Effect of partial urethral obstruction on force development of the guinea pig bladder

We created gradual partial urethral obstruction in 20 guinea pigs using silver jeweler's jump rings. After 4 or 8 weeks obstruction all animals underwent cystometry and were assigned to one of five urodynamic categories: normal, high pressure voiding, unstable, low compliance, or decompensated. After sacrifice, the contractile responses of bladder strips to electrical field stimulation of intramural nerves, direct electrical muscle stimulation, 0.1 mM carbachol, and high K + solution were sampled by computer for phase plot analysis. Following 8 weeks obstruction, the value of the phase plot parameter Fiso, indicative of the number of contractile muscle units, was reduced to 60% of the control response to nerve stimulation (P < 0.05) and to 77% of the control response to carbachol stimulation (P < 0.05). Parameter C, the slope of the phase plot (indicative of unit recruitment during force development), was unchanged for all forms of stimulation. Although in the latter case not statistically significant, obstruction affected responses to nerve and muscle stimulation similarly suggesting that muscle change may possibly be a common denominator of dysfunction. In view of the reduction in Fiso and the increase in bladder weight, instability may represent a more advanced form of dysfunction due to obstruction than high pressure voiding

Distribution and chemical coding of neurons in intramural ganglia of the porcine urinary bladder trigone.

This study presents the distribution and chemical coding of neurons in the porcine intramural ganglia of the urinary bladder trigone (IG-UBT) demonstrated using combined retrograde tracing and double-labelling immunohistochemistry. Retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of both the left and right side of the bladder trigone during laparotomy performed under pentobarbital anaesthesia. Ten-microm-thick cryostat sections were processed for double-labelling immunofluorescence with antibodies against tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), calcitonin gene-related peptide (CGRP), substance P (SP), Leu5-enkephalin (LENK) and choline acetyltransferase (ChAT). IG-UBT neurons formed characteristic clusters (from a few to tens neuronal cells) found under visceral peritoneum or in the outer muscular layer. Immunohistochemistry revealed four main populations of IG-UBT neurons: SOM- (ca. 35%), SP- (ca. 32%), ChAT- and NPY- immunoreactive (-IR) (ca. 23%) as well as non-adrenergic non-cholinergic nerve cells (ca. 6%). This study has demonstrated a relatively large population of differently coded IG-UBT neurons, which constitute an important element of the complex neuro-endocrine system involved in the regulation of the porcine urogenital organ function

Effects of nitric oxide inhibitors in mice with bladder outlet obstruction

To investigate the lower urinary tract changes in mice treated with L-NAME, a non-selective competitive inhibitor of nitric oxide synthase (NOS), or aminoguanidine, a competitive inhibitor of inducible nitric oxide synthase (iNOS), after 5 weeks of partial bladder outlet obstruction (BOO), in order to evaluate the role of constitutive and non-constitutive NOS in the pathogenesis of this experimental condition. Materials and Methods: C57BL6 male mice were partially obstructed and randomly allocated into 6 groups: Sham, Sham + L-NAME, Sham + aminoguanidine, BOO, BOO + L-NAME and BOO + aminoguanidine. After 5 weeks, bladder weight was obtained and cystometry and tissue bath contractile studies were performed. Results: BOO animals showed increase of non-voiding contractions (NVC) and bladder capacity, and also less contractile response to Carbachol and Electric Field Stimulation. Inhibition of NOS isoforms improved bladder capacity and compliance in BOO animals. L-NAME caused more NVC, prevented bladder weight gain and leaded to augmented contractile responses at muscarinic and electric stimulation. Aminoguanidine diminished NVC, but did not avoid bladder weight gain in BOO animals and did not improve contractile responses. Conclusion: It can be hypothesized that chronic inhibition of three NOS isoforms in BOO animals leaded to worsening of bladder function, while selective inhibition of iNOS did not improve responses, what suggests that, in BOO animals, alterations are related to constitutive NOS432356366CAPES – COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORsem informaçã

Histología uretral y vaginal en algunas hembras de mamíferos

El análisis de las características histológicas de la uretra y la vagina en hembras de mamíferos es útil para entender la fisiología y la patología de procesos como la continencia urinaria, la cópula y el parto. En este contexto, las especies más estudiadas en cuanto a la organización tisular de la uretra y vagina son la rata y la coneja. Es necesario estudiar con más detalle la organización tisular de la vagina y uretra en diferentes especies con fines de comparación. Tal información permitiría entender la diversidad funcional y conductual asociada a estos órganos. El presente documento reúne, compara y discute la información existente sobre las características histológicas de la uretra y la vagina en algunas hembras de mamíferos destacando aquellas de la coneja, modelo utilizado por nuestro grupo de investigación para estudiar la fisiología reproductiva y urinaria femenina

Effects of L-Arginine on Bladder Function in Bladder Outlet-Obstructed Rats

Nitric oxide (NO) is thought to play an important role in the lower urinary tract. We therefore studied the effects of NO on bladder function in bladder outlet-obstructed rats. Twelve-week-old female Wistar rats had their bladder outlets partially obstructed by ligating the urethra over which a catheter was placed. Micturition parameters and urodynamic parameters were measured in 6 groups of rats: Group I, 1 week after sham operation; Group II, 1 week after surgical induction of bladder outlet obstruction; Group III, 150-mg/kg/day L-arginine injected intraperitoneally for 1 week after surgical induction of bladder outlet obstruction; Group IV, 6 weeks after sham operation; Group V, 6 weeks after surgical induction of bladder outlet obstruction and Group VI, 150-mg/kg/day L-arginine injected intraperitoneally for 6 weeks after surgical induction of bladder outlet obstruction. Moreover, the area density of smooth muscle versus connective tissue was determined in bladder specimens using color assisted computer image analysis in these groups. The number of micturitions per day of the 1- and 6-week obstructed rats significantly increased over that of the sham-operated rats. The number of micturitions per day of the obstructed rats treated with L-arginine for 1 and 6 weeks significantly decreased in comparison to that of the obstructed rats. In the urodynamic study, the maximum detrusor pressure of the obstructed rats for 1 and 6 weeks significantly increased over that of the sham-operated rats. Residual urine volume of the obstructed rats for 1 and 6 weeks significantly increased over that of the sham-operated rats. The maximum detrusor pressure and residual urine volume of the obstructed rats treated with L-arginine for 1 and 6 weeks significantly decreased over those of the obstructed rats. In the histological study, the area density of smooth muscle versus connective tissue of the 1- and 6-week obstructed rats significantly increased over that of the sham-operated rats. Histological changes in the 1- and 6-week obstructed rats were prevented by treatment with L-arginine. These results indicate that L-arginine has a beneficial effect on bladder dysfunction in bladder outlet-obstructed rats. This might be due to L-arginine's influence in increasing NO levels and the rate of blood flow in the obstructed bladder

Organ-sparing reconstructive surgery in penile cancer: initial experiences at two Swedish referral centres.

Abstract Objective. The aim of this study was to present early outcome data for patients treated for penile cancer with organ-sparing reconstructive surgery at two referral centres in Sweden. Material and methods. Oncological, cosmetic and functional outcome and complications were analysed retrospectively during the period 2011-2013. Twelve patients with non-invasive penile cancer were treated with glans resurfacing (GR), while 15 patients with invasive penile cancer underwent total glansectomy with neoglans reconstruction (TGN). Results. The 12 patients treated with GR had a median age of 66 years (range 35-83 years) and a median follow-up time of 16 months (range 4-40 months). All patients showed carcinoma in situ and negative surgical margins in the final pathology report. The 15 patients treated with TGN had a median age of 71 years (range 37-78 years) and the median follow-up time was 10 months (range 1-25 months). All patients had invasive penile cancer and the surgical margins were negative in all cases except one. Complications occurred in five of the 27 patients (18%), and in most cases these were minor and infection related. No recurrences were seen in either group during follow-up, and all patients except one, who had undergone GR, were satisfied with the functional and cosmetic results. Conclusions. GR and TGN seem to be oncologically safe procedures for treating carefully selected patients with penile cancer, and the functional and cosmetic results are promising. Based on these findings, the authors recommend that penile amputation should only be carried out in patients who are not suitable for organ-sparing reconstructive surgery

The pharmacology of the autonomic control of the female rat urethra: Relevance to micturition.

The storage and periodic elimination of urine (micturition) is dependent upon a complex co-ordination of activities in the bladder and urethra. Nitric oxide (NO) has been suggested to play a role in the urethral control. The effects of NO are mediated by increases in guanosine 3':5'-cyclic monophosphate (cGMP) formation, which is broken down by a family of phosphodiesterases (PDEs), including PDE 5. However, the exact roles of this transduction system in the urethra are unknown. Therefore, the present experiments examined the effects of this pathway on changes in urethral and bladder pressures caused by bladder distension (micturition reflex) in urethane-anaesthetised female rats. As changes in urethral tone are due to both smooth and striated muscle (external urethral sphincter; EUS) EMG recordings were made to assess changes in EUS tone (EUS-EMG). The roles of NO/cGMP signalling in vitro were examined in the isolated female rat urethra. L-NAME, a NO synthase (NOS) inhibitor significantly attenuated reflex-evoked urethral relaxations and increased EUS-EMG activity and baseline urethral tone. Following neuromuscular blockade with α-Bungarotoxin (α-BT), L- NAME still attenuated urethral relaxations, but did not cause an increase in EUS-EMG or baseline tone. This supports the view that NO mediates urethral smooth muscle relaxations during voiding, and also indicates that there is a tonic release of NO inhibiting EUS-EMG activity. As would be expected, zaprinast, a PDE types 1, 5, 6 and 9 inhibitor, significantly potentiated reflex-evoked urethral relaxations. However, zaprinast also increased background and reflex-evoked EUS-EMG activity. Surprisingly, this ability to potentiate reflex-evoked relaxations was blocked by α-BT indicating that it is due to the ability of zaprinast to increase EUS-EMG activity. It is possible that this ability to increase EUS-EMG is indirect by causing changes in smooth muscle tone. This was investigated by examining the effects of urethral smooth muscle relaxation with intraurethral perfusion of isoprenaline and sodium nitroprusside on EUS-EMG activity. These relaxations were associated with an increase in EUS activity, and were inhibited by the ganglion blocker, chlorisondamine, supporting this view. Further experiments in the isolated female rat urethra demonstrated that L-NAME increased urethral tone and attenuated electrically-evoked (TTX sensitive) urethral relaxations. Nicotinic agonists evoked urethral relaxations, which were attenuated by L-NAME and inhibited by hexamethonium and chlorisondamine, but were TTX resistant. Zaprinast decreased urethral tone, although re-tensioning tissues to pre-drug levels unmasked a potentiation of the duration of electrically-evoked urethral relaxations at low frequencies of stimulation (1-4 Hz). These results indicate that reflex-, electrical- and nicotinic agonist-evoked urethral relaxations are mediated by NO. In vitro, these effects appear to be mediated by increases in cGMP. However, the ability of zaprinast to potentiate urethral relaxations in vivo are due to an ability to increase EUS activity, and conclusive evidence for the involvement of cGMP in the urethra in vivo could not be demonstrated. Further, the data indicates that there is an interaction between urethral smooth and striated muscles, mediated by ganglionic nicotinic receptors. In addition to the complex effects of the NO/cGMP pathway on this musculature, the above interactions complicate investigations regarding the effects of zaprinast in the urethra in vivo

In vitro functional properties of the rat bladder regenerated by the bladder acellular matrix graft.

PurposeTo assess the response of rat urinary bladder regenerated by the homologous bladder acellular matrix graft (BAMG) to in vitro electrical and pharmacologic stimuli.Materials and methodsIn Sprague-Dawley rats, partial cystectomy (&gt;50%) was performed, followed by BAMG augmentation cystoplasty. After 4 months, organ bath studies of tissue strips in 10 were used to compare the contractility of the BAMG regenerates and the corresponding host detrusor smooth muscle.ResultsThe BAMG regenerates exhibited contractile activity to electrical field stimulation and a qualitatively identical pattern of response to muscarinic, purinergic, alpha- and beta-adrenergic drug administration and nitric oxide. At 4 months after surgery, the maximum forces of contraction of the BAMG regenerates to carbachol stimulation amounted to close to 80% of the host bladder response. With electrical field stimulation, they equaled 44% and 62% of the host bladder response after 2.5 and 4 months, respectively. Histological and immunohistochemical studies confirmed the presence of receptors for neurotransmitters that these functional in vitro studies implied.ConclusionsThe present study provides further evidence that augmentation cystoplasty with the BAMG leads to functional regeneration of the rat bladder detrusor smooth muscle

Changes in Angiotensin II Type 1 Receptor Expression in the Rat Bladder by Bladder Outlet Obstruction

Purpose: To demonstrate the change in the expression of angiotensin II type 1 receptor (AT1) in the rat bladder with partial bladder outlet obstruction (P-BOO). Materials and Methods: Bladder specimens were obtained from 12-week-old Wistar female rats that were divided into two groups, a P-BOO group and a control group. The rats of the P-BOO group were divided into six groups: a sham-operated control group, 1 day postoperatively, 2 days postoperatively, 4 days postoperatively, 7 days postoperatively and 14 days postoperatively. The cystometric findings and immunohistochemical staining of the detrusor muscle with the AT1 antibody were compared in each group. Results: AT1 localized on the cell membrane of the detrusor smooth muscle and in cytoplasm of suburothelial myofibroblasts in the control rats. The expression of AT1 disappeared in the detrusor muscle and suburothelial myofibroblasts in P-BOO, but AT1 was highly expressed in urothelial cells 1 day after surgery. The expression of AT1 in urothelial cells gradually decreased with time after surgery. AT1 completely disappeared in urothelial cells 14 days after surgery. Conclusions: The present study demonstrated that the site of AT1 expression changes in response to the mechanical stress caused by P-BOO, and finally there was no expression of AT1 in rat bladder tissue following P-BOO. These data suggest the change in AT1 expression may play a role in bladder function