Comparison of the effects of serotonin selective,norepinephrine selective,and dual serotonin and norepinephrine reuptake inhibitors on lower urinary tract function in cats

Previous studies showed that the dual serotonin (5-hydroxytryptamine, 5-HT) and norepinephrine (NE) reuptake inhibitor, duloxetine, increases bladder capacity and urethral sphincter electromyographic (EMG) activity in a cat model of acetic acid-induced bladder irritation. The present study aimed to determine the relative importance of 5-HT versus NE reuptake inhibition for mediating these effects by examining drugs that are selective for either the 5-HT or NE system or both. Similar to duloxetine, venlafaxine (0.1 to 10 mg/kg), also a dual serotonin and norepinephrine reuptake inhibitor, produced marked increases in bladder capacity and EMG activity that were reversed by methiothepin (0.3 mg/kg). S-norfluoxetine (0.01 to 10 mg/kg), a serotonin selective reuptake inhibitor, produced small but significant increases in bladder capacity and EMG activity at doses of 3 and 10 mg/kg. Thionisoxetine (0.01 to 3.0 mg/kg), a NE selective reuptake inhibitor, produced no effects on bladder capacity or sphincter EMG activity. Surprisingly, co-administration of thionisoxetine and s-norfluoxetine up to doses of 1 mg/kg of each compound produced no effect on lower urinary tract function. These doses were the maximum that could be administered in combination due to drug-induced emergence of skeletal muscle activity in chloralose-anesthetized animals. These results indicate that there are unexplained pharmacological differences between the effects of single compounds that exhibit dual NE and 5-HT reuptake inhibition and a combination of compounds that exhibit selective NE and 5-HT reuptake inhibition on lower urinary tract function.     

Stem cell applications for pathologies of the urinary bladder

New stem cell based therapies are undergoing intense research and are widely investigated in clinical fields including the urinary system. The urinary bladder performs critical complex functions that rely on its highly coordinated anatomical composition and multiplex of regulatory mechanisms. Bladder pathologies resulting in severe dysfunction are common clinical encounter and often cause significant impairment of patient’s quality of life. Current surgical and medical interventions to correct urinary dysfunction or to replace an absent or defective bladder are sub-optimal and are associated with notable complications. As a result, stem cell based therapies for the urinary bladder are hoped to offer new venues that could make up for limitations of existing therapies. In this article, we review research efforts that describe the use of different types of stem cells in bladder reconstruction, urinary incontinence and retention disorders. In particular, stress urinary incontinence has been a popular target for stem cell based therapies in reported clinical trials. Furthermore, we discuss the relevance of the cancer stem cell hypothesis to the development of bladder cancer. A key subject that should not be overlooked is the safety and quality of stem cell based therapies introduced to human subjects either in a research or a clinical context.     

The effect of radiation therapy on post-prostatectomy urinary function

AimWe sought to evaluate the effect of radiation therapy on post-prostatectomy urinary quality of life in prostate cancer patients.BackgroundIn some men with non-metastatic prostate cancer, radiation therapy is indicated following prostatectomy. The radiation toxicity and quality of life considerations are unique in the post-prostatectomy setting.Materials and methodsA total of 106 patients receiving post-prostatectomy radiation therapy completed the Expanded Prostate Cancer Index Composite questionnaire before radiation and at 2-year follow-up. The primary outcomes of this study were the urinary domain summary score and subscale scores. Planned analysis was performed based on time interval from prostatectomy to radiation therapy.ResultsAmong the 106 patients analyzed, the mean urinary domain summary score worsened at 2-year follow-up after radiation therapy, lowering from 77.23–72.51 (p = 0.0085). Similar worsening was observed in the subscales of function (p = 0.003), bother (p = 0.0397), and incontinence (p = 0.0003). Urinary incontinence showed the greatest observable change among subscales. While the summary score worsened (p = 0.0031) among patients receiving radiation therapy more than 1 year after prostatectomy, it did not show statistically significant change in those treated 1 year or less after prostatectomy.ConclusionOur results demonstrate that post-prostatectomy radiation therapy is associated with modest declines in reportable urinary quality of life. Patients receiving radiation therapy more than 1 year after prostatectomy showed greater worsening of urinary quality of life, which indicates that there may be no functional advantage to delaying radiation therapy beyond the initial postoperative period.     

The impact of state of bladder fullness on tonic and phasic activation of the pelvic floor muscles in women

PurposeWe aimed to determine if state of bladder fullness affects pelvic floor muscle activation in healthy women without urogenital symptoms.Materials and methodsTwenty-three nulliparous, continent female participants were recruited to participate. Women were randomized to begin the protocol with either an empty (EF) or a full (FE) bladder. Tonic and maximal voluntary pelvic floor muscle electromyographic activity were measured in three states of bladder fullness (empty, full and uncomfortably full). Electromyographic signal amplitudes were compared among bladder states using separate two-way repeated-measures analyses of variance including bladder state and test order as main effects as well as the interaction between bladder state and test order.ResultsTonic activity of the pelvic floor muscles was significantly higher in the full and uncomfortably full bladder states compared to when the bladder was empty (p < 0.005). Maximum voluntary electromyographic activation was unaffected by state of bladder fullness (p = 0.713).ConclusionsConsistent with studies in which the bladder was filled through saline infusion, these results suggest that tonic activity of the PFMs is higher when the bladder is full compared to when it is empty. However once the bladder is moderately full, tonic PFM activity does not increase with increases in bladder volume.