Effect of glycine on recovery of bladder smooth muscle contractility after acute urinary retention in rats

OBJECTIVE: To investigate the effects of glycine on the recovery of bladder smooth muscle contractility after acute urinary retention. MATERIALS AND METHODS: Bladder overdistension was induced in Sprague-Dawley rats by an infusion of saline (twice the threshold volume), maintained for 2 h. From 15 min before emptying of the bladder until 2 h after, saline or glycine solution was infused i.v. At 30 min, 2 h and 1 week after bladder emptying, samples of bladder tissue were taken for muscle strip study, malondialdehyde (MDA) assay, ATP assay, Western blotting for apoptosis-related molecules (Bcl-2, Bax, Caspase-3), and histological analysis including terminal deoxynucleotidyl transferase-mediated nick-end labelling staining. The results were compared among normal control, saline-treated and glycine-treated rats. RESULTS: In the glycine-treated group, muscle strip contractile responses induced by electrical-field stimulation and carbachol were both significantly greater at 1 week after bladder emptying than in the saline-treated group. The results of the ATP assay appeared to correspond with those of the muscle strip study. The saline-treated group had significantly higher MDA levels at 30 min after bladder emptying than the glycine-treated group. At 2 h after bladder emptying, there was significantly more apoptosis and greater leukocyte infiltration in the saline-treated group than in the glycine-treated group. While pro-apoptotic Bax and caspase-3 were down-regulated, Bcl-2 was up-regulated in the glycine-treated group. CONCLUSION: Glycine infusions might improve the contractile responses of bladder smooth muscle after acute urinary retention by reducing oxidative damage and apoptosis.     

Spontaneous activity of mouse detrusor smooth muscle and the effects of the urothelium

AIMS: To characterize the detrusor muscle of the mouse urinary bladder in order to understand more precisely spontaneous contractile behavior of this organ. This study examined the spontaneous electrical activity and Ca(2+) dynamics of the detrusor smooth muscle and investigated the role of the urothelium. MATERIALS AND METHODS: Detrusor smooth muscle strips were isolated from mouse bladders. The urothelium was either kept intact or removed. Changes in membrane potential were recorded using sharp electrode intracellular recording. To image Ca(2+) dynamics, tissue strips were exposed to 10 microM Oregon Green 488 BAPTA-1 AM for 70 min, and then image series were acquired with a laser-scanning confocal microscope. RESULTS: (1) Mouse detrusor smooth muscle cells (SMCs) generate nifedipine-sensitive spontaneous action potentials (sAPs) at a low frequency (1.3 +/- 0.9 min(-1), n = 11) in preparations with intact urothelium. This frequency increased when the urothelium was removed (7 +/- 8.3 min(-1), n = 17) (P < 0.05, Student's t test). (2) Frequent ATP-mediated spontaneous depolarizations were recorded in all cells. (3) The frequency of whole cell Ca(2+) flashes of detrusor smooth muscle cells was higher in preparations with the urothelium removed (median 1.2 min(-1), n = 7) than in urothelium denuded preparations (median 0.6 min(-1), n = 7) (P < 0.01, Mann-Whitney U-test). CONCLUSIONS: Spontaneous activity of the mouse detrusor smooth muscles was characterized enabling future comparative work on gene knock-out strains. Evidence suggesting release of an inhibitory factor by the urothelium was apparent.     

Effect of cold-induced stress on rat bladder tissue contractility and histomorphology

AIMS: To investigate the effects of cold-induced stress on bladder tissue histomorphology and contractility in a rat model. METHODS: Eighteen male Sprague-Dawley rats were divided into three groups: Control group (Group 1), acute cold-stress group (Group 2, kept at +4 degrees C for 8 hr), and chronic cold-stress group (Group 3, kept at +4 degrees C for 4 hr/day for 21 days). At the end of protocols, histological examination of general bladder tissue morphology and determination of mast cells was performed. Organ bath studies were conducted at basal tone where contractile responses to 120 mM potassium, electrical field stimulation (EFS), and carbachol (10(-9)-10(-4) M) were assessed. Relaxation responses to EFS, isoproterenol (10(-9)-10(-4) M), papaverine plus sodium nitroprusside (10(-4) M each) were recorded in carbachol pre-contracted strips. All data were compared by one-way ANOVA test. RESULTS: Group 1 revealed regular bladder mucosa with intact urothelium. Groups 2 and 3 showed degeneration of urothelium with accumulation of neutrophils and significantly increased number of mast cells in both mucosa and muscularis. Mast cell counts were significantly higher in Group 3 compared to Group 2. Contractile responses to 120 mM potassium and EFS were significantly greater in the control group compared to other groups. Carbachol caused dose-dependent contractions that were significantly higher in the control group (at 10(-5), 3 x 10(-5), and 10(-4) M doses). There was no statistical difference between the groups in terms of relaxation responses. CONCLUSIONS: In vivo cold exposure induces significant bladder injury and decreased tissue contractility. Mechanistic pathways involved in the response of the urinary bladder to cold-induced stress need further investigation.     

Further experience with seromuscular colocystoplasty lined with urothelium

PURPOSE: We report our continuing experience with seromuscular colocystoplasty lined with urothelium. This procedure is designed to preserve the urothelium and potentially decrease the incidence of complications associated with standard bladder augmentation. MATERIALS AND METHODS: We retrospectively reviewed the charts of 32 patients who underwent seromuscular colocystoplasty lined with urothelium between April 1994 and July 1999. Data were collected on patient demographics, surgical indications, previous and adjunctive surgical procedures, preoperative and postoperative urinary continence, upper urinary tract changes, urodynamic parameters, surgical complications and histological findings. RESULTS: Mean patient age at surgery plus or minus standard deviation was 11.1 +/- 4.8 years. Mean followup was 1.6 +/- 1 years. A mean of 1.5 +/- 0.9 years postoperatively urodynamic studies available in 28 cases showed that total and safe bladder capacity increased by 1.8 and 2.4-fold, respectively. Continence was achieved in 71% of patients after the initial procedure, increasing to 81% after secondary procedures. Hourglass deformity developed in 7 cases (22%), augmentation failed in 4 (12.5%) and there were bladder calculi in 2 (6%). New onset or increased hydronephrosis and reflux were present in 6 of 62 (10%) and 9 of 60 (15%) evaluated renal units, respectively. Of the 7 interpretable biopsies 5 revealed various degrees of repeat colonic mucosal growth. There was no bladder perforation or metabolic abnormalities, and mucous production was not clinically significant. CONCLUSIONS: Seromuscular colocystoplasty lined with urothelium is a viable alternative to standard bladder augmentation. The 2 procedures have a similar overall complication rate. Comparatively there appears to be a low incidence of bladder calculi, mucous production has not been clinically significant, metabolic disturbances have not developed and perforation has not occurred during short-term followup. We are enthusiastic about this technique and continue to apply it in select patients.     

Urinary bladder bilharziasis as a cause of impaired bladder muscle contractility

In an attempt to evaluate the effect of bilharziasis on bladder contractility as a factor in the genesis of voiding disorders, 44 cases of bilharzial bladder neck obstruction diagnosed using traditional methods (symptomatological, radiographic, and endoscopic) were subjected to complete urodynamic evaluation (flowmetry, cystometry, pressure/flow study, and stop-flow test). Their parameters were compared with those of 28 patients with urodynamically obstructed benign prostatic hyperplasia and 8 nonsymptomatic controls. Contractility parameters (isometric detrusor pressure, maximum estimated flow rate, detrusor power at maximum flow) were calculated for the studied cases and their distribution according to the Schafer pressure/flow diagram was evaluated. Bladder biopsy including the detrusor was evaluated in all 72 patients. Poor bladder contractility associated with an extensive bilharzial effect on the detrusor muscle was found to be the major abnormality in 20 of 44 patients with presumed bilharzial bladder neck obstruction with no evidence of urodynamic outflow obstruction. We believe such a workup is essential in cases of suspected obstruction associated with bilharziasis to throw light on the pathophysiology of the voiding disorders, avoid unnecessary surgery, and provide a better prognosis. Neurourol. Urodynam. 17:483–492, 1998. © 1998 Wiley-Liss, Inc.     

DNA damage repair in bladder urothelium after the Chernobyl accident in Ukraine

PURPOSE: We determined whether base and nucleotide excision repair is activated in bladder urothelium by chronic persistent low doses of ionizing radiation in male patients with benign prostate hyperplasia and females with chronic cystitis living more than 15 years in Cs contaminated areas after the Chernobyl accident in Ukraine. MATERIALS AND METHODS: Bladder urothelial biopsies from 204 patients were subjected to histological examination and biopsies from 35 were subjected to immunohistochemical study of 8-hydroxy-2'deoxyguanosine, 8-oxoguanine-DNA-glycosylase, apurinic/apyrimidinic endonuclease and xeroderma pigmentosum A endonuclease. RESULTS: Chronic proliferative atypical cystitis with multiple foci of dysplasia and carcinoma in situ were observed in 139 (89%) and in 91 (58%) of 156 group 1 patients from radio contaminated areas, respectively, as well as 10 small transitional cell carcinomas. Chronic cystitis with areas of dysplasia was detected in 9 of 48 patients (19%) in control group 2 from clean (without radio contamination) areas of Ukraine. Greatly elevated levels of 8-hydroxy-2'deoxyguanosine, 8-oxoguanine-DNA-glycosylase, apurinic/apyrimidinic endonuclease and xeroderma pigmentosum A were evident in the urothelium in group 1, accompanied by increased Cs in the urine. CONCLUSIONS: These findings support the hypothesis that significant activation of DNA damage repair (base and nucleotide excision repair) is induced by the oxidative stress generated by long-term low doses of ionizing radiation. The levels of DNA oxidative adducts pointing to mutagenic and carcinogenic potential were in line with the histopathologically diagnosed urothelial lesions.     

Effects of cold storage on the function and morphology of isolated urinary bladder in rat

AIMS: We investigated the effects of 24- and 48-hr storage at 4 degrees C in Krebs solution on the function and morphology of isolated, rat urinary bladders. METHODS: Strips of bladder were obtained from eight male Sprague-Dawley rats. Six strips were harvested from each bladder and randomized to storage for 24 or 48 hr at 4 degrees C in Krebs solution or examination immediately after harvest. Contractile responses of the strips to potassium chloride (KCl), electric field stimulation (EFS), adenosine 5'-triphosphate (ATP) and carbamylcholine (CCh) were assessed. Histological examination of the bladder strips was performed. The pO(2), pCO(2), and pH of the solution in each storage container were measured at each storage time point. RESULTS: Cold storage induced a significant decrease in the amplitude of contraction in response to KCl and EFS after 24 or 48 hr of storage compared with control. The response of the bladder strips to ATP and CCh was significantly reduced after 48-hr storage compared with control, but not 24-hr storage. The pO(2) and pCO(2) decreased after cold storage. The pH increased after 24 hr of storage and remained stable between 24 and 48 hr of storage. Histological evaluation of the strips showed tissue swelling after 24 and 48 hr of storage. CONCLUSIONS: These results suggest that the morphology and function of bladder strips stored for 24 to 48 hr at 4 degrees C in Krebs solution undergo significant changes. Further studies are needed to assess the allowable time for storage of bladder tissue.     

Detrusor contractility and overactive bladder in patients with cerebrovascular accident

Objectives:   A retrospective analysis of urodynamic studies was conducted to investigate detrusor contractility following cerebrovascular accident.
Methods:   Fifty-seven patients (34 men and 23 women) who were rehabilitated following cerebrovascular accident were included in the analysis. Subjects with maximum contractile power values less than 10 W/m² in men and 8 W/m² in women, in the absence of bladder outlet obstruction, were defined as having detrusor underactivity.
Results:   A significantly lower maximum value of detrusor contractile power and a larger residual urine volume, particularly more prevalent in women than in men, appeared unexpectedly after cerebrovascular accident. Patients with underactivity had significantly lower maximum and average flow rates, lower contractile power, and an increased postvoid residual relative to their normal counterparts. The prevalence of underactivity was 35% in the men and 43% in the women. Furthermore, 67% of the men and 80% of the women with underactivity had overactive bladder symptoms. On the other hand, detrusor underactivity was observed in 8 (35%) of 23 overactive bladder patients in the men and 8 (42%) of 19 in the women.
Conclusions:   Post-cerebrovascular accident patients presented various patterns of detrusor contractility. Specific attention to the possible occurrence of detrusor underactivity in these patients is essential for the successful management of overactive bladder syndrome.     

Muscarinic and purinergic receptor expression in the urothelium of rats with detrusor overactivity induced by bladder outlet obstruction

OBJECTIVE

To investigate the expression of muscarinic and purinergic receptors in rat urothelium, and changes in their distribution and expression following detrusor overactivity induced by bladder outlet obstruction (BOO).

MATERIALS AND METHODS

Thirty Sprague‐Dawley rats were divided into control (10) and BOO groups (20). Partial BOO was induced for 3 weeks and the rats assessed by cystometrography. A portion of the bladder was stained using immunofluorescence for M₂ and M₃ muscarinic receptors, and P2X₃ purinergic receptors. The remainder was dissected into bladder urothelium and the smooth muscle layer, and the expression of the receptor proteins analysed by Western blotting.

RESULTS

Cystometrography showed a significant decrease in contraction interval and increase in contraction pressure in the BOO group. On immunofluorescence staining, muscarinic and purinergic receptors were localized in both the urothelium and the muscle layer. Immunoreactivity of M₂ and M₃ muscarinic receptors was greater in the urothelium of the BOO group than in the control group; there was a smaller increase in P2X₃ immunoreactivity. On Western blotting, the expression of M₂, M₃ and P2X₃ receptors was increased in the urothelium of the BOO group, and there was increased M₃ receptor expression in the muscle layer of the BOO group.

CONCLUSIONS

There were detectable changes in muscarinic and purinergic receptors with bladder overactivity induced by BOO. Our results suggest that changes in urothelium receptor expression could have a role in mediating the afferent sensory responses in the urinary bladder.     

Role of sorbitol in the up-regulation of urinary bladder M(2) muscarinic receptors in streptozotocin-induced diabetic rats

This study investigated the role of sorbitol, a metabolic product of glucose, in the pathogenesis of rat diabetic cystopathy. Three-month-old male Wistar rats were divided into four groups: 1) normal controls; 2) rats rendered diabetic by streptozotocin; 3) rats fed with glucose; and 4) rats injected with sorbitol. The M(2) muscarinic receptor (M(2)-mAChR) protein and mRNA densities of the bladder tissue were measured by Western immunoblot and Northern blot, respectively. The streptozotocin-induced diabetic rats were then treated with ONO-2235, an aldose reductase inhibitor. The bladder M(2)-mAChR protein and mRNA were compared between the treated and untreated diabetic rats. The densities of M(2)-mAChR protein and mRNA in the bladder tissue were significantly increased in diabetic rats, and rats given either glucose or sorbitol (increases in receptor protein: 27.3 +/- 3.3, 19.8 +/- 2.3, and 18.0 +/- 2.1%; increases in mRNA: 39.6 +/- 3.7, 33.1 +/- 2.9, and 20.2 +/- 2.2%, respectively). When diabetic rats were treated with ONO-2235, the increases in bladder M(2)-mAChR protein and mRNA were significantly alleviated. The findings suggest that sorbitol plays a role in the pathogenesis of diabetic cystopathy in rats rendered diabetic by streptozotocin. Aldose reductase inhibitors may be useful in the treatment and prevention of diabetic cystopathy.     

Effect of cromakalim on micturition function in rats

Although many studies investigating the effect of cromakalim on bladder contractility exist, thus far, there are no published studies investigating its effect on micturition function in conscious rats. We measured the effect of cromakalim i.v. on urine output, frequency, volume of each micturition, and blood pressure in saline-diuresed and non-diuresed rats. In saline-diuresed rats cromakalim produced significant decreases in urine output (0.1 mg/kg, 32%; 0.3 mg/kg, 46%; 1.0 mg/kg, 68%) and average frequency (0.1 mg/kg, 36%; 0.3 mg/kg, 51%; 1.0 mg/kg, 70%) in the first 3 hours. At 3–6 hours after administration of cromakalim there were rebound increases in both urine output (0.1 mg/kg, 290%; 0.3 mg/kg, 373%; 1.0 mg/kg, 538%), and frequency (0.1 mg/kg, 147%; 0.3 mg/kg, 181%; 1.0 mg/kg, 314%) and by 6–12 hours the effects of cromakalim on micturition function were gone. Mean arterial pressure dropped to 50% of control immediately after cromakalim administration in saline-diuresed rats and began to return to control levels after 3 hours. Cromakalim produced similar results in non-diuresed rats. The decrease in urine output 0–3 hours after cromakalim administration may have been a consequence of cromakalim's profound decrease in blood pressure that occurred during that time. © 1993 Wiley-Liss, Inc.     

Effects of acid-base changes on rabbit urinary bladder contractility

Alterations in the pH of the in vitro bathing medium can effect intracellular pH and thus alter the contractile response of smooth muscle preparations to various forms of stimulation. The mucosal surface of the urinary bladder provides a barrier to most solutes within the bladder. The purpose of this study was to determine if alterations in the intravesical pH would affect the contractile response to field stimulation. The in vitro whole rabbit bladder model was used to study the effect of changing intravesical pH on bladder contractility. Contrary to previous studies on isolated muscle strips, the results of the present study show that under different pH conditions (pH 4.0–8.0), no significant changes were observed in intravesical pressure generation with field stimulation, nor in the rate of the pressure generation. An intact bladder mucosa appears to be an effective barrier against the physiological effects of altered intravesical pH on bladder smooth muscle contraction.     

Clinical panurothelial disease in patients with superficial bladder tumors: therapeutic implications

PURPOSE: We established the prognostic and therapeutic implications of panurothelial involvement in patients with superficial bladder tumors for optimizing therapeutic approaches in those at risk for panurothelial involvement. MATERIALS AND METHODS: We studied the records of 35 patients with clinical panurothelial disease. Since all of these patients presented with high risk superficial bladder cancer during followup, they were included in specific therapeutic and followup regimens. Radical procedures or conservative therapies were indicated mainly according to pathological examination and the recurrence pattern. RESULTS: Panurothelial involvement was a late stage of a recurrent and diffuse process that essentially developed in sequences, in which all patients presented with high risk superficial bladder tumors. This process involved continued relapse after panurothelial involvement developed. Notably 19 patients (79.1%) at risk for recurrence had repeat relapse in the urothelium. In the upper urinary tract 12 patients (34.3%) had bilateral involvement, including 7 (41.2%) of 17 patients after cystectomy. We identified 2 subgroups of patients. The subgroup with a better prognosis included 27 patients in whom late panurothelial disease developed step by step after a complete response to intravesical therapy, including 14 (51.8%) who were free of disease. The other subgroup with a poor prognosis included 8 patients with concurrent bladder carcinoma in situ and prostate involvement as well as early panurothelial disease, of whom only 2 (25%) were disease-free. All patients underwent many therapeutic approaches. A mean of 7.5 surgical procedures per patient were done, including a mean of 5.5 transurethral resections, a mean of 1 conservative approach to the upper urinary tract and a mean of 1.1 radical procedures. At a median followup of 111 months 10 patients (28.5%) were disease-free but only 7 (20%) retained the bladder, while 19 (54.3%) died of tumor. CONCLUSIONS: Patients with high risk superficial bladder multifocal tumors and associated bladder carcinoma in situ are at high risk for panurothelial involvement. Radical cystectomy may be recommended in these patients when initially or during followup, concurrent high risk superficial bladder tumors and prostate involvement develop or prostate involvement recurs. For the upper urinary tract conservative therapies may be advisable when noninfiltrating tumors are diagnosed even after cystectomy due to the high rate of bilateral new onset disease. When cystectomy is performed, extended excision of the upper urinary tract and pyelo-intestinal anastomosis may be considered.     

Effects of fasudil,a Rho‐kinase inhibitor,on contraction of pig bladder tissues with or without urothelium

Objectives: To investigate the effects of fasudil, a Rho‐associated serine‐threonine protein kinase inhibitor, on contraction of the pig urinary bladder tissues with or without urothelium. Methods: Cumulative concentration‐response curves (CRCs) to carbachol were obtained with and without 3–10 µM fasudil. Drug effects were evaluated in detrusor with and without urothelium. Inhibitory responses to fasudil were also examined in tissues precontracted with KCl and carbachol, and in response to electrical field stimulation, in pig bladder with and without urothelium. Results: In detrusor without urothelium, maximum contraction (E_max) decreased after administration of fasudil at 3 or 10 µmol/L (both P < 0.01), or 30 µmol/L (72.5 ± 7.43%, 58.4 ± 8.04% and 68.4 ± 9.6%, respectively, of the first curve). In detrusor with urothelium, E_max decreased significantly (all P < 0.05) after the addition of 3, 10 or 30 µmol/L of fasudil (84.9 ± 6.7%, 67.9 ± 5.2% and 35.2 ± 4.1%, respectively). In tissues precontracted with 80 mmol/L KCl or 100 µmol/L carbachol, tension after administration of fasudil (1 nmol/L to 100 µmol/L) decreased (by approximately 40%), only after administration of fasudil at high concentration (>1 µmol/L), in detrusor both with and without urothelium. In tissues with and without urothelium, responses to electrical field stimulation at 1–50 Hz decreased significantly in a concentration‐dependent manner after addition of fasudil (3 to 30 µmol/L). Conclusions: Fasudil seems to provoke relaxation of the bladder detrusor via both urothelium‐dependent and independent pathways.