Effect of α1D-adrenoceptor blocker for the reduction of ureteral contractions.

PURPOSE: Urolithiasis is a common urinary tract disease with growing prevalence. Alpha1-adrenoceptors (α1-ARs) are abundant in ureteral smooth muscle, distributed with different α1-AR subtypes. α1D-AR is the most widely distributed in the ureter. However, the effect of α1D-AR blockade on ureteric contraction remains unknown. MATERIALS AND METHODS: We dissected smooth muscle tissues (3 mm×3 mm) from the rat bladder and human ureter, tied silk strips on both tissue ends, and measured contraction in an organ bath chamber. Contraction activity in ureteral smooth muscle cells (USMCs) was immunocytochemically examined using primary rat and human USMC cultures. RESULTS: Using the organ bath system, we determined the inhibitory effects of silodosin, tamsulosin, and naftopidil. Naftopidil significantly decreased contractility of rat bladder tissue; similar results were observed in human ureteral tissue. To confirm ex vivo experimental results in vitro , we examined the phosphorylation of myosin light chain (MLC), a marker of contractility, in a primary human USMC culture. The examined drugs decreased phospho-MLC levels in human USMCs; however, naftopidil profoundly increased MLC dephosphorylation. CONCLUSIONS: We studied the effects of naftopidil, an α1D-AR inhibitor, on the ureter. Compared with alpha-blockers, naftopidil significantly relaxed ureteral smooth muscle. Therefore, naftopidil could be an effective therapy for patients with ureteral stones.

Current and emerging pharmacological targets for medical expulsive therapy.

The primary goals of medical expulsive therapy are to increase the rate of stone expulsion along the ureter to avoid ureteral obstruction and reduce ureteral colic and thus avoid the need for surgical and more invasive interventions. This review focussed on the findings from in vivo and in vitro animal and human studies that have investigated the pharmacological mechanisms controlling ureteral motility and their translation to current and potentially new clinically used drugs for increasing the rate of stone expulsion along the ureter. The complicated contractility profile of the ureter, which alters with age, tissue segment region, orientation and species contributes to the difficulty of interpreting studies on ureteral pharmacology, which translates to the complexity of discovering ideal drug targets for medical expulsive therapy. Nevertheless, the current drug classes clinically used for patients with stone lodgement include α1 -adrenoceptor antagonists, calcium channel blockers and NSAIDS, whilst there are promising targets for drug development that require further clinical investigations including the phosphodiesterase type 5 enzyme, ß-adrenoceptors and 5-HT receptors.

Time-dependent genomic response in primary human uroepithelial cells exposed to arsenite for up to 60 days.

Evidence from both in vivo and in vitro studies suggests that gene expression changes from long-term exposure to arsenite evolve markedly over time, including reversals in the direction of expression change in key regulatory genes. In this study, human uroepithelial cells from the ureter segments of 4 kidney-donors were continuously treated in culture with arsenite at concentrations of 0.1 or 1 µM for 60 days. Gene expression at 10, 20, 30, 40, and 60 days was determined using Affymetrix human genome microarrays and signal pathway analysis was performed using GeneGo Metacore. Arsenic treated cells continued to proliferate for the full 60-day period, whereas untreated cells ceased proliferating after approximately 30 days. A peak in the number of gene changes in the treated cells compared to untreated controls was observed between 30 and 40 days of exposure, with substantially fewer changes at 10 and 60 days, suggesting remodeling of the cells over time. Consistent with this possibility, the direction of expression change for a number of key genes was reversed between 20 and 30 days, including CFOS and MDM2. While the progression of gene changes was different for each subject, a common pattern was observed in arsenic treated cells over time, with early upregulation of oxidative stress responses (HMOX1, NQ01, TXN, TXNRD1) and down-regulation of immune/inflammatory responses (IKKα). At around 30 days, there was a transition to increased inflammatory and proliferative signaling (AKT, CFOS), evidence of epithelial-to-mesenchymal transition (EMT), and alterations in DNA damage responses (MDM2, ATM). A common element in the changing response of cells to arsenite over time appears to involve up-regulation of MDM2 by inflammatory signaling (through AP-1 and NF-κB), leading to inhibition of P53 function.

Including Medical Management in the Urologic Approach to Idiopathic Retroperitoneal Fibrosis.

OBJECTIVE: To characterize the timing and effectiveness of medical management in resolving stent-dependent ureteral compression secondary to idiopathic retroperitoneal fibrosis (RPF), the long-term relevant outcomes, and the side effects of treatment. METHODS: A retrospective review of RPF patients diagnosed from 2002-2018 was performed. Patients with hydronephrosis due to ureteral involvement that were managed with medication and with temporary stenting as needed, but without initial ureterolysis, were included. Patient demographics and RPF management details were obtained, including the following subsequent events: ureterolysis, nephrectomy, recurrent upper tract obstruction, and medication side effects. RESULTS: Fifty-two patients met inclusion criteria. Resolution of ureteral obstruction with medical management and temporary renal drainage as needed occurred in 36 (69%) patients with a median stent duration of 16 months, and median clinical and radiographic follow up of 4.2 and 3.3 years, respectively. Recurrent obstruction after a stent-free period occurred in 9 (18%) patients. Ureterolysis was performed in 8 (15%) patients at a median of 2.2 years for medication intolerance, lack of radiographic response to medication, or persisting pain. Potential medication side effects occurred in 6 (12%) patients. CONCLUSIONS: Medical management supported successful resolution of ureteral obstruction in 69% of patients without the need for ureterolysis after temporary renal drainage using stents, with rare incidence of worsening renal dysfunction or medication side effect. To date, this is the largest reported series of systematically managed RPF patients with obstructive uropathy receiving initial medical therapy and serves to counsel patients and advise urologists and nephrologists of the expected course and advantages and disadvantages of medical versus surgical management.

17ß-estradiol and ureteral contractility: A role for the G protein-coupled estrogen receptor.

The aim of this study was to investigate the unknown effects of 17ß-estradiol (E2) on ureteral contractility and the receptor and mechanisms involved. By utilising isolated porcine distal ureteral strips, we observed that E2 (30-300 µM) and a G protein-coupled estrogen receptor specific agonist G-1 (30 µM) both increased the frequency of phasic contractions of the ureter (P<0.05). E2 also decreased the maximum amplitude of these contractions (P<0.05). The G protein-coupled estrogen receptor specific antagonist G-36 (10 µM) reversed E2 enhancement effects on frequency, but did not alter its effects on maximum amplitude of contractile responses. Additionally, it was observed that the effects of E2 were unaltered by removing the urothelium, inhibiting nitric oxide and prostaglandin production or preventing neuronal conduction. In the presence of a potassium channel blocker, 4-aminopyridine (10 µM), the effects of E2 on frequency were prevented. This finding suggests that G protein-coupled estrogen receptor mediates the increase in frequency of ureteral phasic contractions induced by E2 via activation of potassium channels, while E2 alters the amplitude of these contractions through an unknown mechanism.

TRPM3 channel activation inhibits contraction of the isolated human ureter via CGRP released from sensory nerves.

AIMS: Sensory nerve activation modulates ureteral contractility by releasing neuropeptides including CGRP and neurokinin A (NKA). TRPM3 is a recently discovered thermosensitive channel expressed in nociceptive sensory neurons, and plays a key role in heat nociception and chronic pain. The aim of this study is to examine the role of TRPM3 activation in human ureter motility. MAIN METHOD: Human proximal ureters were obtained from fourteen patients undergoing nephrectomy. Spontaneous or NKA-evoked contractions of longitudinal ureter strips were recorded in an organ bath. Ureteral TRPM3 expression was examined by immunofluorescence. KEY FINDINGS: Spontaneous contractions were observed in 60% of examined strips. TRPM3 activation using pregnenolone sulphate (PS) or CIM0216 (specific TRPM3 agonists) dose-dependently reduced the frequency of spontaneous and NKA-evoked contractions, with IC50s of 241.7 µM and 4.4 µM, respectively. The inhibitory actions of TRPM3 agonists were mimicked by CGRP (10 to 100 nM) or a cAMP analogue (8-Br-cAMP; 1 mM). The inhibitory actions of TRPM3 agonists (300 µM PS or 30 µM CIM0216) were blocked by pretreatment with primidone (TRPM3 antagonist; 30 µM), tetrodotoxin (sodium channel blocker; 1 µM), olcegepant (CGRP receptor antagonist; 10 µM), or H89 (non-specific PKA inhibitor; 30 µM). TRPM3 was co-expressed with CGRP in nerves in the sub-urothelial and intermuscular regions of the ureter. SIGNIFICANCE: TRPM3 channels expressed on sensory terminals of the human ureter involve in inhibitory sensory neurotransmission and modulate ureter motility via the CGRP-cAMP-PKA signal pathway. Targeting TRPM3 may be a pharmacological strategy for promoting the ureter stone passage.

The transient receptor potential A1 ion channel (TRPA1) modifies in vivo autonomous ureter peristalsis in rats.

AIMS: The current study aimed to explore the expression of transient receptor potential A1 ion channels (TRPA1) in the rat ureter and to assess if TRPA1-active compounds modulate ureter function. METHODS: The expression of TRPA1 in rat ureter tissue was studied by immunofluorescence. The TRPA1 distribution was compared to calcitonin gene-related peptide (CGRP), α-actin (SMA1), anoctamin-1 (ANO1), and c-kit. For in vivo analyses, a catheter was implanted in the right ureter of 50 rats. Ureter peristalsis and pressures were continuously recorded by a data acquisition set-up during intraluminal infusion of saline (baseline), saline plus protamine sulfate (PS; to disrupt the urothelium), saline plus PS with hydrogen sulfide (NaHS) or cinnamaldehyde (CA). Comparisons were made between rats treated systemically with vehicle or a TRPA1-antagonist (HC030031). RESULTS: TRPA1-immunoreactive nerves co-expressed CGRP and were mainly located in the suburothelial region of the ureter. Immunoreactivity for TRPA1 was also encountered in c-kit-positive but ANO1-negative cells of the ureter suburothelium and wall. In vivo, HC030031-treated rats had elevated baseline peristaltic frequency (p < 0.05) and higher intraluminal pressures (p < 0.01). PS increased the frequency of ureter peristalsis versus baseline in vehicle-treated rats (p < 0.001) but not in HC030031-treated rats. CA (p < 0.001) and NaHS (p < 0.001) decreased ureter peristalsis. This was counteracted by HC030031 (p < 0.05 and p < 0.01). CONCLUSIONS: In rats, TRPA1 is expressed on cellular structures considered of importance for peristaltic and mechanoafferent functions of the ureter. Functional data indicate that TRPA1-mediated signals regulate ureter peristalsis. This effect was pronounced after mucosal disruption and suggests a role for TRPA1 in ureter pathologies involving urothelial damage.

Pooled analysis of the efficacy and safety of adjunctive alpha-blocker therapy before ureteroscopy in the management of ureteral stones.

OBJECTIVE: To evaluate the efficacy and safety of adjunctive alpha-blocker therapy before ureteroscopy in the management of ureteral stones. METHODS: The databases MEDLINE®, EMBASE and The Cochrane Controlled Trail Register of Controlled Trials were searched between January 1980 and June 2019 to identify randomized controlled trials (RCTs) that referred to the use of alpha-blockers as adjunctive therapy before ureteroscopy for the treatment of ureteral stones. Odds ratios (ORs) with 95% confidence intervals (CIs) were used for dichotomous outcomes; and mean difference (MD) with 95% CIs were used to report continuous outcomes. RESULTS: The analysis included five RCTs with a total of 557 patients. Compared with placebo, patients that received adjunctive alpha-blockers had significantly higher successful access to the stone (OR 5.44; 95% CI 2.99, 9.88), a significantly higher stone-free rate at the end of week 4 (OR 3.75; 95% CI 2.20, 6.39), significantly less requirement for balloon dilatation (OR 0.26; 95% CI 0.15, 0.44) and a significantly lower risk of complications (OR 0.25; 95% CI 0.15, 0.42). There was no significant difference in the operation time between the two groups (MD -3.33; 95% CI -7.03, 0.37). CONCLUSIONS: Adjunctive alpha-blocker therapy administered before ureteroscopy was effective in the management of ureteral stones with a lower risk of complications than placebo treatment.

Erythropoietin promotes functional recovery via anti-apoptotic mechanisms in mouse unilateral ureteral obstruction.

The purpose of the work was to investigate mechanisms of erythropoietin-induced protection and accelerated recovery of kidneys and ureters from obstructive injury. Unilateral ureteral obstruction was established for 24, 48, and 72 h in C57BL/6 mice using a non-traumatic micro-clip followed by the microscopic quantification of ureteral peristalsis pre- and post-obstruction. Expression of erythropoietin, erythropoietin receptor, ß-common receptor, and downstream apoptosis-related markers was assessed by RT-PCR and immunohistochemistry in ureters and kidneys and compared to the respective organs on the contralateral side within each animal. Expression of genes in kidneys and ureters from mice treated with 20 IU of erythropoietin daily for 72 h prior to obstruction was compared to that of untreated mice following obstruction. Apoptosis in ureteral tissues after 72-h obstruction was assessed via TUNEL assay. Ureteral obstruction increased apoptosis in affected ureters, with peristaltic function halted following all periods of obstruction. Erythropoietin treatment suppressed apoptosis in obstructed tissues and increased the percentage of mice retaining ureteral function immediately following obstruction reversal. Erythropoietin, erythropoietin receptor, Bcl-2, and Bcl-xl mRNA expression were down-regulated, while phospho-Nf-ĸb p65 was up-regulated in ureteral epithelia following obstruction. Erythropoietin treatment induced anti-apoptotic signaling via down-regulated Bax mRNA expression and abrogated phospho-Nf-ĸb p65. Erythropoietin-induced protection of ureteral function and accelerated recovery post-obstruction removal is mediated via anti-apoptotic mechanisms. Ureteral function is disrupted even following obstruction removal, negatively affecting renal function due to delayed recovery. Thus, our results represent a potential target for the development of safe therapeutic agents aimed at improving functional recovery from obstructive injury.

Paclitaxel-coated stents to prevent hyperplastic proliferation of ureteral tissue: from in vitro to in vivo.

Ureteric stents have become an indispensable tool in the armamentarium of every urologist. However, they carry their own morbidity resulting mostly from infectious or abacterial fouling and biofilm formation, and/or urothelial hyperplastic reaction. All of these may interact and lead to clinical complications. Many different stent designs and coatings have been proposed. In this study, we focused on the effect of paclitaxel-coated stents on hyperplastic proliferation of ureteral tissue, using as example anastomotic strictures after ureteroureterostomy in a rat model. Human urothelial cells (SV-HUC-1) were used to determine paclitaxel dosages in vitro. Polyurethane stents were coated with a paclitaxel containing biodegradable polymer and studied in a ureteroureterostomy rat model. 48 male 9-week-old Sprague-Dawley rats underwent either sham surgery (n = 16) or ureteroureterostomy with sutured anastomosis, and consecutive stenting with either a paclitaxel-coated or an uncoated stent (16 per group), respectively. The animals received daily intraperitoneal injections of 5-bromo-2-deoxyuridine (20 mg/ml, 100 mg/kg body weight) during the first eight postoperative days, and were sacrificed on day 28. Healing of the ureteral anastomosis and proliferation of urothelial cells was examined histologically and immunohistochemically. In vitro, a concentration of 10 ng/mm2 paclitaxel can be considered as non-toxic, while still exerting an anti-proliferative effect on urothelial cells. Histologically, typical wound healing processes were seen at the site of the ureteral anastomosis in vivo. Proliferation of urothelial cells was significantly lower in animals with paclitaxel-coated stents compared to those with uncoated stents (LI 41.27 vs. 51.58, p < 0.001). Our results indicate that stenting of ureteral anastomoses with paclitaxel-coated stents can reduce hyperplastic proliferation of ureteral tissue. Paclitaxel-coated stents thus might be able to prevent not only scar-induced postoperative stenosis after reconstructive surgery, but also hyperplastic urothelial reaction in non-anastomotic stent patients as part of their inflammatory response to the foreign material.

Identification and local delivery of vasodilators for the reduction of ureteral contractions.

Kidney stones and ureteral stents can cause ureteral colic and pain. By decreasing contractions in the ureter, clinically prescribed oral vasodilators may improve spontaneous stone passage rates and reduce the pain caused by ureteral stenting. We hypothesized that ureteral relaxation can be improved via the local administration of vasodilators and other smooth muscle relaxants. Here, by examining 18 candidate small molecules in an automated screening assay to determine the extent of ureteral relaxation, we show that the calcium channel blocker nifedipine and the Rho-kinase inhibitor ROCKi significantly relax human ureteral smooth muscle cells. We also show, by using ex vivo porcine ureter segments and sedated pigs that, with respect to the administration of a placebo, the local delivery of a clinically deployable formulation of the two drugs reduced ureteral contraction amplitude and frequency by 90% and 50%, respectively. Finally, we show that standard oral vasodilator therapy reduced contraction amplitude by only 50% and had a minimal effect on contraction frequency. Locally delivered ureteral relaxants therefore may improve ureter-related conditions.

A porcine model of ureteral contractile activity: Influences of age, tissue orientation, region, urothelium, COX and NO.

INTRODUCTION: We aimed to investigate factors contributing to ureteral responses and establish a reliable porcine model for studying ureteral contractility. METHODS: Isolated ureteral strips from young (6-month old) and older (3-year old) pigs were mounted in organ baths and subjected to phenylephrine, 5-HT, carbachol and histamine. Ureteral strips developed bursts of contractile activity which was measured as area under the curve (AUC) and frequency. Phenylephrine and 5-HT-induced responses of proximal and distal ureters were obtained, in the presence and absence of indomethacin (10 µM) and L-NNA (100 µM), and the influence of an intact mucosa was examined. RESULTS: Phenylephrine and 5-HT-induced contractile responses were greater than those to carbachol in the porcine ureter. In fact, responses to carbachol were only present in ureters from older animals. Ureters suspended longitudinally had increased phenylephrine-induced contractions compared to those suspended circularly (p < .05). A greater amount of tissue strips developed spontaneous contractions from the proximal region compared to distal (83% vs 25%). There was an increase in maximum phenylephrine-induced responses in the distal ureter when compared to the proximal ureter (p < .05). In the presence of indomethacin, only 5-HT-induced contractions in the young animals were depressed (p < .05) while L-NNA did not affect any ureteral responses. The intact mucosa significantly decreased contractile responses to phenylephrine and 5-HT in the porcine ureter. DISCUSSION: The complexity of ureteral contractions depicting bursts of phasic activity requires AUC assessment. Porcine ureteral contractile properties, such as regional differences, influence of mucosa and lack of response to carbachol, are similar to those reported in the literature for human ureter.

Overactivity or blockade of transforming growth factor-ß each generate a specific ureter malformation.

Transforming growth factor-ß (TGFß) has been reported to be dysregulated in malformed ureters. There exists, however, little information on whether altered TGFß levels actually perturb ureter development. We therefore hypothesised that TGFß has functional effects on ureter morphogenesis. Tgfb1, Tgfb2 and Tgfb3 transcripts coding for TGFß ligands, as well as Tgfbr1 and Tgfbr2 coding for TGFß receptors, were detected by quantitative polymerase chain reaction in embryonic mouse ureters collected over a wide range of stages. As assessed by in situ hybridisation and immunohistochemistry, the two receptors were detected in embryonic urothelia. Next, TGFß1 was added to serum-free cultures of embryonic day 15 mouse ureters. These organs contain immature smooth muscle and urothelial layers and their in vivo potential to grow and acquire peristaltic function can be replicated in serum-free organ culture. Such organs therefore constitute a suitable developmental stage with which to define roles of factors that affect ureter growth and functional differentiation. Exogenous TGFß1 inhibited growth of the ureter tube and generated cocoon-like dysmorphogenesis. RNA sequencing suggested that altered levels of transcripts encoding certain fibroblast growth factors (FGFs) followed exposure to TGFß. In serum-free organ culture exogenous FGF10 but not FGF18 abrogated certain dysmorphic effects mediated by exogenous TGFß1. To assess whether an endogenous TGFß axis functions in developing ureters, embryonic day 15 explants were exposed to TGFß receptor chemical blockade; growth of the ureter was enhanced, and aberrant bud-like structures arose from the urothelial tube. The muscle layer was attenuated around these buds, and peristalsis was compromised. To determine whether TGFß effects were limited to one stage, explants of mouse embryonic day 13 ureters, more primitive organs, were exposed to exogenous TGFß1, again generating cocoon-like structures, and to TGFß receptor blockade, again generating ectopic buds. As for the mouse studies, immunostaining of normal embryonic human ureters detected TGFßRI and TGFßRII in urothelia. Collectively, these observations reveal unsuspected regulatory roles for endogenous TGFß in embryonic ureters, fine-tuning morphogenesis and functional differentiation. Our results also support the hypothesis that the TGFß up-regulation reported in ureter malformations impacts on pathobiology. Further experiments are needed to unravel the intracellular signalling mechanisms involved in these dysmorphic responses. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Positive outcomes of phosphodiesterase type 5 inhibitor on histopathologic and biochemical changes induced by ureteral obstruction.

OBJECTIVES: We examined the effects of tadalafil, one of the phosphodiesterase type 5 (PDE5) inhibitors, in a rat model of with partial and complete unilateral ureteral obstruction (UUO). METHODS: The rats were divided into 5 groups: sham (n=6), partial unilateral ureteral obstruction (PUUO, n=6), PUUO with tadalafil treatment (PUUO+T; Cialis, 10 mg/72 h, intragastric; Lilly, Indianapolis, Indiana, USA), complete unilateral ureteral obstruction (CUUO, n=6), and CUUO with tadalafil treatment (CUUO+T). RESULTS: Fifteen days after the UUO, the ureter presented changes in the layers of urothelium and significant infiltration of inflammatory cells in the PUUO and CUUO groups. Compared with the sham, PUUO and CUUO groups had severe increased inflammatory cell infiltration. The urothelial epithelium exhibited cell degeneration and loss because of the swollen, atrophic, and denuded epithelial cells in the PUUO and CUUO groups. In the PUUO+T and CUUO+T groups, the urothelium revealed less epithelial cell degeneration and loss.The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-ß (TGF-ß) exhibited up-regulation in the PUUO and CUUO groups. The expression of TGF-ß decreased positively correlated with that of α-SMA in the tadalafil therapy groups, PUUO+T and CUUO+T. CONCLUSION: The phosphodiesterase type 5 inhibitor's tadalafil reduced expressions of α-SMA and TGF-ß in the obstructed ureters, measured by biochemical examinations. In addition, tadalafil decreased urothelium degeneration due to the decreased epithelial cell loss and inflammatory cell infiltration. Our results show that tadalafil prevents or slows down the onset of ureter inflammation and urothelial degeneration in rats with UUO.

Effect of forced diuresis during 18F-DCFPyL PET/CT in patients with prostate cancer: activity in ureters, kidneys and bladder and occurrence of halo artefacts around kidneys and bladder.

Forced diuresis may improve readability of 2-(3-(1-carboxy-5-[(6-[F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentanedioic acid (F-DCFPyL) PET/computed tomography (CT) by reducing focal ureteral activity. A total of 40 patients received furosemide simultaneously with F-DCFPyL (cohort 1) and 40 patients received furosemide 85 min after F-DCFPyL administration (cohort 2). The frequency of occurrence of activity depositions in ureters and halo artefacts near the kidneys and bladder was measured, as well as intensity of F-DCFPyL uptake in kidneys and bladder. At 120 min after injection of F-DCFPyL, a significantly lower number of F-DCFPyL depositions in ureters was found in cohort 2. Moreover, F-DCFPyL uptake in kidneys and bladder was significantly lower in this cohort; however, the occurrence of halo artefacts was similar in both groups. Administration of furosemide may improve interpretation of F-DCFPyL PET/CT as it results in less activity depositions in ureters. However, the effect depends on the timing of furosemide administration in relation to F-DCFPyL administration and PET/CT acquisition time. Acquisition of PET-images 120 min after F-DCFPyL administration benefits from late furosemide administration (85 min after injection).

Positive outcomes of phosphodiesterase type 5 inhibitor on histopathologic and biochemical changes induced by ureteral obstruction

SUMMARY OBJECTIVES: We examined the effects of tadalafil, one of the phosphodiesterase type 5 (PDE5) inhibitors, in a rat model of with partial and complete unilateral ureteral obstruction (UUO). METHODS: The rats were divided into 5 groups: sham (n=6), partial unilateral ureteral obstruction (PUUO, n=6), PUUO with tadalafil treatment (PUUO+T; Cialis, 10 mg/72 h, intragastric; Lilly, Indianapolis, Indiana, USA), complete unilateral ureteral obstruction (CUUO, n=6), and CUUO with tadalafil treatment (CUUO+T). RESULTS: Fifteen days after the UUO, the ureter presented changes in the layers of urothelium and significant infiltration of inflammatory cells in the PUUO and CUUO groups. Compared with the sham, PUUO and CUUO groups had severe increased inflammatory cell infiltration. The urothelial epithelium exhibited cell degeneration and loss because of the swollen, atrophic, and denuded epithelial cells in the PUUO and CUUO groups. In the PUUO+T and CUUO+T groups, the urothelium revealed less epithelial cell degeneration and loss. The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β) exhibited up-regulation in the PUUO and CUUO groups. The expression of TGF-β decreased positively correlated with that of α-SMA in the tadalafil therapy groups, PUUO+T and CUUO+T. CONCLUSION: The phosphodiesterase type 5 inhibitor's tadalafil reduced expressions of α-SMA and TGF-β in the obstructed ureters, measured by biochemical examinations. In addition, tadalafil decreased urothelium degeneration due to the decreased epithelial cell loss and inflammatory cell infiltration. Our results show that tadalafil prevents or slows down the onset of ureter inflammation and urothelial degeneration in rats with UUO.

RESUMO OBJETIVOS: Examinamos os efeitos do tadalafil em um dos inibidores da fosfodiesterase tipo 5 (PDE5) em um modelo de rato com obstrução ureteral unilateral parcial e completa (UUO). MÉTODOS: Os ratos foram divididos em cinco grupos: sham (n = 6), obstrução ureteral unilateral parcial (PUUO, n = 6), PUUO com tadalafil (PUUO T; Cialis, 10 mg/72 h, intragástrica; Lilly, Indianapolis, Indiana, EUA), completa obstrução ureteral unilateral (CUUO, n = 6) e CUUO com tratamento com tadalafil (CUUO T). RESULTADOS: Quinze dias após a UUO, o ureter apresentou alterações nas camadas de urotélio e infiltração significativa de células inflamatórias nos grupos PUUO e CUUO. Em comparação com os grupos sham, PUUO e CUUO, houve um aumento grave da infiltração de células inflamatórias. O epitélio urotelial exibiu degeneração e perda celular devido às células epiteliais inchadas, atróficas e desnudas nos grupos PUUO e CUUO. Nos grupos PUUO T e CUUO T, o urotélio revelou menor degeneração e perda de células epiteliais. Nós mostramos que a expressão da actina do músculo liso-α (α-SMA) e do fator de crescimento transformador-β (TGF-β) foram exibidas como sub-regulação nos grupos PUUO e CUUO. A expressão do TGF-β foi diminuída positivamente correlacionada com a da α-SMA nos grupos de terapia com tadalafil, PUUO T e CUUO T. CONCLUSÃO: O tadalafil do inibidor da fosfodiesterase tipo 5 reduziu as expressões α-SMA e TGF-β nos ureteres obstruídos, medidos por exames bioquímicos. Além disso, o tadalafil diminuiu a degeneração do urotélio devido à diminuição da perda de células epiteliais e da infiltração de células inflamatórias. Nossos resultados mostram que o tadalafil previne ou retarda o início da inflamação do ureter e degeneração urotelial em ratos com UUO.

Mirabegron: A Novel and Promising Medical Expulsive Treatment for Ureteral Stones?

Medical expulsive therapy (MET) is used especially in distal ureteral stones to reduce colics and decrease the number of endourological surgical interventions. A broad spectrum of agents can be used for the relaxation and the dilatation of the ureter, reducing the intraureteric pressure. Alfa-blockers, calcium channel blockers, phosphodiesterase (PDE) inhibitors, and spasmolytics have been shown as effective in clinical trials on urolithiasis. It is a fact that the urothelium itself, the interstitial cells and the ureteric smooth muscle, have B-beta-2 and beta-3 adrenoreceptors. Stimulation of these receptors results in relaxation of the ureter. A recent beta-3 agonist, mirabegron, is commonly used for overactive bladder nowadays. The mechanism of action is adrenergic agonism that affects with the storage phase of the bladder, without interfering the voiding phase, which is regulated by parasympathetic pathways, commonly muscarinic. Agonism of the beta-3 receptors in the ureter has been shown to decrease the intraluminal pressure. By this mechanism, mirabegron can be thought as an alternative MET agent. Acting through different pathways, and having low adverse effect profile, can be thought as the most striking advantages of mirabegron as a MET. In vitro and in vivo trials should be conducted to support this hypothesis.

The modulation of ureteral smooth muscle contractile responses by α1- and α2-adrenoceptor activation.

PURPOSE: This study was performed to investigate the influence of α-adrenoceptor subtypes upon ureteral smooth muscle contractile responses. METHODS: Rat ureters were challenged in vitro with noradrenaline (NA), the α1-adrenoceptor agonist phenylephrine (PE), and the α2-adrenoceptor agonist clonidine (CLON). The influences of the agonists on the magnitude and frequency of acetylcholine (ACh)-stimulated phasic contractile responses were recorded. RESULTS: The magnitude of the phasic contractile responses effected by ACh was not significantly influenced by the adrenoceptor agonists, but the frequency of the response was significantly enhanced by all three agonists (p < 0.05). Idazoxan and prazosin abolished the rise in frequency effected by CLON and PE, respectively, whereas both antagonists in combination were required to abolish the increase in frequency effected by NA. CONCLUSIONS: It has been demonstrated that α1- and α2-adrenoceptors modulate the contractile function of rat ureteral smooth muscle by increasing the frequency, but not the magnitude, of phasic contractile responses. The enhancement of contractile function by NA is mediated by mechanisms dependent upon both α1- and α2-adrenoceptors.

Cu-bearing stainless steel reduces cytotoxicity and crystals adhesion after ureteral epithelial cells exposing to calcium oxalate monohydrate.

Calcium oxalate monohydrate (COM), which is the main component of encrustation, may result in cell membrane injury. In addition, cellular damage is suggested to be the primary event attributing to COM crystal binding. To study the interaction between cells and crystals after incubating with a Cu-bearing stainless steel (316L-Cu SS), MTS and flow cytometric analyses were used to assess the cellular responses. The results confirmed that 316L-Cu SS could inhibit cytotoxicity and cellular apoptosis of ureteral epithelial cells (UECs) after COM treatment. Furthermore, molecular expressions of Cu/Zn superoxide dismutase (CuZnSOD), which were evaluated by western blot analysis and real-time quantitative PCR (qPCR), indicated that 316L-Cu SS could inhibit the oxidative stress attributing to up-regulating of CuZnSOD. Moreover, the crystal adhesion cytokine CD44 was examined with western blot and qPCR, and the corresponding hyaluronic (HA) secreted into the medium was measured by enzyme-linked immunosorbent assay (ELISA). All results were confirmed that the expressions of cells cultured with 316L-Cu SS were down-regulated, demonstrating the inhibitory performance of 316L-Cu SS against crystal adhesion.