External urethral sphincter activity in diabetic rats

Relationship between pelvic floor muscle function and insulin resistance among non-diabetic females: a 3d ultrasound evaluation

BACKGROUND

To use the three-dimensional (3D) ultrasound for assessment of pelvic floor muscle function in non-diabetic females with insulin resistance (IR), and to evaluate its functional relationship with insulin levels.

METHODS

From October 2022 to November 2023, 216 non-diabetic females with insulin-resistant (IR group) and 118 normal females (control group) were sequentially recruited from our hospital for our study. The 3D ultrasound was used to assess the levator hiatus in resting state for all females regarding diameter lines, perimeters and areas; as well as the Valsalva manoeuvre (VM). The t-test and linear regression model were used to analyse the collected data.

RESULTS

The analysis indicates that there were significant differences in the resting state of the levator hiatus between the IR and the control groups (14.8 ± 5.8 cm2 and 11.6 ± 2.7 cm2, p < 0.05); and in the VM (18.2 ± 6.3 cm2 and 13.4 ± 3. 4 cm2, p < 0.05). In addition, the anterior-posterior (AP) diameters of the hiatus on VM were significantly increased in the IR group (40.0 ± 4.7 mm and 33.0 ± 4.4 mm, p < 0.05). With insulin levels as the dependent variable, multivariate regression analysis shows that insulin levels were significantly correlated with the levator hiatus area on VM (p < 0.05) and waist circumference (p < 0.05). The pelvic organ descent on VM in the IR group was significant (p < 0.05).

CONCLUSIONS

The areas of resting state levator hiatus and on VM were significantly larger in the IR than that in the control groups. In addition, the position of the pelvic organ on VM in the IR group was significantly descended. The insulin levels were correlated with the pelvic floor muscle function.

Risk factors for postpartum urinary incontinence: The impact of early-onset and late-onset Gestational Diabetes Mellitus in a nested case-control study

BACKGROUND

Gestational Diabetes Mellitus (GDM) and many other clinical variables have been associated with postpartum urinary incontinence (UI). However, the data are still restricted, and no study explored early- or late-onset GDM as a risk factor for this condition. We aimed to identify independent risk factors for postpartum UI, focusing on GDM and its early or late onset.

METHODS

A nested case control derived from the Diamater cohort study included 517 pregnant women who submitted to a planned C-section and followed by 6-18 months after delivery according to the timing of GDM diagnosis: early-onset GDM (before 20 weeks) and late-onset GDM(24-28 weeks) and the occurrence of UI.

RESULTS

Univariate analysis showed that the risk for 6-18 months postpartum UI was 49% higher in non-Caucasian ethnicity (1.49,1.02-2.18), 3,3 times higher in previous bariatric surgery [3.37,1.36-8.21], 39% higher in GDM women (1.39,1.01-1.93), and 5% higher for each BMI score in prepregnancy (1.05, 1.03-1.08) and at the end of pregnancy (1.05,1.02-1.08). Multivariate logistic regression analysis indicates that prepregnancy BMI was the only independent factor associated with the 6-18 months postpartum UI (adj 1.05, 95 %CI 1.02-1.08, P <.001). After stratifying, a second univariate and multivariate analysis were done according to the prepregnancy BMI cutoff score of 25. Thus, a significant association between GDM and postpartum UI in prepregnancy overweight women (RR: 1.91; 95 %CI 1.25-2.90, P =.003) and no association between GDM and 6-18 months postpartum UI in normal prepregnancy BMI (RR: 0.78, 95 %CI 0.39-1.54, P =.482) were found. After multivariate regression, the early-onset-GDM remained the unique independent adjusted risk factor for 6-18 months postpartum UI analysis (adjRR 2.15, 95 %CI 1.33-3.46, P =.002).

CONCLUSION

After a planned C-section, we observed a 6-18 months postpartum UI higher occurrence after GDM, either in early-onset GDM or late-onset GDM. In addition, being overweight (BMI > 25) among women with early-onset GDM was associated with postpartum UI.

Potential role of oxidative stress in the pathogenesis of diabetic bladder dysfunction

Diabetes mellitus is a chronic metabolic disease, posing a considerable threat to global public health. Treating systemic comorbidities has been one of the greatest clinical challenges in the management of diabetes. Diabetic bladder dysfunction, characterized by detrusor overactivity during the early stage of the disease and detrusor underactivity during the late stage, is a common urological complication of diabetes. Oxidative stress is thought to trigger hyperglycaemia-dependent tissue damage in multiple organs; thus, a growing body of literature has suggested a possible link between functional changes in urothelium, muscle and the corresponding innervations. Improved understanding of the mechanisms of oxidative stress could lead to the development of novel therapeutics to restore the redox equilibrium and scavenge excessive free radicals to normalize bladder function in patients with diabetes.

Pelvic floor muscle strength in women with diabetes

Introduction and Aim: Diabetes mellitus (DM) is a global health problem with increasing prevalence linked to the alterations in the lifestyle, growing obesity rates and ageing. Women with insulin resistance (IR)/high insulin levels have worse electromyographic activity in the PFMs than women without IR/high insulin levels which prove the effect of IR/high insulin levels on PFMs. This study aimed at assessing and strengthening the pelvic floor muscles in women with diabetes and urinary incontinence.   Materials and Methods: The subjects were diabetic women of age group 45-55 with urinary incontinence assigned to one of two groups namely the group A (experimental group) and the group B (control group) which consisted of 30 patients each. The strength of the pelvic floor muscle was measured by vaginal examination prior and after the treatment and a Kegels Perineometer was inserted to measure the Strength of contraction (MOS), Length of hold (s), Repetitions (n) and Fast contractions (n) for both the groups. Experimental group was advised to do pelvic floor strengthening exercises in various positions with differing durations and increasing repetitions while control group received the regular physiotherapy care.   Results: The results revealed that there was significant increase in the pelvic floor strengths in both the groups but while comparing the post test results of both the groups there was a significant higher strength of contraction, length of hold, repetitions and fast contractions scores in experimental group.   Conclusion: It is evident from the study that performing the pelvic floor strengthening exercises in various positions as in the experimental group exhibited more improved post test results which proved to show reduced symptoms of urinary incontinence and improved quality of life than that of the subjects in the control group.

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer’s disease, and Parkinson’s disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

Urinary retention in diabetic older adults: mortality associated with a urinary catheter inserted during hospitalization but not removed

PURPOSE

We have studied, in diabetic older adults with urinary retention (UR), whether a urinary catheter (UC) inserted during hospitalization but not removed is associated with 1-year mortality.

METHODS

A retrospective study included 327 consecutive older adults (age ≥ 65 years; median age 83 years; 57.8% males) with UR in whom a UC was inserted during hospitalization: 139 (42.5%) diabetics and 188 (57.5%) nondiabetics. UC removal rates during hospitalization and 1-year mortality rates were studied in both groups. Cox regression analysis was used to assess whether a UC inserted during hospitalization but not removed was independently associated with 1-year mortality.

RESULTS

Most diabetic and non-diabetic patients left the hospital with a UC (66.2% vs. 75.5%; p = 0.082). Overall, 54 (38.8%) diabetic patients and 52 (27.7%) nondiabetic patients died one year later (OR 1.66; 95% CI 1.04-2.65; p = 0.042). Diabetic patients with a UC at discharge day had significantly higher 1-year mortality rates relative to diabetic patients without a UC (48.9% vs. 19.1%; OR 4.04; 95% CI 1.75-9.30; p = 0.001), while in nondiabetic patients there was no significant difference in 1-year mortality rates between patients with or without a UC at discharge day (26.8% vs. 30.4%; p = 0.705). Cox regression analysis showed that only in diabetic patients a UC not removed was independently associated with 1-year mortality (HR 2.56; 95% CI 1.16-5.64; p = 0.019).

CONCLUSION

A UC inserted but not removed in diabetic older adults with UR is associated with 1-year mortality. Removing a UC and its association with mortality should be studied prospectively in this population.

Urethral dysfunction and alterations of nitric oxide mechanisms in streptozotocin-induced diabetic rats with or without low-dose insulin treatment

AIMS

To establish an animal model of diabetes mellitus (DM) with moderately elevated blood glucose levels, and to examine the nitric oxide (NO) mechanism controlling urethral function in streptozotocin (STZ)-induced DM rats.

MAIN METHODS

Female Sprague-Dawley rats were used. DM was induced by intraperitoneal injection of STZ (65 mg/kg) and some of them received subcutaneous implantation of a low-dose insulin pellet. Voiding behavior was evaluated in metabolic cages. Isovolumetric cystometry and urethral perfusion pressure (UPP) were then evaluated under urethane anesthesia, during which L-arginine (100 mg/kg) and N-nitro-L-arginine methyl ester hydrochloride (L-NAME) (50 mg/kg) were administered intravenously. In vitro urethral activity was also tested by organ bath muscle strip studies.

KEY FINDINGS

UPP changes and high-frequency oscillation (HFO) were significantly (P < 0.05) smaller in 8-weeks DM rats vs. normal control (NC) rats or insulin-treated DM rats, which showed reductions in urine overproduction and voided volume per micturition vs. untreated DM rats. UPP nadir was decreased by L-arginine in NC and insulin-treated DM groups, and decreased by L-NAME in all groups. Five of 6 untreated DM rats showed a detrusor-sphincter dyssynergia pattern after L-NAME. In in vitro studies, the relative ratio of L-NAME-induced reductions of urethral relaxation against pre-drug urethral relaxation was significantly smaller in DM vs. NC rats (P < 0.05).

SIGNIFICANCE

Low-dose insulin-treated DM rats would be a useful model for studying natural progression of DM-induced lower urinary tract dysfunction. The impaired NO-mediated urethral relaxation mechanisms play an important role in DM-induced urethral dysfunction, which could contribute to DM-induced inefficient voiding.

How to optimise urinary continence in anatomical endoscopic enucleation of the prostate?

The traditional transurethral resection of the prostate (TURP) is considered as gold-standard surgical treatment to relieve symptoms resulting from bladder outlet obstruction by prostate enlargement. However, with the advances of novel laser technologies and more experienced surgeon conquering the steep learning curve, anatomical endoscopic enucleation of prostate (AEEP) has become a more popular alternative surgical technique. Although AEEP has compatible functional outcome, less blood loss, shorter catheterisation duration and hospital stay, the risk of post-operative urinary incontinence (UI) is often an issue of concern. In this review, we focus on discussion about risk factors related to increased incidence of UI, some surgical tips to avoid damaging external urinary sphincter and treatment strategies to facilitate recovery of urinary continence after surgery.

Study protocol to investigate biomolecular muscle profile as predictors of long-term urinary incontinence in women with gestational diabetes mellitus

BACKGROUND

Pelvic floor muscles (PFM) and rectus abdominis muscles (RAM) of pregnant diabetic rats exhibit atrophy, co-localization of fast and slow fibers and an increased collagen type I/III ratio. However, the role of similar PFM or RAM hyperglycemic-related myopathy in women with gestational diabetes mellitus (GDM) remains poorly investigated. This study aims to assess the frequency of pelvic floor muscle disorders and pregnancy-specific urinary incontinence (PS-UI) 12 months after the Cesarean (C) section in women with GDM. Specifically, differences in PFM/RAM hyperglycemic myopathy will be evaluated.

METHODS

The Diamater is an ongoing cohort study of four groups of 59 pregnant women each from the Perinatal Diabetes Research Centre (PDRC), Botucatu Medical School (FMB)-UNESP (São Paulo State University), Brazil. Diagnosis of GDM and PS-UI will be made at 24-26 weeks, with a follow-up at 34-38 weeks of gestation. Inclusion in the study will occur at the time of C-section, and patients will be followed at 24-48 h, 6 weeks and 6 and 12 months postpartum. Study groups will be classified as (1) GDM plus PS-UI; (2) GDM without PS-UI; (3) Non-GDM plus PS-UI; and (4) Non-GDM without PS-UI. We will analyze relationships between GDM, PS-UI and hyperglycemic myopathy at 12 months after C-section. The mediator variables to be evaluated include digital palpation, vaginal squeeze pressure, 3D pelvic floor ultrasound, and 3D RAM ultrasound. RAM samples obtained during C-section will be analyzed for ex-vivo contractility, morphological, molecular and OMICS profiles to further characterize the hyperglycemic myopathy. Additional variables to be evaluated include maternal age, socioeconomic status, educational level, ethnicity, body mass index, weight gain during pregnancy, quality of glycemic control and insulin therapy.

DISCUSSION

To our knowledge, this will be the first study to provide data on the prevalence of PS-UI and RAM and PFM physical and biomolecular muscle profiles after C-section in mothers with GDM. The longitudinal design allows for the assessment of cause-effect relationships between GDM, PS-UI, and PFMs and RAMs myopathy. The findings may reveal previously undetermined consequences of GDM.

Long-term diabetes causes molecular alterations related to fibrosis and apoptosis in rat urinary bladder

Diabetes induces time-dependent alterations in urinary bladders. Long-term diabetes causes an underactive bladder. However, the fundamental mechanisms are still elusive. This study aimed to examine the histological changes and the potential molecular pathways affected by long-term diabetes in the rat bladder. Diabetes was induced in 8-week-old male Lewis rats by streptozotocin, while age-matched control rats received citrate buffer only. Forty-four weeks after diabetes induction, bladders were harvested for histological and molecular analyses. The expressions of proteins related to fibrosis, apoptosis and oxidative stress as well as the cellular signaling pathway in the bladder were examined by immunoblotting. Histological examinations illustrated diabetes caused detrusor hypertrophy and fibrotic changes in the bladder. Immunoblotting analysis demonstrated higher collagen I but lower elastin expression in the bladder in diabetic rats. These were accompanied by an increase in the expression of transforming growth factor-beta1, along with the downregulation of matrix metalloptoteinase-1, and upregulation of tissue inhibitor of metalloproteinase-1. Diabetic rats showed an increase in nitrotyrosine, but decrease in nuclear factor erythroid-related factor 2 (Nrf2) levels in the bladder. Enhanced apoptotic signaling was observed, characterized by increased expression of Bcl-2-associated X protein (Bax), decreased expression of Bcl-2, in the diabetic bladder. The nerve growth factor level was decreased in the diabetic bladder. A significant suppression in the protein expressions of phosphorylated extracellular signal-regulated kinases 1/2 was found in diabetic bladders. This study demonstrated that long-term diabetes caused molecular changes that could promote fibrosis and apoptosis in the bladder. Oxidative stress may be involved in this context.

Time-Dependent Changes of Urethral Function in Diabetes Mellitus: A Review

This article reviewed the current knowledge on time-course manifestation of diabetic urethral dysfunction (DUD), and explored an early intervention target to prevent the contribution of DUD to the progression of diabetes-induced impairment of the lower urinary tract (LUT). In the literature search through PubMed, key words used included “diabetes mellitus,” “diabetic urethral dysfunction,” and “diabetic urethropathy.” Polyuria and hyperglycemia induced by diabetes mellitus (DM) can cause the time-dependent changes in functional and morphological manifestations of DUD. In the early stage, it promotes urethral dysfunction characterized by increased urethral pressure during micturition. However, the detrusor muscle of the bladder tries to compensate for inducing complete voiding by increasing the duration and amplitude of bladder contractions. As the disease progresses, it can induce an impairment of coordinated micturition due to dyssynergic activity of external urethra sphincter, leading to detrusor-sphincter dyssynergia. The impairment of relaxation mechanisms of urethral smooth muscles (USMs) may additionally be attributable to decreased responsiveness to nitric oxide, as well as increased USM responsiveness to α₁-adrenergic receptor stimulation. In the late stage, diabetic neuropathy may play an important role in inducing LUT dysfunction, showing that the decompensation of the bladder and urethra, which can cause the decrease of voiding efficiency and the reduced thickness of the urothelium and the atrophy of striated muscle bundles, possibly leading to the vicious cycle of the LUT dysfunction. Further studies to increase our understandings of the functional and molecular mechanisms of DUD are warranted to explore potential targets for therapeutic intervention of DM-induced LUT dysfunction.

Urothelial Senescence in the Pathophysiology of Diabetic Bladder Dysfunction-A Novel Hypothesis

Diabetic bladder dysfunction (DBD) is a well-recognized and common symptom affecting up to 50% of all diabetic patients. DBD has a broad range of clinical presentations ranging from overactive to underactive bladder symptoms that develops in middle-aged to elderly patients with long standing and poorly controlled diabetes. Low efficacy of current therapeutics and lifestyle interventions combined with high national healthcare costs highlight the need for more research into bladder dysfunction pathophysiology and novel treatment options. Cellular senescence is an age-related physiologic process in which cells undergo irreversible growth arrest induced by replicative exhaustion and damaging insults. While controlled senescence negatively regulates cell proliferation and promotes tissue regeneration, uncontrolled senescence is known to result in tissue dysfunction through enhanced secretion of inflammatory factors. This review presents previous scientific findings and current hypotheses that characterize diabetic bladder dysfunction. Further, we propose the novel hypothesis that cellular senescence within the urothelial layer of the bladder contributes to the pro-inflammatory/pro-oxidant environment and symptoms of diabetic bladder dysfunction. Our results show increased cellular senescence in the urothelial layer of the bladder; however, whether this phenomenon is the cause or effect of DBD is unknown. The urothelial layer of the bladder is made up of transitional epithelia specialized to contract and expand with demand and plays an active role in transmission by modulating afferent activity. Transition from normal functioning urothelial cells to secretory senescence cells would not only disrupt the barrier function of this layer but may result in altered signaling and sensation of bladder fullness; dysfunction of this layer is known to result in symptoms of frequency and urgency. Future DBD therapeutics may benefit from targeting and preventing early transition of urothelial cells to senescent cells.

Effect of 5-HT2A receptor antagonist ketanserin on micturition in male rats

OBJECTIVES

This study aimed to investigate the effects of ketanserin on micturition mediated via the 5-HT_2A receptor in the motoneuron nucleus of the Lumbosacral cord, as reflected in high frequency oscillations (HFOs) of intravesical pressure and the external urethral sphincter electromyogram (EUS-EMG) in anesthetized male rats. METHODS：: Male Sprague-Dawley rats were used. Cystometry and EUS-EMG were performed in all rats under urethane anesthesia to examine the variations after successive intrathecal (i.t.) administration of various doses of ketanserin into the lumbosacral cord. Immunofluorescence staining and Western blotting were made to observe the distribution of 5-HT2 A and -2C receptors in the lumbosacral cord motor neurons.

RESULTS

Compared to the controls, ketanserin-treated rats showed a declined trend of dose-dependent manner in the HFOs, in accordance with the variation of EUS-EMG, while decreased micturition volume, voiding efficiency, and increased post-void residual volume was only observed at the dose of 0.1 mg/kg. The effects of ketanserin on the HFO and EUS-EMG activity were partially or completely reversed by the 5-HT_2A/2C receptor agonist, DOI. Meanwhile, immunofluorescence staining and Western blot analysis showed that immunoreactivity of 5-HT_2A receptor was higher than that of 5-HT_2C, labeling in the lumbosacral cord motoneurons.

CONCLUSIONS

The intrathecally administrated 5-HT_2A receptor antagonist ketanserin can weaken the EUS bursting activity, decrease HFOs, and reduce voiding efficiency as dose dependently. The effects of ketanserin on micturition may be mainly mediated via the 5-HT_2A receptors in the motoneuron nucleus of the lumbosacral cord.

Path of translational discovery of urological complications of obesity and diabetes

Diabetes mellitus (DM) is a prevalent chronic disease. Type 1 DM (T1DM) is a metabolic disorder that is characterized by hyperglycemia in the context of absolute lack of insulin, whereas type 2 DM (T2DM) is due to insulin resistance-related relative insulin deficiency. In comparison with T1DM, T2DM is more complex. The natural history of T2DM in most patients typically involves a course of obesity to impaired glucose tolerance, to insulin resistance, to hyperinsulinemia, to hyperglycemia, and finally to insulin deficiency. Obesity is a risk factor of T2DM. Diabetes causes some serious microvascular and macrovascular complications, such as retinopathy, nephropathy, neuropathy, angiopathy and stroke. Urological complications of obesity and diabetes (UCOD) affect quality of life, but are not well investigated. The urological complications in T1DM and T2DM are different. In addition, obesity itself affects the lower urinary tract. The aim of this perspective is to review the available data, combined with the experience of our research teams, who have spent a good part of last decade on studies of association between DM and lower urinary tract symptoms (LUTS) with the aim of bringing more focus to the future scientific exploration of UCOD. We focus on the most commonly seen urological complications, urinary incontinence, bladder dysfunction, and LUTS, in obesity and diabetes. Knowledge of these associations will lead to a better understanding of the pathophysiology underlying UCOD and hopefully assist urologists in the clinical management of obese or diabetic patients with LUTS.

Functional and morphological alterations of the urinary bladder in type 2 diabetic FVB(db/db) mice

AIMS

Diabetic bladder dysfunction (DBD) has been extensively studied in animal models of type 1 diabetes. We aimed to examine the functional and morphological alterations of the urinary bladder in a type 2 diabetes model, FVB(db/db) mice.

METHODS

FVB(db/db) mice and age-matched FVB/NJ control mice were tested at either 12, 24 or 52weeks of age. Body weight, blood glucose and glycated hemoglobin (HbA1c) levels were measured. Bladder function was assessed by measurement of 24-h urination behavior and conscious cystometry. Bladder was harvested for Masson's Trichrome staining and morphometric analysis.

RESULTS

The body weights of FVB(db/db) mice were twice as those of FVB/NJ control mice. The blood glucose and HbA1c levels were higher in FVB(db/db) mice at 12 and 24weeks, but not at 52weeks. A significant increase in the mean volume per void, but decrease in the voiding frequency, in FVB(db/db) mice was observed. Cystometry evaluation showed increased bladder capacity, voided volume, and peak micturition pressure in FVB(db/db) mice compared with FVB/NJ mice. Morphometric analysis revealed a significant increase in the areas of detrusor muscle and urothelium in FVB(db/db) mice. In addition, some FVB(db/db) mice, especially males at 12 and 24weeks, showed small-volume voiding during 24-h urination behavior measurement, and detrusor overactivity in the cystometry measurement.

CONCLUSIONS

The FVB(db/db) mouse, displaying DBD characterized by not only increased bladder capacity, void volume, and micturition pressure, but also bladder overactivity, is a useful model to further investigate the mechanisms of type 2 diabetes-related bladder dysfunction.

Impaired Excitatory Neurotransmission in the Urinary Bladder from the Obese Zucker Rat: Role of Cannabinoid Receptors

Metabolic syndrome (MS) is a known risk factor for lower urinary tract symptoms. This study investigates whether functional and expression changes of cannabinoid CB₁ and CB₂ receptors are involved in the bladder dysfunction in an obese rat model with insulin resistance. Bladder samples from obese Zucker rat (OZR) and their respective controls lean Zucker rat (LZR) were processed for immunohistochemistry and western blot for studying the cannabinoid receptors expression. Detrusor smooth muscle (DSM) strips from LZR and OZR were also mounted in myographs for isometric force recordings. Neuronal and smooth muscle CB₁ and CB₂ receptor expression and the nerve fiber density was diminished in the OZR bladder. Electrical field stimulation (EFS) and acetylcholine (ACh) induced frequency- and concentration-dependent contractions of LZR and OZR DSM. ACh contractile responses were similar in LZR and OZR. EFS-elicited contractions, however, were reduced in OZR bladder. Cannabinoid receptor agonists and antagonists failed to modify the DSM basal tension in LZR and OZR In LZR bladder, EFS responses were inhibited by ACEA and SER-601, CB₁ and CB₂ receptor agonists, respectively, these effects being reversed by ACEA plus the CB₁ antagonist, AM-251 or SER-601 plus the CB₂ antagonist, AM-630. In OZR bladder, the inhibitory action of ACEA on nerve-evoked contractions was diminished, whereas that SER-601 did not change EFS responses. These results suggest that a diminished function and expression of neuronal cannabinoid CB₁ and CB₂ receptors, as well as a lower nerve fiber density is involved in the impaired excitatory neurotransmission of the urinary bladder from the OZR.

Effects of short-term severe and long-term mild STZ-induced diabetes in urethral tissue of female rats

AIMS

To estimate and compare the alterations in the urethral tissues of female rats with two diabetes models: short-term severe and long-term mild diabetes.

METHODS

To induce mild diabetes (blood glucose levels between 120 and 300 mg/dl), female newborns received streptozotocin (100 mg/kg body weight, sc route), and to induce short-term severe diabetes (blood glucose levels > 300 mg/d), adult animals received streptozotocin (40 mg/kg, iv route). The rats were killed on day 133 of the experimental via an i.p. Thiopentax^® injection of 80 mg/kg, and the urethrovaginal tissues were harvested. Morphometric, pathological, immunohistochemical, and ultrastructural analyses were conducted.

RESULTS

In the long-term mild diabetes group, collagen deposition, severe fibrosis, lipid droplets and numerous subsarcolemmal, and intermyofibrillar mitochondria were observed. In the short-term severe diabetes group, centrally located myonuclei and a significantly reduced striated muscle area were noted. Both diabetic models exhibited similar immunohistochemistry patterns, with changes from fast to slow fibers and a decrease in the numbers of fast fibers.

CONCLUSIONS

Either long-term mild hyperglycemia or short-term severe hyperglycemia have detrimental impacts on muscle health. They are both involved in the failure to maintain healthy skeletal muscle that may contribute to the development of pelvic floor dysfunctions via different pathways. These results have important implications for monitoring and prevention strategies for improving the quality of life of women with diabetes mellitus and pelvic floor muscle dysfunction. Neurourol. Urodynam. 36:574-579, 2017. © 2016 Wiley Periodicals, Inc.

Characterization of bladder and external urethral activity in mice with or without spinal cord injury--a comparison study with rats

To clarify the lower urinary tract function in mice, we compared bladder and urethral activity between rats and mice with or without spinal cord injury (SCI). Female Sprague-Dawley rats and C57BL/6N mice were divided into five groups:1) spinal intact (SI) rats,2) SI mice,3) pudendal nerve transection (PNT) SI mice,4) spinal cord injury (SCI) rats, and 5) SCI mice. Continuous cystometry (CMG) and external urethral sphincter (EUS)-electromyogram (EMG) analyses were conducted under an awake, restrained condition. During voiding bladder contractions, SI animals exhibited EUS bursting with alternating active and silent periods, which, in rats but not mice, coincided with small-amplitude intravesical pressure oscillations in CMG recordings. In SI mice with bursting-like EUS activity, the duration of active periods was significantly shorter by 46% (32 ± 5 ms) compared with SI rats (59 ± 9 ms). In PNT-SI mice, there were no significant differences in any of cystometric parameters compared with SI mice. In SCI rats, fluid elimination from the urethra and the EUS bursting occurred during small-amplitude intravesical pressure oscillations. However, SCI mice did not exhibit clear EUS bursting activity or intravesical pressure oscillations but rather exhibited intermittent voiding with slow large-amplitude reductions in intravesical pressure, which occurred during periods of reduced EUS activity. These results indicate that EUS pumping activity is essential for generating efficient voiding in rats with or without spinal cord injury. However, EUS bursting activity is not required for efficient voiding in SI mice and does not reemerge in SCI mice in which inefficient voiding occurs during periods of reduced tonic EUS activity.

Effects of sacral nerve stimulation on postpartum urinary retention-related changes in rat bladder

OBJECTIVE

To examine the effect of sacral nerve stimulation (SNS) on the urodynamic function and molecular structure of bladders in rats following acute urinary retention (AUR) after parturition.

MATERIAL AND METHODS

Thirty primiparous rats were divided into three groups: postpartum, postpartum+AUR, and postpartum+AUR+SNS. AUR was achieved by clamping the distal urethra of a rat for 60 minutes. The postpartum+AUR+SNS group received electrical stimulation 60 minutes daily for 3 days after AUR. In addition to cystometric studies and external urethral sphincter electromyography, the expression of caveolins and nerve growth factor (NGF) and caveolae number in bladder muscle were analyzed.

RESULTS

The postpartum+AUR group has significantly greater residual volume than the postpartum group, but the residual volume decreased significantly after SNS treatment. The postpartum+AUR group had significantly lower peak voiding pressure, a longer bursting period and lower amplitude of electromyograms of external urethral sphincter activity than the postpartum and postpartum+AUR+SNS groups. The postpartum+AUR rats had higher NGF expression, lower caveolin-1 expression, and fewer caveolae in bladder muscle compared with the postpartum rats. Conversely, the caveolin-1 expression and caveolae number increased, and the NGF expression decreased after SNS treatment.

CONCLUSION

Bladder dysfunction after parturition in a rat model caused by AUR may be restored to the non-AUR structural and functional level after SNS treatment.

Evaluation of the relationship between the pelvic floor muscles and insulin resistance

PURPOSE

The aim of this study was to evaluate the pelvic floor muscles (PFMs) in women with insulin resistance (IR) using surface electromyography and to associate the results with insulin levels.

PATIENTS AND METHODS

Through an analytical, cross-sectional study, 86 women were evaluated and divided into two groups: a control group (n=35) and an IR group (n=51). Data were collected through detailed history-taking, physical examination, and biochemical analysis. Fasting insulin levels were used for diagnosing IR. Electromyography of the PFMs was used for analyzing the tone and maximal voluntary contraction (MVC). The measures of central tendency and linear regression models were used.

RESULTS

The average age was 25.3±4.5 years in the IR group and 27.2±4.4 years in the control group. The mean weight was 75.6±17.6 kg and 51.8±4.9 kg in the IR and control groups, respectively. Fasting insulin levels were 19.7±6.6 µIU/mL in the IR group and 5.4±1.8 µIU/mL in the control group (P<0.010). There were significant differences between the groups with regard to PFM tone (IR: 13.4±3.4 µV; control: 25.1±3.3 µV; P<0.001) and MVC (IR: 47.6±4.5 µV; control: 64.3±5.0 µV; P<0.001). Multiple linear regression analysis using the insulin levels as dependent variable showed a significant association for MVC (P=0.047), weight (P=0.017), and waist circumference (P=0.000).

CONCLUSION

Compared with the control group, the IR group showed lower electromyographic activity of the PFMs, and there was an association between insulin levels and electromyographic activity.

Diabetic cystopathy: A review

Herein we review and discuss epidemiological, clinical, and experimental studies on diabetic cystopathy, a common chronic complication of diabetes mellitus with a variety of lower urinary tract symptoms, providing directions for future research. A search of published epidemiological, clinical, or preclinical trial literature was performed using the key words "diabetes", "diabetic cystopathy", "diabetic bladder dysfunction", "diabetic lower urinary tract dysfunction", "diabetic detrusor instability". The classic symptoms of diabetic cystopathy are decreased bladder sensation, increased bladder capacity, and impaired bladder emptying with resultant increased post-void residual volume. However, recent clinical evidence indicates a presence of storage symptoms, such as overactive bladder symptoms. The pathophysiology of diabetic cystopathy is multifactorial, including disturbances of the detrusor, neuron, urothelium, and urethra. Hyperglycemia, oxidative stress, and polyuria play important roles in inducing voiding dysfunction in diabetic individuals. Treatment choice depends on clinical symptoms and urodynamic abnormalities. Urodynamic evaluation is the cornerstone of diagnosis and determines management strategies. Diabetes mellitus could cause a variety of lower urinary tract symptoms, leading to diabetic cystopathy with broadly varied estimates of the prevalence rates. The exact prevalence and pathogenesis of diabetic cystopathy remains to be further investigated and studied in multicenter, large-scaled, or randomized basic and clinical trials, and a validated and standardized workup needs to be made, improving diabetic cystopathy management in clinical practice. Further studies involving only female diabetics are recommended.

Urethral dysfunction due to alloxan-induced diabetes. Urodynamic and morphological evaluation

PURPOSE

To evaluate the effect of short and long term alloxan-induced diabetes on bladder and urethral function of female rats, and also describing its correlated morphological alterations.

METHODS

Thirty five female rats were divided into three groups: G1 (n=9), control group; G2 (n=17), six weeks alloxan-induced diabetic rats; G3 (n=9), 20 weeks alloxan-induced diabetic rats. Functional evaluation was performed by cystometry and simultaneous measurements of the urethral pressure during bladder filling and voiding. Morphological evaluation was also performed with measurement of bladder and urethral fibrosis and collagen content and thickness of lamina propria and smooth muscle layers.

RESULTS

The peak bladder pressures and contraction amplitudes were decreased in 100% and 47% of the G3 and G2 groups respectively, when compared to control. Bladder overactivity was observed in 53% of the G2 group.

CONCLUSION

Alloxan-induced diabetes urethropathty in female rat was associated to bladder morphological alterations as higher thicknesses of it lamina propria, detrusor and adventicea.

Does diabetes affect the distribution and number of interstitial cells and neuronal tissue in the ureter, bladder, prostate, and urethra of humans?

INTRODUCTION

The aim of this study was to investigate and compare the distribution and number of interstitial cells (ICs) and neuronal tissue in the ureter, bladder, prostate, and urethra of human patients with and without diabetes.

MATERIAL AND METHODS

Human tissue was obtained from patients who had undergone radical cystectomy for bladder cancer (10 diabetic and 11 non-diabetic males). Interstitial cells were stained immunohistochemically with anti-human CD117 (c-kit) rabbit polyclonal antibody, Vimentin, and Connexin-43. Neural tissue was stained with synaptophysin. The number of ICs and neurons was evaluated and compared between the groups (diabetic versus non-diabetic).

RESULTS

The mean number of c-kit (+) ICs in bladder lamina propria was significantly decreased in diabetics (32.40 ±12.96 versus 57.18 ±25.37, p = 0.036). The mean number of ICs in the detrusor muscle was significantly decreased in diabetics (40.50 ±16.79 versus 64.55 ±22.08, p = 0.013). Between the groups, no significant differences were detected regarding the number of ICs at the level of the ureter, urethra, and prostate. No significant differences were detected regarding the number of nerves in the ureter, bladder, prostate, and urethra of both groups.

CONCLUSIONS

The number of ICs may be decreased in the lamina propria and detrusor muscle of the human bladder in diabetes. This can be an underlying cause of lower urinary tract (LUT) dysfunction in diabetics. Research into the development of drugs targeting or stimulating IC function in order to prevent diabetic LUT dysfunction is warranted.

[Translational research in gestational diabetes mellitus and mild gestational hyperglycemia: current knowledge and our experience]

Maternal diabetes constitutes an unfavorable environment for fetal-placental and embryonic development. It is has important repercussion in modern obstetrics, since it is associated to an increased risk of neonatal and maternal morbidity, and it still is a significant medical challenge. The increased occurrence of diabetes worldwide, the increase in diabetes type 2 in women at reproductive age and the crossed generation of intrauterine programming for diabetes type 2 are the bases for the growing interest in utilization of diabetic experimental samples, with the aim to acquire knowledge about the mechanisms that induce development alterations in gestational diabetes. Several studies have shown the benefits of diabetes prevention, with interventions in lifestyle, metabolic improvement and control of cardiovascular risk factors to substantially prevent the complications of this devastating disease. Despite these findings, the recent revolution in the scientific knowledge, and the infinite number of new therapies for diabetes, there is still a large gap between what was learned through research and what is really done in public, clinical and community health. The negative economic impact of this complacency in people, families, and national economies is alarming. It is expected that translational research in the binomial diabetes and pregnancy are implemented in centers of excellence, in both basic and applied research, and complemented by multicenter clinical studies, conducted in a pragmatic way to increase the level of scientific evidence with more reliable diagnostic and propaedeutic resources.

Changes in alpha1-adrenoceptor and NGF/proNGF pathway: a possible mechanism in diabetic urethral dysfunction

OBJECTIVE

To investigate the changes in the α1-adrenoceptor and nerve growth factor (NGF)/NGF precursor (proNGF) pathway in the urethra after diabetes induction.

MATERIALS AND METHODS

Urethral relaxation function was determined by simultaneous recordings of intravesical pressure under isovolumetric conditions and urethral perfusion pressure (UPP) in diabetic rats. The expression of α1-adrenoceptor, NGF, proNGF, low-affinity p75 receptor for neurotrophins (p75(NTR)) and sortilin in the urethras was measured using real-time quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay and Western blotting.

RESULTS

In diabetic rats, the lowest urethral pressure (UPP nadir) during urethral relaxation was significantly higher. Intravenous administration of tamsulosin, an α1-adrenoceptor antagonist, significantly decreased the UPP nadir and baseline UPP in diabetic rats. RT-qPCR and Western blotting studies showed a statistically significant increase of α1a- and α1b-adrenoceptor in the urethras from the diabetic group (p < 0.05). The expression of NGF was significantly decreased in the urethras from the diabetic group while the expression of proNGF was significantly increased (p < 0.05). The p75(NTR) level in the urethras of diabetic rats was decreased compared with controls (p < 0.05) and there was no significant difference regarding sortilin between the two groups (p > 0.05).

CONCLUSION

This study validated the diabetic urethral dysfunction and furthermore indicated that the increase in the expression of α1-adrenoceptor and changes in the NGF/proNGF pathway may be involved in diabetic urethral dysfunction.

Roles of polyuria and hyperglycemia in bladder dysfunction in diabetes

PURPOSE

Diabetes mellitus causes diabetic bladder dysfunction. We identified the pathogenic roles of polyuria and hyperglycemia in diabetic bladder dysfunction in rats.

MATERIALS AND METHODS

A total of 72 female Sprague-Dawley® rats were divided into 6 groups, including age matched controls, and rats with sham urinary diversion, urinary diversion, streptozotocin induced diabetes mellitus after sham urinary diversion, streptozotocin induced diabetes mellitus after urinary diversion and 5% sucrose induced diuresis after sham urinary diversion. Urinary diversion was performed by ureterovaginostomy 10 days before diabetes mellitus induction. Animals were evaluated 20 weeks after diabetes mellitus or diuresis induction. We measured 24-hour drinking and voiding volumes, and cystometry. Bladders were harvested to quantify smooth muscle, urothelium and collagen. We measured nitrotyrosine and Mn superoxide dismutase in the bladder.

RESULTS

Diabetes and diuresis caused increases in drinking and voiding volume, and bladder weight. Bladder weight decreased in the urinary diversion group and the urinary diversion plus diabetes group. The intercontractile interval, voided volume and compliance increased in the diuresis and diabetes groups, decreased in the urinary diversion group and further decreased in the urinary diversion plus diabetes group. Total cross-sectional tissue, smooth muscle and urothelium areas increased in the diuresis and diabetes groups, and decreased in the urinary diversion and urinary diversion plus diabetes groups. As a percent of total tissue area, collagen decreased in the diuresis and diabetes groups, and increased in the urinary diversion and urinary diversion plus diabetes groups. Smooth muscle and urothelium decreased in the urinary diversion and urinary diversion plus diabetes groups. Nitrotyrosine and Mn superoxide dismutase increased in rats with diabetes and urinary diversion plus diabetes.

CONCLUSIONS

Polyuria induced bladder hypertrophy, while hyperglycemia induced substantial oxidative stress in the bladder, which may have a pathogenic role in late stage diabetic bladder dysfunction.

Influence of High Fat Diet Feeding for 20 Weeks on Lower Urinary Tract Function in Mice

OBJECTIVES

We investigated the possible changes in lower urinary tract function in mice fed a high fat diet (HFD).

METHODS

Male C57BL/6J mice were divided into two different feed groups: normal diet (ND) and HFD (n = 16 in each). The body weight, blood glucose level and voiding frequency/volume (FV) relations (for 24 h) were measured every 4 weeks. At 25 weeks old, blood pressure and heart rate, cystometry and isolated detrusor smooth muscle function were measured. After the experiments, serum fat level was measured.

RESULTS

The body weight and blood glucose level of the HFD group were significantly higher than those of the ND group after 9 weeks old. In the FV measurements, the mean voided volume was not significantly different between the two groups, although voiding frequency, total voided volume and water intake volume in the HFD group were significantly lower than those in the ND group. At 25 weeks old, the mean heart rate in the HFD group was significantly higher than that in the ND group, but no significant difference in the blood pressure was observed. None of the cystometric parameters analyzed showed significant differences between the two groups. The contractile response to either carbachol or high K(+) was not significantly different, whereas the contractile response to electrical field stimulation was significantly higher in the HFD group. In the HFD group, the mean total cholesterol level was significantly higher.

CONCLUSION

The present results suggest that HFD-feeding for 20 weeks in mice unlikely affects bladder function even though it induced diabetes, hyperlipidemia and tachycardia.

Pudendal neuromodulation improves voiding efficiency in diabetic rats

AIMS

Diabetic cystopathy is typically manifested as bladder voiding dysfunction, and numerous patients are refractory to standard therapy. In this study, we determined whether electrical stimulation (ES) of the sensory branch of the pudendal nerve could engage an augmenting reflex and thereby improve bladder emptying in a diabetic animal model with cystopathy.

METHODS

The efficiency of bladder emptying with ES of the sensory branch of the pudendal nerve at different stimulation intensities was measured in rats at 8 or 18 weeks after the induction of diabetes with streptozotocin.

RESULTS

The voiding efficiency (VE) was reduced from 74 ± 4% to 30 ± 8% in rats with diabetes for 8 weeks and from 73 ± 6% to 20 ± 6% in rats with diabetes for 18 weeks. ES at lower intensities (0.025-0.05 mA) applied to the pudendal sensory nerve did not affect the VE in rats with diabetes for 18 weeks but increased the VE in rats with diabetes for 8 weeks. Subsequently, when the stimulation intensity was elevated to 0.1-0.3 mA, the VEs in rats with diabetes for both 8 and 18 weeks increased to 40-50%.

CONCLUSIONS

The results of the present study are consistent with the essential role for pudendal sensory feedback in efficient bladder emptying, and electrical activation of the sensory branch of the pudendal nerve was efficient restoring the voiding function in diabetic animals with cystopathy. This could provide an approach to improve bladder emptying in diabetic patients with voiding dysfunction.

Calcineurin and Akt expression in hypertrophied bladder in STZ-induced diabetic rat

Diabetes causes significant increases in bladder weight but the natural history and underlying mechanisms are not known. In this study, we observed the temporal changes of detrusor muscle cells (DMC) and the calcineurin (Cn) and Akt expressions in detrusor muscle in the diabetic rat. Male Sprague-Dawley rats were divided into 3 groups: streptozotocin-induced diabetics, 5% sucrose-induced diuretics, and age-matched controls. The bladders were removed 1, 2, or 9weeks after disease induction and the extent of hypertrophy was examined by bladder weights and cross sectional area of DMC. Cn and Akt expression were evaluated by immunoblotting. Both diabetes and diuresis caused significant increases in bladder weight. The mean cross sectional areas of DMC were increased in both diabetic and diuretic animals 1, 2, or 9weeks after disease induction. The expression levels of both the catalytic A (CnA) and regulatory B (CnB) subunits of Cn were increased at 1 and 2weeks, but not at 9weeks. Expression of Akt was similar among control, diabetic, and diuretic rat bladder at all time points. In conclusion, diabetes and diuresis induce similar hypertrophy of detrusor muscle during the first 9weeks, indicating that bladder hypertrophy in the early stage of diabetes is in response to the presence of increased urine output in diabetes. Our results suggest that the Cn, but not the Akt signaling pathway may be involved in the development of bladder hypertrophy.

Histologic study of urethral extracellular matrix and collagen from aging and long-term alloxan-induced diabetic male rats

OBJECTIVES

To evaluate the histological alterations of extracellular matrix in long-term alloxan-induced diabetes and aging urethras of male rats with descriptions of total connective tissue, muscle layer and collagen types I and III relative amounts.

METHODS

Histologic evaluations were performed in 3 animal groups: group 1, 8 weeks old; group 2, 44 weeks old; and group 3, 44 weeks old with alloxan-induced diabetes. The muscle layer thickness, extracellular matrix fibrosis, and collagen were quantified on digital images of the urethral samples.

RESULTS

A higher total thickness and muscle layer thickness and higher connective tissue and collagen content were observed in the urethras of group 3. No changes in the collagen type III/I ratio were found in the urethra of groups 2 and 3.

CONCLUSIONS

Our results suggest that the morphologic alterations of the urethra should also be considered in long-term studies of diabetic lower urinary tract dysfunction. These morphologic alterations due to diabetes differ from the changes induced by aging itself and could represent a final stage in decompensate urethras. Further studies are necessary to establish the real influence of the urethral morphologic changes on lower urinary tract diabetes dysfunction.

Pudendal nerve injury reduces urethral outlet resistance in diabetic rats

Diabetics have voiding and continence dysfunction to which elevated levels of advanced glycation end products (AGE) may contribute. In addition, pudendal nerve injury is correlated with voiding dysfunction and stress incontinence in rats. The aim of this study was to investigate whether pudendal nerve crush (PNC) in diabetic rats alters urinary function. Female virgin Sprague-Dawley rats (144) were divided equally into diabetic, diuretic, and control groups. Half of the animals in each group were subjected to PNC, and the other half to sham PNC. Diabetes was induced 8 wk before PNC or sham PNC by streptozotocin injection (35 mg/kg). Animals underwent conscious cystometry and leak point pressure (LPP) testing 4 or 13 days after PNC or sham PNC. Tissues of half the animals were tested for levels of AGEs. Qualitative histological assessment was performed in the remaining animals. Diabetic rats 4 days after PNC voided significantly greater volume in a shorter time and with significantly less pressure than after sham PNC, suggesting that diabetic rats have a functional outlet obstruction that is relieved by PNC. LPP was significantly reduced 4 days after PNC in diabetic and diuretic animals and returned to normal 13 days after PNC. Diabetic rats with PNC demonstrated increased muscle fiber disruption and atrophy of the external urethral sphincter. AGEs were significantly elevated in diabetic rats. PNC relieves a functional outlet obstruction in diabetic rats. AGEs are elevated in diabetic rats and could play a role in urinary dysfunction and recovery from PNC.

Exercise improves bladder function in diabetic mice

AIMS

We determined the effect of exercise on bladder dysfunction and voiding frequency in db/db mice.

MATERIALS AND METHODS

Diabetic db/db female mice (BKS.Cg-Dock7m +/+ Leprdb/J strain) and their age-matched wild-type controls (WT) were equally divided into sedentary and exercise groups. Mice were exercised for 1 hr everyday for 8 weeks (speed of 5.2 m/min). We performed a voiding pattern test, cystometric analysis and reactivity of isolated bladder strips in WT and db/db mice, both sedentary and exercised.

RESULTS

Diabetes increased the frequency of voiding, bladder capacity, and residual volume. Exercise decreased voiding frequency in db/db mice; voiding frequency was 5.8 ± 0.5 (db/db exercise) versus 10.8 ± 1.1 (db/db control, P < 0.001). In cystometric analysis, the bladder capacity of db/db sedentary mice was 0.27 ± 0.05 ml and was 0.14 ± 0.02 ml in the db/db exercise group (P < 0.05), whereas the residual volume was 0.2 ± 0.03 ml in db/db sedentary mice and 0.06 ± 0.02 ml in db/db Ex mice. Isolated strips of bladder muscle from sedentary db/db mice were more responsive to carbachol than strips from db/db exercise mice. Exercise did not improve the urodynamic properties of WT mice, both sedentary and exercised.

CONCLUSIONS

Exercise improves bladder function in diabetic mice by reducing voiding frequency and improving urodynamic parameters.

Diabetic bladder dysfunction: current translational knowledge

PURPOSE

Diabetes mellitus, a metabolic disorder caused by an absolute or relative deficiency of insulin, is a debilitating and costly disease with multiple serious complications. Lower urinary tract complications are among the most common complications of diabetes mellitus. The most common, bothersome lower urinary tract complication of diabetes mellitus is diabetic cystopathy or diabetic bladder dysfunction. We reviewed the current translational knowledge of diabetic bladder dysfunction.

MATERIALS AND METHODS

We performed a search of the English literature through PubMed. The key words used were diabetes and bladder dysfunction or cystopathy. Our data and perspective are provided for consideration of the future direction of research.

RESULTS

Despite traditional recognition of diabetic bladder dysfunction as a voiding problem characterized by poor emptying and overflow incontinence, recent clinical and experimental evidence indicate storage problems such as urgency and urge incontinence in diabetes mellitus cases. Recent experimental evidence from studies of diabetic bladder dysfunction in small animal models of diabetes mellitus show a temporal effect on diabetic bladder dysfunction. Early phase diabetes mellitus causes compensated bladder function and the late phase causes decompensated bladder function. The temporal theory could plausibly provide the scientific road map to correlate clinical and experimental findings, and identify the role of mechanisms such as polyuria, hyperglycemia, oxidative stress, autonomic neuropathy and decompensation of the bladder contractile apparatus in the creation of clinical and experimental manifestations of diabetic bladder dysfunction.

CONCLUSIONS

Diabetic bladder dysfunction includes time dependent manifestations of storage and emptying problems. Identifying mechanistic pathways would lead to the identification of therapeutic intervention.

Does diabetes affect the intensity of staining of interstitial cells and neuronal tissue in the bladder, prostate and urethra of rabbits?

We compared the intensity of staining of interstitial cells (ICs) and neural tissue in the lower urinary tract of rabbits with diabetes with the intensity in normal subjects. Diabetes was induced by injecting alloxane (65mg/kg) in adult male rabbits. After 3 days, rabbits with a blood glucose level >300 mg/dL were considered to have diabetes. After 8 weeks, the rabbits were killed, and tissue specimens from the bladder, prostate and urethra were obtained. ICs were stained with anti-human CD117 (c-kit) rabbit polyclonal antibody, and neural tissue was stained with synaptophysin. The streptavidin-biotin method was used for immunohistochemical staining. The intensity of c-kit and synaptophysin staining were scored as negative (0), weak (+), moderate (++), and strong (+++). Staining intensity of ICs and neural tissue was assessed and compared in tissues obtained from rabbits with diabetes (n=8) and from control subjects (n=7). Although staining intensity of both ICs and neural tissue was found to be significantly decreased in the bladder tissue of rabbits with diabetes compared to that in the control group (p=0.0001 [ICs] and p=0.021 [neural tissue]), no significant differences in staining intensity of ICs and neural tissue in the urethra and in the prostate was found when rabbits with diabetes were compared to the control group. Diabetes may cause dysfunction of the lower urinary tract, particularly in the urinary bladder, as shown by the staining intensity of ICs and neural tissue.

Voiding function in obese and type 2 diabetic female rats

The effects of obesity and type 2 diabetes (DMII) on the lower urinary tract (LUT) were characterized by evaluating voiding function and anatomy in female Zucker diabetic fatty (ZDF) rats. Age-matched female virgin rats were separated into three experimental groups: Zucker lean rats (control; normal diet, n = 22), ZDF rats (obese+nondiabetic; low-fat diet, n = 22), and ZDF rats (obese+diabetic; high-fat diet, n = 20). Rats were placed on their specified diet for 10 wk before urodynamic LUT evaluation. A suprapubic catheter was implanted 2 days before urodynamic studies. Voiding function was evaluated by cystometric and leak point pressure (LPP) testing. The bladder, urethra, and vagina were immediately excised for qualitative histological evaluation. Compared with control rats, obese+nondiabetic and obese+diabetic rats had significantly decreased contraction pressure ( P = 0.003) and increased cystometric filling volume ( P < 0.001). Both obese groups exhibited significantly higher voided volumes ( P = 0.003), less frequent urinary events ( P < 0.001), and increased residual volumes ( P = 0.039). LPP studies showed a nonsignificant decrease in LPP ( P = 0.075) and baseline pressure ( P = 0.168) in both obese groups compared with control. Histology of the external urethral sphincter in obese rats showed increased fibrosis, leading to disruption of the skeletal muscle structure compared with control. Additionally, the bladder wall of the obese+nondiabetic and obese+diabetic rats demonstrated edema and vasculopathy. Voiding dysfunction was evident in both obese groups but with no significant differences due to DMII, suggesting that voiding dysfunction in DMII may be attributable at least in part to chronic obesity.