Molecular and Morphological Characteristics of the De-Obstructed Rat Urinary Bladder-An Update.

Many patients with outlet obstruction secondary to prostatic enlargement have lower urinary tract symptoms (LUTSs) and an increased frequency of micturition. The standard treatment is transurethral resection of the prostate (TURP), which alleviates obstruction and symptoms. However, after TURP, 20-40 percent of patients continue to experience LUTSs. The aim of the present study in rats was to identify the mechanisms that do not normalize after the removal of the obstruction and that could explain the persisting symptoms. We had microarray data from control, obstructed, and de-obstructed female rat bladders, which made it possible to study 14,553 mRNA expressions. We also had a bank of electron micrographs from similar detrusors. Microarrays: There were significant differences between the control and obstructed bladders for 1111 mRNAs. The obstructed and de-obstructed bladders differed significantly for 1059 mRNAs. The controls and the de-obstructed bladders differed significantly for 798 mRNAs. We observed many mRNAs that were increased in the obstructed bladder and then decreased to control levels after de-obstruction, and many mRNAs that were decreased in the obstructed bladder and then increased following de-obstruction. mRNAs that were significantly higher or lower in the de-obstructed bladder than in the control bladder were also found. Ultrastructure: The detrusor cells in the obstructed bladders had cross-sectional areas that were much larger than those in the controls. The control cells had smooth outlines and similar cross-sectional areas. The de-obstructed detrusor cells had larger cross-sectional areas than the controls, as well as corrugated surfaces. The cell areas varied, suggesting that the shrinkage of the de-obstructed cells was not even. We did not find any points of contact of the gap junction plaque type between the detrusor cells. There were abundant finger-like processes between the detrusor cells in the obstructed and in de-obstructed bladders, which were only occasionally found in the control detrusors. They are the only possible localization for gap junction channels. The de-obstructed rat bladder is not an organ with properties intermediate between those of the control and obstructed bladders. Instead, de-obstructed bladders have gene expressions, morphologies, and functional properties of the individual cells and their organization, which make them distinctly different from both control and obstructed bladders.

Suppression of Oxidative Stress of Modified Gongjin-Dan (WSY-1075) in Detrusor Underactivity Rat Model Bladder Outlet Induced by Obstruction.

OBJECTIVE: To investigate the anti-oxidative stress and preventive effect of modified Gongjin-dan (WSY-1075) in a detrusor underactivity rat model. METHODS: Rats were randomly allocated to three groups: shamoperated (control), bladder outlet obstruction-induced detrusor underactivity (BOO-DU), and BOO-DU with WSY-1075 (WSY) groups. WSY-1075 was orally administrated to rats 200 mg daily for 2 weeks prior to the operation and 4 weeks after the operation. Bladder outlet obstruction was surgically induced in rats by ligation around the urethra avoiding total obstruction. Cystometrography was conducted on rats in each group for examination of bladders. RESULTS: Compared with the control group, bladder outlet obstruction led to a significant increase in oxidative stress with consequent changes to molecular composition, and decrease in maximal detrusor pressure (P<0.05). WSY-1075 treatment significantly suppressed oxidative stress and prevented degenerative and dysfunctional changes in bladder, as compared with BOO-DU group (P<0.05). CONCLUSION: WSY-1075 had beneficial effect on prevention of BOO-DU.

The Obstructed Bladder: Expression of Collagen, Matrix Metalloproteinases, Muscarinic Receptors, and Angiogenic and Neurotrophic Factors in Patients With Benign Prostatic Hyperplasia.

OBJECTIVE: To evaluate the gene expression of collagen, matrix metalloproteinases (MMPs) and inhibitors, cholinergic muscarinic receptors (CHRMs), and angiogenic and nerve growth factors (NGFs) in the bladder of patients with bladder outlet obstruction caused by benign prostatic hyperplasia (BPH). METHODS: We analyzed bladder specimens from 43 patients with obstructive BPH undergoing transurethral resection of the prostate as compared to 10 age-matched controls with an International Prostatic Symptom Score of <8 and a prostate volume of <30 g. A bladder biopsy was performed for relative gene expression analysis with quantitative real-time polymerase chain reaction of collagens I and III, MMP-1, MMP-2, and MMP-9; tissue inhibitors of metalloproteinases (TIMPs) TIMP-1, TIMP-2, and reversion-inducing cysteine-rich protein with kazal motifs (RECK); CHRM2 and CHRM3; VEGF and CD105; and NGF and nerve growth factor receptor (NGFr). RESULTS: Patients with bladder outlet obstruction presented a statistically significant overexpression of collagens I and III, VEGF, CHRM2, and CHRM3. CD105, MMP-9, and TIMP-1 were underexpressed. Expressions of NGF, NGFr, MMP-1, MMP-2, TIMP-2, and RECK were heterogeneous. CHRM2 and CHRM3 were overexpressed in patients with persistent detrusor overactivity. Smokers presented an upregulation of NGFr and VEGF; dyslipidemic patients had an overexpression of NGFr. CONCLUSION: Bladder upregulation of collagens I and III on transcriptional level appears to be relevant in BPH. Muscarinic receptors CHRM2 and CHRM3 are also overexpressed, more so in patients with persistent detrusor overactivity. Upregulation of VEGF and NGFr, particularly in subjects with risk factors for atherosclerosis, reinforces the role of ischemia in BPH-induced modifications of the bladder.

Preventive Effect of Hydrogen Water on the Development of Detrusor Overactivity in a Rat Model of Bladder Outlet Obstruction.

PURPOSE: Bladder ischemia and oxidative stress contribute to the pathogenesis of bladder dysfunction caused by bladder outlet obstruction. H2 reportedly acts as an effective antioxidant. We investigated whether oral ingestion of H2 water would have a beneficial effect on bladder function in a rat model of bladder outlet obstruction. MATERIALS AND METHODS: H2 water was made by dissolving H2 gas in ordinary drinking water using a hydrogen water producing apparatus. The bladder outlet obstruction model was surgically induced in male rats. Rats with obstruction were fed H2 water or ordinary drinking water. On week 4 postoperatively cystometry was performed. Oxidative stress markers and the bladder nerve growth factor level were determined. Bladder tissues were processed for pharmacological studies and histological analysis. RESULTS: The micturition interval and micturition volume significantly decreased in obstructed rats given ordinary drinking water. These decreases were significantly suppressed by oral ingestion of H2 water. Increased post-void residual volume in obstructed rats was significantly reduced by H2 water. Obstruction led to a significant increase in bladder weight, oxidative stress markers and nerve growth factor. H2 water significantly suppressed these increases without affecting bladder weight. There was no significant difference in histological findings between rats with bladder obstruction given H2 water and ordinary drinking water. Decreased responses of detrusor muscle strips from obstructed bladders to KCl, carbachol and electrical field stimulation were reversed by H2 water ingestion. CONCLUSIONS: Results suggest that H2 water could ameliorate bladder dysfunction secondary to bladder outlet obstruction by attenuating oxidative stress.

Effect of the Chinese traditional prescription Suo Quan Wan on TRPV1 expression in the bladder of rats with bladder outlet obstruction.

BACKGROUND: Suo Quan Wan (SQW) is a Chinese traditional prescription that has been used in clinical treatment of lower urinary tract symptoms for centuries. However, scientific basis of SQW efficacy and mechanism is still needed. This study investigated the effect of SQW on bladder function and transient receptor potential vanilloid 1 (TRPV1) expression in the bladder of rats with bladder outlet obstruction (BOO). The induced changes in bladder function in overactive bladder (OAB) rat model were observed following different periods of outlet obstruction to obtain an appropriate rat model. METHODS: This study was carried out in two parts. In the first part, female Sprague-Dawley rats received sham operations or partial BOO operations. Two, four, and six weeks later, the OAB model groups and control were subjected to urodynamic tests to measure differences in bladder functions. Once the appropriate rat model was obtained, the second part of the experiment was performed. The rat model was recreated and treated with SQW. Urodynamic assessment was conducted, and the bladders of the rats were then removed. Immunofluorescence staining, real-time PCR, and Western blot were performed to localize and quantify the expression of TRPV1 in the bladder. RESULTS: Results of the first part indicated that at 2 and 4 weeks, the OAB model group exhibited significant differences in urodynamic parameters, including bladder pressure, maximum voiding pressure, and maximum bladder capacity, compared with the sham group. At 4 and 6 weeks, the OAB model group exhibited significant differences in residual volume (RV) and non-voiding contraction frequency. Six-week OAB model group showed much more RV but less voiding efficiency when compared with 6-week sham group or 2-and 4-week OAB model group. Rats that underwent BOO exhibited similarities with the compensated state before four weeks and may have entered decompensated state at six weeks. Studies conducted with 4-week OAB model were appropriate. In part two of the experiment, unstable bladder in the OAB model group recovered bladder stability after SQW treatment, accompanied by improved bladder hypertrophy, as well as corrected urodynamic parameters. Expression of TRPV1 mRNA and proteins in the bladder was significantly greater in the OAB model group than that in the control group, which subsequently decreased significantly with SQW treatment in BOO-induced rats. CONCLUSIONS: SQW can modulate the expression of TRPV1 in accordance with the recovery of bladder function.

Effect of ovariectomy, 17-beta estradiol, and progesterone on histology and estrogen receptors of bladder in female partial bladder outlet obstruction rat model.

AIM: The aim of this study was to investigate the effect of bilateral ovariectomy (OVX), 17-beta estradiol (E2), and progesterone (P4) on the histology and estrogen receptor (ER) expression of the bladder using a female partial bladder outlet obstruction (pBOO) rat model. MATERIAL AND METHODS: A total of 60 female Sprague-Dawley rats were evenly assigned into six groups of 10 each. Group A served as the control. Groups B-F underwent induced pBOO. Groups C-F underwent OVX. Groups D-F were given E2 (0.1 mg/kg/day), Group E was given P4 (1 mg/kg/day), and Group F was given P4 and dehydroepiandrosterone (DHEA) (300 µg/kg/day) by an Alzet pump. Four weeks later, serum E2 and P4 levels were evaluated. Each rat was anesthetized and the urinary bladder was removed for weighing and histological study. RESULTS: Expression of ER-ß was not significantly different between the control group and the other study groups. pBOO was shown to increase both bladder weight and detrusor muscle thickness. OVX had an additive effect to BOO on increased blood vessel density in the bladder. E2 was shown to increase blood vessel density, while P4 supplementation decreased blood vessel density. DHEA did not cause any significant effects on blood vessel density. CONCLUSION: Hormone therapy did not change the expression of ER in bladder outlet obstruction. Estradiol stimulated the increased angiogenesis of the bladder detrusor but P4 decreased the angiogenesis of the bladder detrusor. DHEA had no effect on the bladder detrusor.

Effect of the phytotherapeutic agent eviprostat on the bladder in a rat model of bladder overdistension/emptying.

AIMS: Ischemia-reperfusion injury is an important factor in the development of lower urinary tract symptoms (LUTS) that is partly mediated by the generation of free radicals. We investigate the effect of the phytotherapeutic agent Eviprostat, a treatment for benign prostatic hyperplasia (BPH) that has antioxidant and anti-inflammatory activity, on urinary bladder blood flow (BBF), and function in a rat model of bladder overdistension and emptying (OE). METHODS: For 8 days before surgery, OE rats received daily oral Eviprostat (36 mg/kg/day) or vehicle, while sham-operated animals received vehicle. The bladder was distended by infusion of saline over a period of 2 hr (overdistension) and then emptied. After 24 hr, BBF was measured with a laser speckle blood flow imager. The oxidative-stress marker malondialdehyde (MDA), proinflammatory cytokines, and myeloperoxidase were determined in the isolated bladder, and histological analysis was performed. Functional contractile responses of bladder strips to electrical field stimulation, carbachol, and KCl were measured. RESULTS: Twenty-four hours after bladder OE, a significant decrease in BBF and significant increases in bladder weight, malondialdehyde, proinflammatory cytokines, and myeloperoxidase were observed. Eviprostat almost completely prevented these changes. Histological analysis of the bladder of OE rats showed hemorrhage, accumulation of leukocytes, desquamation of epithelium, and edema, and Eviprostat suppressed these changes. The reduction in functional contractile forces in the bladder of OE rats was also prevented by Eviprostat. CONCLUSION: Eviprostat-mediated suppression of increased bladder oxidative stress and inflammation caused by bladder OE may contribute to the improvement of BBF and bladder function by Eviprostat.

The relaxant effect of ginseng saponin on the bladder and prostatic urethra: an in vitro and in vivo study.

AIM: To assess the effects of ginseng saponin on relaxation of the bladder and prostatic urethra and to determine its mechanism of action. MATERIALS AND METHODS: For the in vitro study, prostatic urethra muscle strips were harvested from 18 male New Zealand rabbits. The strips were mounted in organ baths and connected to force displacement transducers. After stabilization, maximal tissue contractions were obtained by the application of phenylepinephrine to the urethra strips, and a dose-response curve for ginseng saponin was constructed (10(-6)-10(-2)M). After pretreatment of urethra strips with N-nitro-L-arginine methyl ester (L-NAME), another dose-response curve for ginseng saponin was constructed. For the in vivo study, we used adult male Sprague-Dawley rats divided into three groups [control, partial bladder outlet obstruction (PBOO) and saponin-fed groups], and we monitored the vesical pressure (P(ves)) and urethral perfusion pressure (UPP). RESULTS: The ginseng saponin induced a significant dose-dependent relaxant effect on the prostatic urethra strips. A significant relaxant effect of ginseng saponin was observed from 10(-3)M, and ginseng saponin significantly relaxed urethra strips by 50.2 ± 20.26% at 10(-2)M. The relaxant effect was partially inhibited with L-NAME pretreatment. In the in vivo study, the change in UPP between baseline and relaxation was significantly higher in the saponin group than in the control or PBOO group (p < 0.001). The saponin group showed a significantly lower baseline P(ves) than the PBOO group. CONCLUSIONS: We observed a significant relaxation effect of ginseng saponin on the bladder and prostatic urethra in both in vitro and in vivo studies. The mechanism by which ginseng saponin induces relaxation appears to involve the nitric oxide/nitric oxide synthase pathway.

Suppression of bladder oxidative stress and inflammation by a phytotherapeutic agent in a rat model of partial bladder outlet obstruction.

PURPOSE: Ischemia/reperfusion injury is a major etiological factor in the progression of bladder dysfunction after partial bladder outlet obstruction and it is partly mediated by the generation of free radicals. The phytotherapeutic agent Eviprostat, a popular treatment for benign prostatic hyperplasia in Japan and Germany, has antioxidant and anti-inflammatory activity. We investigated the effect of Eviprostat on oxidative stress and inflammation in bladder dysfunction in a bladder outlet obstruction rat model. MATERIALS AND METHODS: Bladder outlet obstruction was surgically induced in male rats by placing a rubber ring around the urethra. Rats with bladder outlet obstruction were administered daily oral Eviprostat or vehicle, while sham operated animals were treated with vehicle. On day 6 after surgery bladder weight, oxidative stress markers and proinflammatory cytokine levels as a measure of bladder inflammation, were determined and histological alterations noted. Functional contractility studies were performed with longitudinal bladder strips. RESULTS: Bladder outlet obstruction led to a significant increase in bladder weight, oxidative stress markers and proinflammatory cytokine levels. Eviprostat significantly suppressed these increases without affecting bladder weight. Histological analysis showed increased detrusor muscle hypertrophy and increased numbers of collagen fibers with accompanying inflammatory infiltration in the bladder of vehicle treated bladder outlet obstruction animals. Eviprostat treatment was associated with suppression of these changes. Decreased responses of obstructed bladder strips to electrical stimulation and KCl were ameliorated by Eviprostat treatment. CONCLUSIONS: Eviprostat mediated decrease of the increased oxidative stress and bladder inflammation caused by bladder outlet obstruction may contribute to the protection of bladder function.

Estrogen administration attenuates bladder outlet obstruction induced oxidative stress in the female rabbit.

AIMS: Estrogen administration to female rabbits induces a functional hypertrophy of the bladder. The aim of this study was to investigate whether supplementation of estrogen in the female rabbit with partial bladder outlet obstruction (PBOO) would affect the severity of bladder dysfunction. METHODS: We surgically created PBOO in female New Zealand White rabbits. Group 1 included sham operated rabbits which served as controls. Group 2 received PBOO without estrogen treatment. Group 3 received estrogen treatment after PBOO. Group 4 received estrogen pretreatment before PBOO. The bladders were then removed for contractile, biochemical, and protein expression studies. There were four rabbits per group. RESULTS: (1) PBOO resulted in significant decreases in the contractile responses to all forms of stimulation (field stimulation [FS], carbachol, KCl, ATP). Both pretreatment and post-treatment with estrogen resulted in significantly increased contractile responses to all forms of stimulation, although the responses were still lower than control. (2) PBOO resulted in a significant decrease in the activity of choline acetyltransferase (ChAT). Both pretreatment and post-treatment with estrogen resulted in significant increases in ChAT activity back toward control levels. (3) PBOO resulted in significant increases in both protein oxidation and nitration; both pretreatment and post-treatment with estrogen significantly reduced oxidation and nitration toward control levels. CONCLUSIONS: Estrogen pretreatment and post-treatment in the female rabbit ameliorated contractile and biochemical dysfunctions associated with PBOO. This improvement is likely due to reduced oxidative stress. As expected, pretreatment was generally more effective than post-treatment.

Inverse expression of uroplakins and inducible nitric oxide synthase in the urothelium of patients with bladder outlet obstruction.

OBJECTIVE: To assess the expression and distribution of uroplakins, protein subunits of the asymmetric unit membrane (AUM), and inducible nitric-oxide synthase (iNOS) in the urinary bladder urothelium of patients with bladder outlet obstruction (BOO) caused by benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Urinary bladder urothelium samples from 15 men (mean age 69 years) with BOO secondary to BPH were processed for light and electron immunocytochemistry. Uroplakins and iNOS were detected, and areas of apical surface covered with AUM were compared with those of iNOS-positive urothelial cells. RESULTS: Areas of superficial urothelial cells with no AUM were found in all obstructed bladder samples. The immuno-electron microscopy showed that the uroplakin-positive cells had the characteristic appearance of terminally differentiated umbrella cells, whereas cells from the uroplakin-negative regions were undifferentiated, typically showing microvilli on their apical surface. iNOS was not detected in areas with continuous AUM staining, but was readily detected in the uroplakin-negative areas. There was an inverse correlation between the intensity of uroplakin and iNOS staining. CONCLUSIONS: In patients with BOO associated with BPH, some superficial urothelial cells lacked the AUM, suggesting focal compromise of the blood-urine permeability barrier. In such relatively undifferentiated urothelial zones there was an accompanying increase in the expression of iNOS, which marks perturbed urothelial differentiation and may modulate bladder response to the outlet obstruction.