Obstructive Bladder Dysfunction: Morphological, Biochemical and Molecular Changes

Expression of Toll-Like Receptors in the Animal Model of Bladder Outlet Obstruction

Introduction

Bladder outlet obstruction (BOO) occurs in more than 20 percent of the adult population and may lead to changes in the structure and function of the bladder. The main objective of the study was to evaluate the expression of Toll-like receptor 4 (TLR 4) and Toll-like receptor 9 (TLR 9) in the animal model of BOO as potential triggers of the inflammation phase in the bladder. In addition, the modulating effect of alpha-1 adrenergic antagonist (tamsulosin) on TLR 4 and TLR 9 expression and inflammatory markers was assessed. Material and Methods. Thirty-two male, 9-week-old Sprague Dawley rats were randomly divided into 4 groups: SOP—sham-operated rats with a placebo (water); SOB—sham-operated rats with an alpha-1 adrenergic antagonist; BOOP—rats with BOO and a placebo; and BOOB—rats with BOO and an alpha-1 adrenergic antagonist. The rats were given a placebo or alpha-1 adrenergic antagonist for 15 days. Next, urine and the bladder were collected from the rats for histopathological and biochemical study.

Results

Histopathological analysis showed chronic inflammation without acute inflammation in the bladder. TLR 4 showed positive cytoplasmic reactivity in the urothelium and the smooth muscles of the bladder. TLR 9 showed positive cytoplasmic reactivity only in the urothelium. BOO caused an increase in TLR 4 and TLR 9 expression. Furthermore, treatment with an alpha-1 adrenergic antagonist had no significant effect on TLR 4 and TLR 9 expression in rats with BOO. BOO caused a significant increase in urine concentration of interleukin 6 (IL-6), while alpha-1 antagonist reduced the urine concentration of IL-6 and the concentration of interleukin 18 (IL-18).

Conclusions

The results suggest the participation of TLR 4 and TLR 9 receptors in the induction of inflammation in the bladder, which is the first phase in the development of pathophysiological changes in BOO.

Relationship between post-void residual urine volume, preoperative pyuria and intravesical recurrence after transurethral resection of bladder carcinoma

OBJECTIVES

To evaluate the relationship between residual urine volume, pyuria and bladder carcinoma recurrence.

METHODS

The clinical data of 305 patients who had post-void residual urine volume measured and preoperative pyuria were retrospectively collected. The patients were classified into three risk groups based on the presence of residual urine and pyuria: good (negative residual urine and pyuria), intermediate (positive residual urine or pyuria) and poor (positive residual urine and pyuria). Predictive factors for intravesical recurrence-free survival were statistically analyzed using Cox proportional hazard models and Kaplan-Meier methods. The propensity score matching method was used to adjust the patients' backgrounds.

RESULTS

The median follow-up period for all patients was 44 months. The presence of residual urine (P = 0.0164) and pyuria (P = 0.0233) were two independent prognostic factors for recurrence. After patients were classified into risk groups, the poor-risk group showed significantly shorter recurrence-free survival compared with that of the good- (P = 0.0002) and intermediate-risk groups (P = 0.0090). Even after matching, the presence of residual urine was related to short recurrence-free survival in male patients (P = 0.0012). When stratified by European Organization for Research and Treatment of Cancer risk groups, the presence of pyuria was related to short recurrence-free survival, especially for intermediate-risk patients without bacillus Calmette-Guérin treatment.

CONCLUSIONS

Post-void residual urine and preoperative pyuria are two risks for recurrence-free survival in non-muscle-invasive bladder cancer.

Evaluation of a rat model of functional urinary bladder outlet obstruction produced by chronic inhibition of nitric oxide synthase

AIMS

Ligation of the urethra to create partial bladder outlet obstruction has widely been used as an animal model of bladder obstruction, although obstructive bladder dysfunction may be due to both mechanical and functional obstruction. Previous studies in rodents have demonstrated that long-term nitric oxide (NO) deficiency can lead to detrusor overactivity, and lack of NO may thus cause impairment of bladder outlet relaxation. The aim of this study was to define the characteristics of bladder and urethral dysfunction induced by chronic NO deficiency through both in vivo and in vitro investigations.

MAIN METHODS

Rats were divided into two groups, and one group received an NO synthase inhibitor (N_ω-nitro-L-arginine methyl ester hydrochloride: L-NAME) in the drinking water for 4 weeks. Bladder and urethral function were evaluated by continuous cystometry and isovolumetric cystometry. In vitro functional studies of detrusor strips and measurement of the mRNA and protein expression of an ischemic marker and a gap junction protein were also performed in separate rats.

KEY FINDINGS

L-NAME administration raised blood pressure and decreased plasma nitrite/nitrate level compared to the control group. L-NAME treatment increased the frequency of bladder contractions and the residual volume, and elevated urethral pressure and bladder contraction pressure. In addition, carbachol-induced contraction was reduced in isolated detrusor strips from the L-NAME group, and bladder expression of HIF-1 and connexin 43 showed upregulation.

SIGNIFICANCE

These findings suggest that chronic administration of L-NAME to rats induces bladder hyperactivity with residual urine, and may provide a useful model of functional bladder obstruction.

Impact of post-void residual urine volume on intravesical recurrence after nephroureterectomy for upper urinary tract urothelial carcinoma

OBJECTIVE

To examine the impact of post-void residual urine volume on the risk of postoperative recurrence of intravesical carcinoma in patients with upper urinary tract urothelial carcinoma undergoing nephroureterectomy.

METHODS

We retrospectively reviewed the data of 81 patients who were admitted to Chiba University Graduate School of Medicine Hospital and underwent nephroureterectomy for upper urinary tract urothelial carcinoma without bladder carcinoma. We assessed the predictive factors for intravesical recurrence after nephroureterectomy in all patients. Next, we compared patients with and without a residual urine volume using propensity score-matching analysis. The presence of a residual urine volume was defined as ≥30 mL.

RESULTS

The median follow-up period among all patients was 48 months. The presence of pyuria and a residual urine volume were associated with bladder recurrence in the multivariate analysis. A total of 19 patients each were selected after matching, and we confirmed a significant difference between the presence and absence of a residual urine volume (P = 0.0291). The 2-year postoperative recurrence-free rate of patients with and without a residual urine volume was 32% and 82%, respectively.

CONCLUSIONS

This is the first study to evaluate the post-void residual urine volume and intravesical recurrence rate after nephroureterectomy for upper urinary tract urothelial carcinoma. The presence of residual urine might be a risk factor for postoperative recurrence of intravesical carcinoma.

Effect of a high-fat diet on the rat bladder wall and bioactive action of Brazil nut oil

High-fat diet-induced obesity is associated with metabolic disorders. The Brazil nut has bioactive substances and has been used to control the damage caused by obesity in several organs. The work intended to show the damage caused by high-fat diet in the bladder wall and if the Brazil nut oil added to the diet could ameliorate or reverse this effect. Sixty-day-old rats were divided into two groups: C (control, n = 30) and HF (high-fat, n = 30) diets. At 90 days, 10 animals of each group were sacrificed. The others were divided into 4 groups: C and HF (animals that maintained their previous diet, n = 10 for each group) and C / Bno and HF / Bno (animals whose control or high-fat diet was supplemented by Brazil nut oil, n = 10 for each group). Sacrifice occurred at 120 days, and the bladders were removed and analyzed. Epithelial height was increased in the HF compared to the C group. In contrast, the C / Bno had a lower epithelial height compared to the others. The percentage of collagen between the detrusor muscle fibers was significantly greater in C / Bno, HF and HF / Bno than in control group. The HF had a larger muscle fiber diameter than the C group, while the C / Bno presented lower values than the HF and HF / Bno groups. HF diets induced bladder wall damage. These changes in the rat's bladder wall were partially reversed by the Bno.

Stereological comparison of the effects of pentoxifylline, captopril, simvastatin, and tamoxifen on kidney and bladder structure after partial urethral obstruction in rats

Purpose

Limited studies have shown antifibrotic effects of pentoxifylline, captopril, simvastatin, and tamoxifen. No comparisons are available of the effects of these drugs on prevention of renal and bladder changes in partial urethral obstruction (PUO).

Materials and Methods

The rats were divided into six groups (n=7). The sham-operated rats (group I) only underwent laparotomy and did not receive any treatments. The PUO groups (group II-VI) received normal saline (PUO+NS), pentoxifylline (100 mg/kg/d; PUO+PEN), captopril (35 mg/kg/d; PUO+CAP), simvastatin (15 mg/kg/d; PUO+SIM), or tamoxifen (10 mg/kg/d; PUO+TAM) by gavage for 28 days. Then, the volume and/or length of the kidney components (tubules, vessels, and fibrous tissue) and the bladder components (epithelial and muscular layers, fibrous tissue, fibroblast and fibrocyte number) were quantitatively evaluated on the microscopic sections by use of stereological techniques.

Results

The volume of renal and bladder fibrosis was significantly ameliorated in the PUO+PEN group, followed by the PUO+CAP, PUO+SIM, and PUO+TAM groups. Also, the volume and length of the renal tubules and vessels and bladder layers were more significantly protected in the PUO+PEN group, followed by the PUO+CAP, PUO+SIM, and PUO+TAM groups.

Conclusions

Treatment of PUO with PEN was more effective in the prevention of renal and bladder fibrosis and in the preservation of renal and bladder structures.

Which patients are at higher risk for residual valves after posterior urethral valve ablation?

Purpose

To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation.

Materials and Methods

We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups.

Results

Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups.

Conclusions

In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.

Bladder outlet obstruction accelerates bladder carcinogenesis

OBJECTIVE

To examine the correlation between partial bladder outlet obstruction (PBOO) and bladder carcinogenesis.

MATERIALS AND METHODS

Female Wistar rats (6 weeks old) were divided into three groups of 10 each: group 1 was exposed to n-butyl-n-butanol nitrosamine (BBN, a carcinogen) in drinking water for 8 weeks; group 2 had PBOO induced surgically after exposure to BBN for 8 weeks; group 3 had a sham operation and the rats drank normal water (control group). After 20 weeks, all of the rats were killed humanely and their bladders analysed.

RESULTS

There were no significant differences in body weight among the groups. The bladder weight of group 2 was significantly greater than either group 1 or group 3. Histopathologically, bladder smooth muscle hypertrophy was the major cause of the increased bladder weight for group 2. In group 2 there were increases in bladder wall thickness and many nipple-shaped urothelial tumours. Basic fibroblast growth factor and hypoxia-inducible factor-1alpha expression were significantly greater in group 2 than in groups 1 and 3.

CONCLUSIONS

Exposure of the bladder to carcinogens during bladder hyperplasia and hypertrophy induced by PBOO results in a greater incidence of superficial bladder carcinoma.

Effect of age on the role of Rho-kinase in short-term partial bladder outlet obstruction

OBJECTIVES

We examined the expression of Rho-kinase (ROK) isoforms in young and old rabbits' detrusor smooth muscles (SM) during the progression of short-term partial bladder outlet obstruction and correlated them with the time course of obstruction.

METHODS

We obtained detrusor samples from bladders after 1, 3, 7, and 14 days of obstruction and also sham-operated control rabbits. We used reverse transcriptase-polymerase chain reaction, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blotting to determine the relative levels of ROK isoform expression at the mRNA and protein levels.

RESULTS

Bladder weight for young rabbits increased between 1 and 7 days' obstruction and came back toward control levels at 14 days' obstruction. In old rabbits, bladder weight increased after obstruction, reaching a maximum at 3 days and remaining at this level throughout the 14 days. In young rabbits, the expression of ROKalpha increased in 1- to 7-day obstructed groups and decreased in the 14-day group, whereas it increased progressively in the old rabbits at both the mRNA and protein levels. There was a significant decrease in the expression of ROKbeta in young obstructed rabbits, which gradually decreased during the course of 1- to 7-day obstruction period and increased after 14 days of obstruction. In old groups, there was a decrease in expression after 1 day of obstruction and values remained at a decreased level throughout the course of the study.

CONCLUSIONS

Young rabbit bladders are better able to adapt to bladder outlet obstruction and ROK isoforms respond in a similar way.

Effect of long-term partial bladder outlet obstruction on caldesmon isoforms and their correlation with contractile function

AIM

In the present study, we investigate the expression of caldesmon (CAD) isoforms in rabbit detrusor smooth muscles (DSM) during the progression of partial bladder outlet obstruction and relate them with the time course of obstruction.

METHODS

Detrusor samples were obtained from the bladders of rabbits with partial bladder outlet obstruction and sham-operated control rabbits after 1, 2, 4, and 8 weeks of obstruction. Contractile responses to field stimulation and carbachol were determined in the isolated bladder strips. Western blotting was used to determine the relative levels of CaD isoform expression at the protein levels.

RESULTS

The contractile responses decreased progressively over the course of obstruction. The expression of l-CaD increased significantly to approximately the same extent as the 1-4-week obstructed groups and further in the 8-week obstructed group. The expression of h-CaD increased in all of the obstructed bladders, but at significantly higher levels in the 1-2-week obstructed bladders compared to the control and 4-8-week obstructed bladders.

CONCLUSIONS

The changes in the isoforms of CaD may be part of the molecular mechanism for bladder compensation following partial bladder outlet obstruction. The overexpression of l-CaD and the h-CaD/l-CaD ratio could be markers for the status of DSM remodeling and dysfunction.

Effect of age on the response to short-term partial bladder outlet obstruction in the rabbit

OBJECTIVE

To compare the physiological and structural changes after short-term partial bladder outlet obstruction (PBOO) in young and old rabbits, as PBOO results in marked contractile and histological alterations in the bladder.

MATERIALS AND METHODS

In all, 20 young (7-8-week-old) and 20 old (2 years old) male rabbits were divided into four subgroups of five each (four obstructed and one sham control rabbit). The rabbits in the groups were evaluated after 1, 3, 7 and 14 days of PBOO, respectively. At the end of the respective periods, cystometry and contractile responses to field stimulation (FS), ATP, carbachol and potassium chloride were determined. Full-thickness sections of the bladder body and base were used to determine the vascular density, nerve density and smooth muscle/collagen ratios.

RESULTS

The bladder weight of young rabbits increased at 1-7 days of PBOO and returned toward control levels at 14 days of PBOO, while in old rabbits it was higher than the control during the entire experiment. For the young rabbits, the responses to field stimulation decreased progressively for 1, 3 and 7 days, and increased significantly at 14 days. For old rabbits there was a progressive decrease to a minimal response by 3 days of PBOO and the response remained at this level over 14 days. The contractile response to ATP, carbachol and KCl were similar to the responses to FS. The vascular density in both groups increased to a maximum at 7 days and then decreased toward control values at 14 days. For the young rabbits, nerve density decreased more than in old rabbits. In the old group, the smooth muscle/collagen ratio was increased throughout PBOO and was higher than in young rabbits. The connective tissue compartment was markedly greater than in the young rabbits and the basal mucosa had vacuoles which were not apparent in the young bladders.

CONCLUSIONS

This study shows that the adaptive changes to PBOO are faster in young rabbit bladders than in older rabbits.

Effect of aging on the response of biochemical markers in the rabbit subjected to short-term partial bladder obstruction

PURPOSE

Partial bladder outlet obstruction (PBOO) results in marked biochemical alterations in the bladder. In this study, we focused on comparison of thapsigargin sensitive sarco/endoplasmic reticulum Ca(2+) ATPase activity (SERCA) and Citrate Synthase after short term PBOO in young versus old rabbits.

MATERIALS AND METHODS

A total of 20 young and 20 mature male rabbits were divided into 4 sub-groups of 5 rabbits each (4 obstructed and 1 sham-control rabbit). The rabbits in the groups were evaluated after 1, 3, 7, and 14 days of obstruction, respectively. The activities of SERCA and citrate synthase were examined as markers for sarcoplasmic reticular calcium storage and release and mitochondrial function, respectively.

RESULTS

The SERCA activity of bladder body smooth muscle in the young animals increased at 7 and 14 days. For the old rabbits, the SERCA activity decreased significantly by 1 day and remained this level throughout the course of obstruction, and was significantly lower than young at all time periods. The citrate synthase activity in the young animals decreased over the 1-7 days, and then returned toward control level by 14 days following obstruction. In the old animals, citrate synthase activity of bladder body smooth muscle progressively decreased over the course of the study, and was significantly lower in the old than the young animals after 14 days obstructed.

CONCLUSION

The urinary bladders of the young rabbits have a considerable greater ability to adapt to PBOO than do those of the old rabbits. The deterioration of mitochondrial and SR function may be important mechanisms underlying geriatric voiding dysfunction.

Lower urinary tract symptoms, prostate volume, uroflowmetry, residual urine volume and bladder wall thickness in Turkish men: a comparative analysis

AIM

To evaluate the association between lower urinary tract symptoms (LUTS) severity and bladder wall thickness (BWT).

MATERIALS AND METHODS

The study included 155 patients referred to outpatient clinics for LUTS. Patients were divided into three groups due to their IPSS. Group A included the patients with mild symptoms, group B included patients with moderate symptoms and group C included patients with severe symptoms. The patients were again divided into two groups due to their uroflowmetry results. Group 1 included the patients whose Q (max) </= 10 ml/s and group 2 included the patients whose Q (max) > 10 ml/s.

RESULTS

The mean BWT was 4.14 + 1.03 mm (from 3 to 9 mm). Although there was no difference between the IPSS groups in BWT (P = 0.325), it was statistically significant between uroflowmetry study groups (P < 0.01).

CONCLUSIONS

BWT seems to be significantly increased in men who have Q (max) values smaller than 10 ml/s.

Effect of castration on male rabbit lower urinary tract tissue enzymes

OBJECTIVES

The influence of testosterone on the prostate and corpus cavernosum have been studied extensively. However, the influence of testosterone on the lower urinary tract (bladder and urethra) have not been investigated to any great extent. The aim of this study was to determine whether androgen deprivation alters lower urinary tract metabolism.

METHODS

A total of 16 rabbits were divided into four groups of four rabbits each. Each rabbit in groups 1-3 underwent surgical bilateral castration for duration of 1, 2 , and 4 weeks, and group 4 underwent sham operations. Sections of bladder body and base wall and mucosa, urethra and corpora were isolated, frozen, and stored under liquid nitrogen. The activities of citrate synthase-thapsigargin sensitive Ca(2+) ATPase (Sarco/Endoplasmic Reticulum Ca(2+ )ATPase [SERCA]), and choline acetyl-transferase were examined as markers for mitochondrial function, sarcoplasmic reticular calcium storage and release, and cholinergic nerve function, respectively.

RESULTS

The activity of SR function indicator, Ca(2+) ATPase was significantly higher in the control corpora than in the control bladder or urethra. Castration resulted in decreased activity in the mitochondria specific enzyme, citrate synthase, the activity of which was greatest in the urethra and lowest in the corpora. Cholinergic nerve density indicator, choline acetyl-transferase activity was greatest in the bladder body and lowest in the urethra.

CONCLUSIONS

Our data indicate that (1) significant differences exist in the activities of all three enzymes in the various organs associated with the lower urinary tract; and (2) that castration results in significant alterations in the activities of all three enzymes in the bladder body, base, urethra, and corpora.

Role of Nitric Oxide in Urinary Bladder Function: Effect of L-Arginine

BACKGROUND

Evidence indicates that decreased blood flow to the bladder plays a major role in obstructive bladder dysfunction in the rabbit model of partial bladder outlet obstruction (PBOO), and that nitric oxide (NO) regulation of blood flow may be important in modulating the degree of obstructive bladder dysfunction. The specific aim of our study is to determine the effect of feeding rabbits a diet high in L-arginine on the response to PBOO.

MATERIALS AND METHODS

Sixteen male NZ White rabbits were separated into 4 groups of 4 each. The rabbits in groups 1 and 3 underwent PBOO. The rabbits in groups 2 and 4 were sham-operated. For 1 week prior to surgery, and 2 weeks postoperatively, each rabbit in groups 1 and 2 was put on a diet containing 7% arginine. Rabbits in groups 3 and 4 were on a normal diet (0.76% arginine).

RESULTS

PBOO resulted in a greater increase in bladder weight in the control group than the arginine group. PBOO resulted in a greater decrease in compliance in the control group than the arginine group. The contractile responses to all agents in the arginine control group were greater than in the control normal diet group. PBOO resulted in a greater decrease in the response to field stimulation in the control group than in the arginine group.

CONCLUSIONS

These studies clearly demonstrate that feeding rabbits a diet high in L-arginine was beneficial for the control rabbits, and reduced the level of dysfunctions following PBOO.

Long term partial bladder outlet obstruction induced contractile dysfunction in male rabbits: A role for Rho-kinase

AIMS

In this study we examined the expression of Rho-kinase (ROK) isoforms in rabbit detrusor smooth muscle during the progression of partial bladder outlet obstruction and correlated them with the time course of obstruction.

METHODS

Detrusor samples were obtained from bladders after 1, 2, 4, and 8 weeks of obstruction and also sham operated control rabbits. Contractile responses to field stimulation (FS) and also the smooth muscle (SM) to collagen ratio were determined in isolated bladder strips. Reverse transcriptase-polymerase chain reaction, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting were used to determine the relative levels of ROK isoform expression at the mRNA and protein levels.

RESULTS

Bladder weight increased gradually and contractile responses were reduced significantly over the course of obstruction. The smooth muscle/collagen ratio increased significantly during the course of obstruction. The expression of ROKalpha increased significantly to approximately the same extent in 1-4-week obstructed groups and increased further in the 8-week obstructed group, both at the mRNA and protein levels. In contrast, there was a significant decrease in the expression of ROKbeta in the obstructed groups, which gradually decrease during the course of 1-4-week obstruction period and are slightly upregulated at the decompensated stage at 8-week obstruction.

CONCLUSIONS

The change in the isoforms of ROK may be part of the molecular mechanism for bladder compensation following partial bladder outlet obstruction.

Effects of a vitamin D(3) analogue in a rat model of bladder outlet obstruction

OBJECTIVES

To explore the effect of the vitamin D3 analogue, BXL-628, on some of the consequences of bladder outlet obstruction (BOO), e.g. hypertrophy and loss of contractile function, as vitamin D3 and BXL-628 inhibit prostate and bladder cell growth in vitro, and there are receptors for vitamin D in rat and human bladder.

MATERIAL AND METHODS

In female rats, BOO was produced by a standardized method; one group received daily BXL-628 (150 microg/kg per day) and the remaining rats received vehicle. Sham-operated rats received BXL-628 or vehicle. After 2 weeks, the conscious rats were assessed by cystometry. Plasma calcium levels were determined and in vitro contractility assessed at the end of the experiments.

RESULTS

There was a significant increase in bladder weight, micturition interval and volume, and in bladder capacity in both the obstructed groups compared to sham controls, but no difference between the obstructed groups. On plotting the micturition pressure against bladder weight within the obstructed groups, there was a clear correlation in the vehicle-treated group, indicating a decrease in contractile function with increasing bladder weight. There was no such correlation in the treatment group. In vitro, there was a strong correlation of increasing bladder weights vs decrease in response to KCl and electrical-field stimulation in strips from obstructed vehicle-treated rats, but no correlation in those from drug-treated rats. Treatment increased the plasma calcium level by 12%.

CONCLUSIONS

The vitamin D(3) analogue used did not prevent bladder hypertrophy, but appeared to reduce some of the negative functional changes of the bladder smooth muscle, which occurs with BOO-induced increases in bladder weight.

Effect of tamsulosin on spontaneous bladder contraction in conscious rats with bladder outlet obstruction: Comparison with effect on intraurethral pressure

We investigated the effect of tamsulosin, an alpha(1)-adrenoceptor antagonist, on bladder function, especially spontaneous bladder contractions before micturition (premicturition contraction), in conscious rats with bladder outlet obstruction induced by partial urethral ligation, and compared the results with the effect on intraurethral pressure response in anesthetized rats. In obstructed rats, the alpha(1)-adrenoceptor antagonists tamsulosin, naftopidil and urapidil and non-selective alpha-adrenoceptor antagonist phentolamine inhibited premicturition contractions in a dose-dependent fashion. In contrast, yohimbine, an alpha(2)-adrenoceptor antagonist, and atropine, a muscarinic receptor antagonist, hardly inhibited them. Tamsulosin and urapidil showed clearly inhibitory effects on increases in intraurethral pressure induced by phenylephrine, an alpha(1)-adrenoceptor agonist, in the same dose range as that at which they inhibited premicturition contractions, whereas naftopidil required somewhat higher doses to inhibit increases in intraurethral pressure than those at which it inhibited premicturition contractions. In conclusion, premicturition contractions observed in obstructed rats were sensitive to alpha(1)-adrenoceptor antagonists, but not to alpha(2)-adrenoceptor or muscarinic receptor antagonists. Tamsulosin was shown to be effective against both premicturition contraction and intraurethral pressure response in the same dose range in rats. These results partly support the fact that tamsulosin has improved storage symptoms as well as voiding symptoms in patients with lower urinary tract symptoms associated with bladder outlet obstruction by blocking alpha(1)-adrenoceptors.

Pre-clinical evidence and clinical translation of benign prostatic hyperplasia treatment by the vitamin D receptor agonist BXL-628 (Elocalcitol)

The active form of vitamin D, 1,25-dihydroxyvitamin D3, is a secosteroid hormone that binds to the vitamin D receptor (VDR), a member of the superfamily of nuclear receptors, and exerts a number of diverse biological functions. The natural hormone and synthetic VDR agonists are well known for their capacity to control calcium and bone metabolism, but they also regulate proliferation and differentiation of many cell types, and possess exquisite immunoregulatory properties, mostly by targeting dendritic cells (DC) and T cells. These properties have been clinically exploited in the treatment of different diseases, from secondary hyperparathyroidism to osteoporosis to psoriasis. The VDR is expressed by most cell types, including cells of the urogenital system such as prostate and bladder cells. In particular, the prostate has been recognized as a target organ of VDR agonists and represents an extra-renal synthesis site of 1,25-dihydroxyvitamin D3, but its capacity to respond to VDR agonists has, so far, been probed only for the treatment of prostate cancer. We have taken a different approach, and have analysed the capacity of VDR agonists to treat benign prostatic hyperplasia (BPH), a complex syndrome characterized by a static component related to prostate overgrowth, a dynamic component responsible for urinary irritative symptoms, and a possible inflammatory component. Pre-clinical data reviewed here demonstrate that VDR agonists, and notably BXL-628 (Elocalcitol), reduce the static component of BPH by inhibiting the activity of intra-prostatic growth factors downstream of the androgen receptor, and the dynamic component by targeting bladder cells. These data have led to a proof-of-concept clinical study that has successfully shown arrest of prostate growth in BPH patients treated with BXL-628. Ongoing clinical studies will assess the capacity of this VDR agonist to reduce symptoms and ameliorate flow parameters in BPH-affected individuals. The pronounced effects of BXL-628 on bladder smooth muscle cells and its anti-inflammatory properties indeed anticipate beneficial effects also on BPH-related lower urinary tract symptoms.

Investigation of early protein changes in the urinary bladder following partial bladder outlet obstruction by proteomic approach

We investigated the pathophysiological mechanism by proteomic approach as a possible tool to detect the marker proteins to develop lower urinary tract symptoms following bladder outlet obstruction (BOO). Rats were randomized into 3 groups; control, sham operation and BOO groups. BOO group was divided into 1, 3, and 5 day-group. Conventional proteomics was performed with high resolution 2-D gel electrophoresis followed by computational image analysis and protein identification using mass spectrometry using rat urinary bladders. A comparison of bladder of BOO group with control bladder showed that three proteins of optineurin, thioredoxin and preprohaptoglobin were over-expressed in the bladder of BOO group. In addition, four proteins, such as peroxiredoxin 2, transgelin, hippocampal cholinergic neurostimulating peptide (HCNP) and beta-galactoside-binding lectin, were under-expressed in the bladder of BOO group. These data supported that downregulation of HCNP might make detrusor muscle be supersensitive to acetylcholine, up-regulation of optineurin means the protection of nerve injury, and down-regulation of transgelin means the decreased contractility of detrusor muscle. Beside these proteins, other proteins are related to oxidative stress or have a nonspecific function in this study. However more information is needed in human bladder tissue for clinical usage.

Fact or fiction: what do the benign prostatic hyperplasia data tell us?

Benign prostatic hyperplasia (BPH) is the most common benign neoplasm in men. Our understanding of this condition has improved greatly over the years and recent advances have changed our approach to management. At the end of the 19th century, prostatic enlargement was treated effectively by bilateral orchidectomy. Unsurprisingly, this treatment option never gained widespread popularity. Less than 10 years ago, surgery and watchful waiting were the only considered treatment options for BPH. We now have a number of medical therapies and minimally invasive treatment options available that can effectively manage lower urinary tract symptoms secondary to benign prostatic obstruction. However, with increased choice comes the increased need for clarity in selection and application of these various treatment options. In the current environment of evidence-based clinical practice, awareness and interpretation of data from the numerous studies is paramount. The lessons learned from these trials should be reflected clearly in our practice, with clinical management based on fact, not fiction. In this review, we critically assess the available data and understanding of the management of BPH.

Protection of urinary bladder function by grape suspension

Urinary bladder dysfunction secondary to BPH is a major affliction of aging men. A rabbit model of partial outlet obstruction was used to evaluate the ability of a standardized grape suspension to protect the bladder against obstructive bladder dysfunction.Twenty-four New Zealand White rabbits were separated into four groups of six rabbits each. Groups 1 and 3 were pretreated by oral gavage for 3 weeks with a standardized grape suspension suspended in water; groups 2 and 4 were treated with vehicle. Groups 1 and 3 received sham operations after 3 weeks of treatment; groups 2 and 4 received partial outlet obstruction by surgically placing a silk ligature loosely around the urethra. At 3 weeks following surgery, in vivo and in vitro bladder functions were evaluated. Based on both in vivo and in vitro studies, the grape suspension significantly reduced the severity of obstructed bladder dysfunction. This is consistent with the hypothesis that ischemia is a major etiological factor in obstructive dysfunction, and treatment with antioxidants and membrane stabilization compounds such as those in the grape suspension can be effective in the treatment of obstructive bladder pathology.

Inhibitory effect of buflomedil on prostate alpha1A adrenoceptor in the Wistar rat

The inhibitory effect of buflomedil on alpha1A-adrenoceptor (AR) in the prostate of Wistar rat was investigated in this study. Normotensive and spontaneous hypertensive rats were orally fed with buflomedil (150 mg/kg). The drug effects on blood pressure and heart rate were monitored by photoelectric volume oscillometric method. Prostate tissue strips from normotensive rats were contracted in vitro in organ bath by phenylephrine (10(-8) to 10(-2)M). The inhibitory effects of buflomedil (10(-9) to 10(-7)M) on the phenylephrine-induced contractions were measured. Radioligand binding displacement study by buflomedil was performed on rat prostate alpha1A-adrenoceptor (AR) and spleen alpha1B-AR. Furthermore the effects of buflomedil and WB-4101 on phenylephrine (10 microM) activated uptake of 2-[14C]-deoxy-d-glucose (2-DG) into C2C12 cells were evaluated. The results showed that buflomedil feeding did not alter the systolic blood pressure of either spontaneous hypertensive rats or normal rats. Dose-inhibition curves of phenylephrine-induced prostate contraction demonstrated a higher potency of buflomedil than tamsulosin. Buflomedil displaced [3H]prazosin binding in a concentration-dependent manner both in rat prostate alpha1A-AR and spleen alpha1B-AR. The ratio of affinity to alpha1A-AR and alpha1B-AR for buflomedil was 4.06/6.84, indicating selectivity on alpha1A-AR over alpha1B-AR. Activation of C2C12 cell alpha1A-AR by phenylephrine increased the glucose uptake to 116%. Both buflomedil and WB-4101 inhibited the uptake in a concentration-dependent manner. In conclusion, the findings showed that buflomedil has preferential alpha1A-AR antagonistic effect to inhibit prostate contraction without significantly affecting the blood pressure.

THE MOLECULAR GENETIC BASIS OF MITOCHONDRIAL MALFUNCTION IN BLADDER TISSUE FOLLOWING OUTLET OBSTRUCTION

PURPOSE

Bladder dysfunction following partial outlet obstruction is a frequent consequence of benign prostatic hyperplasia and an increasingly common problem given the aging of the general population. Recent studies from this and other groups have begun to elucidate the molecular bases for the well described physiological malfunctions that characterize this clinical entity. We summarized and synthesized that information.

MATERIALS AND METHODS

Using modern methods of molecular genetics, including real-time polymerase chain reaction, real-time reverse transcriptase-polymerase chain reaction and others, as well as traditional experimental techniques such as electron microscopy we and others examined the transcriptional profile, morphology, etc of bladder smooth muscle mitochondria in experimental models of outlet obstruction.

RESULTS

Data from many studies have demonstrated that aberrant gene expression in the mitochondrial and mitochondria related nuclear genetic systems underlies the loss of compliance and other attributes of bladder dysfunction following outlet obstruction. Such aberrant transcriptional characteristics engender loss of function in the electron transport and oxidative phosphorylation systems. Morphological studies of mitochondria in the animal model systems support this conclusion.

CONCLUSIONS

In large part the loss of function in bladder smooth muscle following outlet obstruction results from the attenuation of mitochondrial energy production. In this article we reviewed and synthesized all available experimental observations relevant to this problem and we suggest future lines of inquiry that should prove fruitful in developing new strategies to treat the condition.

Lower urinary tract symptoms/benign prostatic hyperplasia: maintaining symptom control and reducing complications

Because the average patient with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH), or LUTS/BPH, has a remaining life expectancy of 15 to 20 years, both short-term and long-term outcomes matter in the management of LUTS/BPH. Sustained symptom control and improvement of quality of life (QOL), control of disease progression (ie, prevention or reduction of bladder wall hypertrophy [BWH]/increased bladder mass and reduction of the risk of serious complications), and minimization of the need to switch to other medical therapy or surgery are important. In this respect, alpha(1)-adrenoceptor antagonists, such as tamsulosin, have been shown to provide effective and rapid relief of symptoms and improvement in QOL, which is sustained in the long term (up to 6 years). Obstruction may, in the long term, induce changes in the bladder wall (eg, BWH), which may result in (irreversible) bladder damage and serious complications. Preliminary data suggest that alpha(1)-adrenoceptor antagonists prevent the development of BWH in rabbits and reduce existing BWH in obstructed LUTS/BPH patients. Pooled analyses and indirect comparisons of clinical studies up to 1 year have shown that alpha(1)-adrenoceptor antagonists, such as tamsulosin, reduce the risk of acute urinary retention and the need for surgery to at least the same extent as the 5alpha-reductase inhibitor finasteride. In addition, monotherapy with an alpha(1)-adrenoceptor antagonist reduces the risk of long-term clinical progression; the combination with finasteride may be more beneficial in patients at high risk (patients with large prostate volume, high level of prostate-specific antigen, high International Prostate Symptom Score, high postvoid residual amount, and low maximum flow rate). Therefore, alpha(1)-adrenoceptor antagonists, such as tamsulosin, are first-line therapy, not only in the short term but also in the long-term management of LUTS/BPH.