergic. Our results show functional and morphological similarities between the urinary bladder of O. degus and that of humans.

Sex differences in the physiology and pharmacology of the lower urinary tract

Sexual dimorphism is not only noticed in the prevalence of many diseases, but also in multiple physiological functions in the body. This review has summarized findings from published literature on the sex differences of the pathophysiology and pharmacology of the lower urinary tract (LUT) of humans and animals. Sex differences have been found in several key areas of the LUT, such as overactive bladder, expression and function of neurotransmitter receptors in the bladder and urethra, and micturition patterns in humans and animals. It is anticipated that this review will not only evoke renewed interest for further research on the mechanism of sex differences in the pathophysiology of the LUT (especially for overactive bladder), but might also open up the possibilities for gender-based drug development by pharmaceutical industries in order to find separate cures for men and women with diseases of the LUT.