Obstruction In Rats Research Articles

Protective effect of Urtica dioica on liver damage induced by biliary obstruction in rats

The aim of this study was to evaluate the possible protective effects of Urtica dioica (UD) against liver damage in the common bile duct-ligated rats. A total of 24 male Sprague Dawley rats were divided into three groups, namely, control, bile duct ligation (BDL) and BDL+received UD groups, containing eight animals in each group. The rats in UD-treated groups were given UD oils (2ml/kg) once a day intraperitoneally for 2weeks starting 3days prior to BDL operation. The change demonstrating the bile duct proliferation and fibrosis in expanded portal tracts includes the extension of proliferated bile ducts into the lobules; inflammatory cell infiltration into the widened portal areas were observed in BDL group. Treatment of BDL with UD attenuated alterations in liver histology. The α-smooth muscle actin, cytokeratin-positive ductular proliferation and the activity of terminal deoxynucleotidyl transferase dUTP nick end labeling in the BDL were observed to be reduced with the UD treatment. The data indicate that UD attenuates BDL-induced cholestatic liver injury, bile duct proliferation and fibrosis.

Inhibition of Collagen Deposit in Obstructed Rat Bladder Outlet by Transplantation of Superparamagnetic Iron Oxide-Labeled Human Mesenchymal Stem Cells as Monitored by Molecular Magnetic Resonance Imaging (MRI)

Bladder outlet obstruction (BOO) caused by collagen deposit is one of the most common problems in elderly males. The present study is to investigate if human mesenchymal stem cells (MSCs) are capable of inhibiting collagen deposition and improve cystometric parameters in bladder outlet obstruction in rats. Human MSCs were labeled with nanoparticles containing superparamagnetic iron oxide (SPION), and transplanted in rat BOO lesion site. Forty 6-week-old female Sprague-Dawley rats were divided into four groups (group 1: control, group 2: sham operation, group 3: BOO, and group 4: BOO rats receiving SPION-hMSCs). Two weeks after the onset of BOO, 1 × 10(6) SPION-hMSCs were injected into the bladder wall. Serial T2-weighted MR images were taken immediately after transplantation of SPION-labeled human MSCs and at 4 weeks posttransplantation. T2-weighted MR images showed a clear hypointense signal induced by the SPION-labeled MSCs. While the expression of collagen and TGF-β protein increased after BOO, the expression of both returned to the original levels after MSC transplantation. Expression of HGF and c-met protein also increased in the group with MSC transplantation. Maximal voiding pressure and residual urine volume increased after BOO but they recovered after MSC transplantation. Human MSCs transplanted in rat BOO models inhibited the bladder fibrosis and mediated recovery of bladder dysfunction. Transplantation of MSC-based cell therapy could be a novel therapeutic strategy against bladder fibrosis in patients with bladder outlet obstruction.

Adenosine Receptors Are Up-Regulated in Unilateral Ureteral Obstructed Rat Kidneys

Despite recent improvements in immunosuppressive regimens, chronic renal allograft rejection remains a major problem. Tubulointerstitial fibrosis is one of the major histological features of chronic renal allograft rejection, but its exact pathogenic mechanisms are not fully understood. Adenosine present in the normal kidney is significantly elevated in response to cellular damage. The cellular effect of adenosine occurs through 4 known adenosine receptor (AR) subtypes; A1AR, A2AAR, A2BAR, and A3AR. All AR subtypes are expressed in the kidney, but the expression of each AR subtype has not been defined under fibrotic conditions. In the present study, we examined AR subtype expression in kidneys that underwent unilateral ureteral obstruction (UUO), a well-characterized model for tubulointerstitial fibrosis. At 5 days after the induction of UUO, we observed α-smooth muscle actin (α-SMA), fibronectin, and collagen I messenger RNA (mRNA) and protein expressions to be significantly up-regulated in the obstructed compared with the sham kidneys, confirming that fibrosis had occurred in the former organs. A1AR mRNA expression in the obstructed kidney cortex was 3.2-fold higher than an the sham kidney cortex. Relative to the sham kidney A2AAR and A2BAR mRNA expressions were also 2.6- and 2.0-fold increased, respectively. A3AR mRNA expression in the obstructed kidney cortex was also up-regulated by 3.3-fold. These data demonstrated that all 4 subtypes of AR were increased in the obstructed kidney, which was accompanied by tubulointerstitial fibrosis. Further studies are needed to determine which subtypes of AR play a protective or pathogenic role in tubulointerstitial fibrosis.

Stromal Cell-Derived Factor 1α Induces Accumulation of Intraveneously Administered Marrow-Derived Stromal Cells in the Partially Obstructed Rat Bladder.

We investigated the time course of the stromal cell-derived factor 1α (SDF1α) expression and behavior of intravenously administered bone marrow-derived stromal (BMS) cells in the urinary bladder of partial bladder outlet obstruction (PBOO) rats. Study 1: Recombinant SDF1α or saline was directly injected into the bladder wall of female rats followed by intravenous administration of BMS cells isolated from green fluorescent protein (GFP) transgenic rats. The bladder was examined with immunohistochemistry to determine whether SDF1α would enhance migration of BMS cells to the bladder. Study 2: Following surgery of PBOO or sham in female rats, bladders were removed on days 1-14, and expression of hypoxia inducible factor 1α (HIF1α) and SDF1α were examined with real-time polymerase chain reaction (PCR) to determine if PBOO preferentially increased their expression. Study 3: Female rats underwent PBOO or sham surgery followed by intravenous administration of GFP-positive BMS cells. Bladders were examined with immunohistochemistry on days 1-14 to determine whether BMS cells preferentially accumulated in the bladder. BMS cells were accumulated in the injection site of SDF1α but not saline in the bladder. SDF1α and HIF1α increased at day 1 after PBOO compared to sham. More BMS cells accumulated in the bladder of PBOO on day 1, and some BMS cells expressed smooth muscle phenotypes by day 14. SDF1α induced with ischemia/hypoxia due to PBOO is implicated in the accumulation of BMS cells in the bladder and regeneration of the bladder for PBOO.

115 SPONTANEOUS PERISTALTIC IN VIVO URETER ACTIVITY IS ALTERED IN RATS WITH PARTIAL URETHRAL OBSTRUCTION

INTRODUCTION AND OBJECTIVES: Some evidence suggests that benign prostatic hyperplasia (BPH) is associated with chronic renal failure (CRF). Risk factors for CRF in BPH are upper urinary tract dilation, recurrent urinary tract infection and secondary hypertension. This study analyzed the impact of partial urethral obstruction (PUO) on ureteral peristaltic function and intraureteral pressures in vivo in rats. METHODS: After Ethics Committee approval, 13 female Sprague Dawley rats (250-300 gram) were subjected to PUO. Ten days after surgery, under isofluran anesthesia, the left ureter was cannulated beneath the kidney pelvis with a polyethylene (PE)-10 catheter. To study the functional capacity of the ureter saline was infused at different speed (0.2 to 0.8 ml/hour). Data were recorded via a Grass polygraph and a Biopac system. The degree of obstruction was stratified according to bladder weight. T-test and correlation analyses were used for statistical comparison between obstructed and non-obstructed rats (controls; n 7). RESULTS: Bladder weights were 96 6mg (range 73-119mg; controls) and 557 6mg (range 338-961mg; PUO). At any infusion rate, the frequencies of spontaneous pressure waves were lower (p 0.0010.05) in PUO rats (range 2.28-2.88 waves/min) than in controls (range 5.16-5.76 waves/min). The maximal intraureteral pressure was lower (p 0.001-0.05 versus control) in PUO rats and amounted to 18.2 2.9 (0.2ml/h), 24.2 1.8 (0.4ml/h), 31.9 2.2 (0.6ml/h), 37.7 2.1 cmH2O (0.8ml/h). Corresponding values for controls were 32.6 3.5 (0.2ml/h), 38.9 3.3 (0.4ml/h), 41.9 4.9 (0.6ml/h), 46.9 4.5 cmH2O (0.8ml/h). The amplitude of intraureteral pressure waves were 9.4 2.3 (0.2ml/h), 10.4 1.7 (0.4ml/h), 12.8 2.2 (0.6ml/h), 13.5 2 cmH2O (0.8ml/h) for PUO rats. In controls (p 0.01-0.05), amplitudes were 18.3 2.8 (0.2ml/ h), 18.2 2.3 (0.4ml/h), 18.9 2.2 (0.6ml/h), 19.2 2.4 cmH2O (0.8ml/h). At infusion rates equal to or below 0.4ml/h, minimal intraureteral pressure and the area under the pressure curve were lower (p 0.05) in PUO rats than controls. Increased bladder weight was correlated to decreased amplitudes and lower frequency of spontaneous peristaltic ureter pressure waves at all infusion rates. At infusion rates equal to or below 0.4ml/h, bladder weight was also correlated to lower maximal intraureteral pressures. CONCLUSIONS: These results show that the peristaltic function of the ureter is significantly altered in rats with PUO and these changes are correlated to the degree of outflow obstruction.

2253 SILODOSIN EFFECTIVELY REDUCES PRESSURE OF THE OBSTRUCTED RAT URETER IN VIVO

You have accessJournal of UrologyStone Disease: Evaluation & Medical Management II1 Apr 20122253 SILODOSIN EFFECTIVELY REDUCES PRESSURE OF THE OBSTRUCTED RAT URETER IN VIVO Nicola Fossati, Luca Villa, Roberta Buono, Fabio Benigni, Francesco Montorsi, Patrizio Rigatti, and Petter Hedlund Nicola FossatiNicola Fossati Milan, Italy More articles by this author , Luca VillaLuca Villa Milan, Italy More articles by this author , Roberta BuonoRoberta Buono Milan, Italy More articles by this author , Fabio BenigniFabio Benigni Milan, Italy More articles by this author , Francesco MontorsiFrancesco Montorsi 20132, Italy More articles by this author , Patrizio RigattiPatrizio Rigatti 20132, Italy More articles by this author , and Petter HedlundPetter Hedlund Milan, Italy More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.2430AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Silodosin, a highly selective α1A-AR antagonist is proposed as a putative pharmacological expulsive therapy for ureter stones. The aim of the current study was to evaluate the effect of silodosin, tamsulosin and prazosin on intraureteral pressure and on blood pressure in an in vivo rat model for partial distal ureter obstruction. METHODS After ethical approval, 46 male Sprague Dawley rats (250-300 gram) were used. Under isofluran anaesthesia, saline was infused (0.4ml/hour = normal urine production in a rat) via a polyethylene (PE)-10 catheter in the left ureter beneath the kidney pelvis. The psoas muscle was sutured around the distal ureter to create a partial obstruction. The carotid artery and femoral vein were cannulated for registration of mean arterial blood pressure (MAP) and for administration of drugs. Data were recorded via a Polygraph and a Biopac system. Approximately corresponding to therapeutic and triple doses in humans, silodosin (0.1 or 0.3 mg/kg), tamsulosin (0.01 or 0.03 mg/kg), or prazosin (0.03 or 0.1 mg/kg) were given intravenously. Values are given as mean standard error of the mean. RESULTS In rats at baseline before obstruction, spontaneous peristaltic ureter pressure waves were recorded with minimum and maximum pressures of 19.7±0.7 and 37.8±1.3cmH2O, respectively. Obstruction increased minimum and maximum pressures to 43.7±1.6 and 58.6±1.7 cmH2O but had no effect on MAP that amounted to 124±3 cmH2O. Silodosin 0.1 and 0.3mg/kg reduced the minimum pressure after obstruction by 22±7 and 19±3%, respectively. Corresponding effects by tamsulosin 0.01 and 0.03mg/kg were 10±2% and 15±3% and prazosin 0.03 and 0.1mg/kg were 20±4% and 17±5%. Maximum pressure was reduced by 24±5% and 33±5% by silodosin (0.1 and 0.3mg/kg), 13±3% and 20±4% by tamsulosin (0.01 and 0.03mg/kg), and 14±4% and 21±4% by prazosin (0.03 and 0.1 mg/kg). Silodosin, tamsulosin, and prazosin reduced MAP by 11-12% (13-14cmH2O), 17-25% (21-37cmH2O; p<0.05 vs. silodosin), and 27-32% (31-39cmH2O; p<0.05 vs. silodosin). When expressed as a function of effects on MAP, silodosin was more effective (p<0.05) than tamsulosin or prazosin to reduce pressures of the rat obstructed ureter. Nerve-induced contractions of the isolated rat and human ureters were inhibited by all drugs (0.1-100μM). The order of efficacy in rat ureter was silodosin=prazosin>tamsulosin, and silodosin>prazosin=tamsulosin in human ureter. CONCLUSIONS Silodosin reduced pressure in vivo of the obstructed rat ureter with less effect on blood pressure than tamsulosin. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e909 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nicola Fossati Milan, Italy More articles by this author Luca Villa Milan, Italy More articles by this author Roberta Buono Milan, Italy More articles by this author Fabio Benigni Milan, Italy More articles by this author Francesco Montorsi 20132, Italy More articles by this author Patrizio Rigatti 20132, Italy More articles by this author Petter Hedlund Milan, Italy More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Impact of partial urethral obstruction on bladder function: time-dependent changes and functional correlates of altered expression of Ca2+ signaling regulators

In animal models of partial urethral obstruction (PUO), altered smooth muscle function/contractility may be linked to changes in molecules that regulate calcium signaling/sensitization. PUO was created in male rats, and urodynamic studies were conducted 2 and 6 wk post-PUO. Cystometric recordings were analyzed for the presence or absence of nonvoiding contractions [i.e., detrusor overactivity (DO)]. RT-PCR and Western blots were performed on a subpopulation of rats to study the relationship between the expression of RhoA, L-type Ca(2+) channels, Rho kinase-1, Rho kinase-2, inositol 1,4,5-trisphosphate, ryanodine receptor, sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 and protein kinase C (PKC)-potentiated phosphatase inhibitor of 17 kDa, and urodynamic findings in the same animal. Animals displayed DO at 2 (38%) and 6 wk (43%) post-PUO, increases were seen in in vivo pressures at 2 wk, and residual volume at 6 wk. Statistical analysis of RT-PCR and Western blot data at 2 wk, during the compensatory phase of detrusor hypertrophy, documented that expression of molecules that regulate calcium signaling and sensitization was consistently lower in obstructed rats without DO than those with DO or control rats. Among rats with DO at 2 wk, linear regression analysis revealed positive correlations between in vivo pressures and protein and mRNA expression of several regulatory molecules. At 6 wk, in the presence of overt signs of bladder decompensation, no clear or consistent alterations in expression of these same targets were observed at the protein level. These data extend prior work to suggest that molecular profiling of key regulatory molecules during the progression of PUO-mediated bladder dysfunction may shed new light on potential biomarkers and/or therapeutic targets.

Immunosuppression effects of bone marrow mesenchymal stem cells on renal interstitial injury in rats with unilateral ureteral obstruction

We investigated the effects of intravenously administered bone marrow mesenchymal stem cells (BMSCs) on renal interstitial inflammation and fibrosis. In unilateral ureteral obstruction (UUO) rats, the CD4+CD25+ regulatory T-cell (Treg) cell, macrophage population and some inflammation related cytokines were tested. In the BMSCs -treated rats, renal exhibited lower renal Masson scores, decreased macrophage infiltration and interferon gamma (IFNγ) expression, and increased forkhead transcription factor (Foxp3) and interleukin-10 (IL-10) expression. No significant differences in the CD4+CD25+ Treg population and renal transforming growth factor-β1 (TGFβ1) expression were observed between BMSCs-treated group and control group (p>0.05). In conclusion, BMSCs infusion leads to an anti-inflammation response in the early stage of UUO which may related to paracine mechanism.

107 Silodosin effectively reduces pressure of the obstructed rat ureter in vivo with limited effects on systemic blood pressure

107 Silodosin effectively reduces pressure of the obstructed rat ureter in vivo with limited effects on systemic blood pressure

Protective effects of thymoquinone against cholestatic oxidative stress and hepatic damage after biliary obstruction in rats

The aim of this study was to examine the preventive and therapeutic effects of thymoquinone (TQ) against cholestatic oxidative stress and liver damage in common bile duct ligated rats. A total of 24 male Sprague-Dawley rats were divided into three groups: control, bile duct ligation (BDL) and BDL + received TQ; each group contain 8 animals. The rats in TQ treated groups were given TQ (50 mg/kg body weight) once a day orally for 2 weeks starting 3 days prior to BDL operation. To date, no more biochemical and histopathological changes on common bile duct ligated rats by TQ treatment have been reported. The application of BDL clearly increased the tissue hydroxyproline (HP) content, malondialdehyde (MDA) levels and decreased the antioxidant enzyme [superoxide dismutase (SOD), glutathione peroxidase (GPx)] activities. TQ treatment significantly decreased the elevated tissue HP content, and MDA levels and raised the reduced of SOD, and GPx enzymes in the tissues. The changes demonstrating the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, mononuclear cells, and neutrophil infiltration into the widened portal areas were observed in BDL group. Treatment of BDL with TQ attenuated alterations in liver histology. The immunopositivity of alpha smooth muscle actin and proliferating cell nuclear antigen in BDL were observed to be reduced with the TQ treatment. The present study demonstrates that oral administration of TQ in bile duct ligated rats maintained antioxidant defenses and reduces liver oxidative damage and ductular proliferation. This effect of TQ may be useful in the preservation of liver function in cholestasis.

The role of autophagy in unilateral ureteral obstruction rat model

Autophagy is a cellular process of degradation of damaged cytoplasmic components and regulates cell death or proliferation. Unilateral ureteral obstruction (UUO) is a model of progressive renal fibrosis in the obstructed kidney. And UUO is followed by compensatory cellular proliferation in the contralateral kidney. We investigate the role of autophagy in the obstructed kidney and contralateral kidney after UUO. To obtain the evidence and the patterns of autophagy during UUO, the rats were sacrificed 3, 7 and 14 days after UUO. To examine the efficacy of the autophagy inhibitors, 3-methyladenine (3-MA), the rats were treated daily with intraperitoneal injection of 3-MA (30 mg/kg per day) for 7 days. After UUO, autophagy was induced in the obstructed kidney in a time-dependent manner. Inhibition of autophagy by 3-MA enhanced tubular cell apoptosis and tubulointerstitial fibrosis in the obstructed kidney after UUO. In the contralateral kidney, autophagy was also induced and prolonged during UUO. Inhibition of autophagy by 3-MA increased the protein expression of proliferating cell nuclear antigen significantly in the contralateral kidney after UUO. The Akt-mammalian target of rapamycin (mTOR) signalling pathway was involved in the induction of autophagy after UUO in both kidneys. Our present results support that autophagy induced by UUO has a renoprotective role in the obstructed kidney and regulatory role of compensatory cellular proliferation in the contralateral kidney through Akt-mTOR signalling pathway.

Association of PAX2 with Cell Apoptosis in Unilateral Ureteral Obstruction Rats

Renal interstitial fibrosis (RIF) is the final common pathway for chronic kidney disease. Cell apoptosis is a critical detrimental event that leads to renal fibrosis. Paired box 2 (PAX2) plays a major role in the development of the kidney. This study was performed to investigate whether PAX2 was associated with cell apoptosis in the progression of RIF in unilateral ureteral obstruction (UUO) rats. Eighty Wistar male rats were divided into two groups randomly: sham operation group (SHO) and model group subjected to UUO (GU), n = 40, respectively. The model was established by left ureteral ligation. Renal tissues were collected 14 and 28 days after surgery. Protein expressions of PAX2, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), collagen-IV (Col-IV), fibronectin (FN), and caspase-3 were detected using immunohistochemical analysis; mRNA expression of PAX2 in renal tissue was detected by real-time reverse transcription polymerase chain reaction; and RIF index and cell apoptosis index in renal interstitium were also calculated. When compared with those in the SHO group, expressions of PAX2 (protein and mRNA) were markedly increased in the GU group (each p < 0.01). Protein expressions of TGF-β1, α-SMA, Col-IV, FN, and caspase-3 and RIF index and cell apoptosis index in the GU group were remarkably increased when compared with those in the SHO group (each p < 0.01). The protein expression of PAX2 was positively correlated with the protein expressions of TGF-β1, α-SMA, Col-IV, FN, and caspase-3 and with RIF index and cell apoptosis index (all p < 0.01). The apoptotic cell in our observation was mainly derived from renal tubular epithelial cells. In conclusion, the increased expression of PAX2 is associated with cell apoptosis in the progression of RIF in UUO rats, suggesting that PAX2 is a potentially therapeutic target for prevention of RIF.Tian-Biao Zhou and Yuan-Han Qin wish it to be known that, in their opinion, they should be regarded as joint first authors.

Function of the Cold Receptor (TRPM8) Associated with Voiding Dysfunction in Bladder Outlet Obstruction in Rats

PurposeBladder outlet obstruction (BOO) causes storage and voiding dysfunction in the lower urinary tract. We investigated the expression of transient receptor potential cation channel subfamily M member 8 (TRPM8) to evaluate the relationship between TRPM8 expression and overactive bladder (OAB) in a rat model of BOO.MethodsFifty female Sprague-Dawley rats were divided into 4 groups; normal (n=10), normal-menthol (n=10), BOO (n=15), BOO-menthol (n=15). After 3 weeks, cystometry was performed by infusing physiological saline and menthol (3 mM) into the bladder at a slow infusion rate. The histological changes and expression of TRPM8 in the bladder were investigated by Masson's trichrome staining, immunofluorescence and reverse transcription-polymerase chain reaction.ResultsCystometry showed that the intercontraction interval (ICI; 428.2±23.4 vs. 880.4±51.2, P<0.001), micturition pressure (MP; 25.7±1.01 vs. 71.80±3.01, P<0.001), and threshold pressure (2.9±0.25 vs. 9.2±1.58, P<0.01) were significantly increased in BOO rats. The bladder wall was significantly dilated compared with the control. Detrusor muscle hypertrophy and a thick mucosa layer were observed in BOO bladder. After menthol treatment, ICIs were decreased and MPs were increased in the menthol treatment groups. TRPM8-positive cells and mRNA were predominantly increased in the bladder and dorsal root ganglia of all groups compared with the normal group.ConclusionsIncreased bladder wall thickness and proportion of collagen probably affect voiding dysfunction. Furthermore, an increase of TRPM8 expression in BOO may induce entry of Ca2+ from the extracellular space or stores. The increase of Ca2+ probably causes contraction of smooth muscle in BOO. However, OAB symptoms were not observed after menthol treatment although the expression of TRPM8 was abundant in the bladder epithelium after menthol treatment. Although OAB in BOO models may be caused by complex pathways, regulation of TRPM8 presents possibilities for OAB treatment.

The protective effects of metyrosine, lacidipine, clonidine, and moxonidine on kidney damage induced by unilateral ureteral obstruction in rats

To investigate the effects of metyrosine, lacidipine, clonidine, and moxonidine on the renal damage in rats with unilateral ureteral ligation by examining the histological evidence of parenchymal damage and tubular dilatation, as well as biochemical changes indicating cell membrane damage and DNA oxidation. Thirty-six albino Wistar rats were randomly divided into six equal groups: a healthy (intact) group, a unilateral ureteral ligation (control) group, and four drug treatment groups given metyrosine (50 mg/kg), lacidipine (2 mg/kg), clonidine (0.075 mg/kg), or moxonidine (0.2 mg/kg), respectively, for 10 days. The latter five groups underwent ligation of the left ureter. Ten days after the operation, we removed both kidneys from each rat in the control and drug treatment groups for renal pathological and biochemical [malondialdehyde (MDA), total glutathione, 8-hydroxy-2-deoxyguanine (8-OH-Gua)] examinations. Spectrophotometric assays were used to detect the malondialdehyde and total glutathione levels of the renal tissue. High-performance liquid chromatography was used to measure the 8-hydroxy-2-deoxyguanine levels. When the drug treatment groups were compared with the control group, the drug treatment groups' total glutathione level was higher and their malondialdehyde level was lower than that of the control group (P < 0.05), especially in the clonidine group (P < 0.0001). The 8-hydroxy-2-deoxyguanine levels of the drug treatment groups, except the lacidipine group, were significantly lower than that of the control group (P < 0.0001). There was no significant difference between the contralateral kidneys of the treatment groups and control group, according to the biochemical results. As revealed via light microscopy, clonidine and moxonidine treatment significantly reduced the tubular and glomerular damage, as well as the tubular dilation. The interstitial inflammation of the kidneys in the lacidipine group was higher than that of the other treatment groups. However, the apoptotic cell count was at a high level in both the lacidipine and metyrosine groups. The increase in the collagen content was most pronounced in the lacidipine and metyrosine groups. An examination of the contralateral kidneys showed no marked pathological findings. The use of a direct or indirect α2-adrenergic receptor agonist for the temporary treatment of unilateral ureteral obstruction-induced renal damage may be important for preventing renal structural injury. A more advanced study is necessary to determine the mechanisms underlying the protective effects of these drugs with regard to renal damage in ureteral obstruction.

Relaxant and contractile responses of detrusor muscle strips obtained from bladder outlet-obstructed rats treated with doxazosin enantiomers

(-)Doxazosin, one of (±)doxazosin enantiomers, was speculated to have a pharmacological enantioselectivity between the cardiovascular system and the urinary system by comparison with (+)doxazosin. Therefore, to evaluate the potential benefits of (-)doxazosin in the treatment of benign prostate hyperplasia, we compared the effects of the 3 agents, using rat mesenteric artery preparations and obstructed bladder strips. Concentration-response curves for carbachol (contractile response) and isoprenaline (relaxant response) in detrusor muscle strips of the bladder outlet obstruction (BOO) rats were shifted to the left, with significant increases in the Emax values, and significant decreases in the EC50 values by comparison with the sham-operated rats (P< 0.05, n = 10). The enhanced responses in detrusor muscle strips of the BOO rats treated with (±)doxazosin and its enantiomers at 3mg·(kg body mass)(-1)·day(-1) for 2weeks returned to normal levels, and the 3 agents inhibited the enhanced responses to carbachol and isoprenaline to the same extent. On the other hand, the 3 agents uncompetitively inhibited the vasoconstrictive response curves for NA in the rat isolated mesenteric artery, and the pKB value of (-)doxazosin at vascular α1-adrenoceptors was significantly smaller (P< 0.05, n = 6) than that of (+)doxazosin or (±)doxazosin. In conclusion, although (-)doxazosin inhibits vascular functional α1-adrenoceptors more weakly than (+)doxazosin, both agents equally ameliorate the enhanced responses in detrusor muscle of BOO rats, suggesting that the chiral carbon atom in the molecular structure of doxazosin does not affect its beneficial effects in the bladder smooth muscle of BOO rats.

Hepatic Arterial Perfusion Is Essential for the Spontaneous Recovery From Focal Hepatic Venous Outflow Obstruction in Rats

We previously observed that focal hepatic venous outflow obstruction recovered spontaneously by the formation of sinusoidal canals in a rat model of portal hyperperfusion. We aimed to investigate whether the lack of hepatic arterial perfusion aggravates parenchymal damage, decelerates recovery and influences the formation of sinusoidal canals after focal hepatic venous outflow obstruction. Rats were subjected to arterialized versus nonarterialized syngeneic liver transplantation after ligating the right median hepatic vein in the donor. Hepatic damage, microcirculation, regeneration and vascular remodeling were evaluated. In arterialized-recipients, confluent necrosis interspersed with viable periportal islands of hepatocytes, and vascularized sinusoidal canals with visible blood flow, surrounded by normal sinusoidal structure, were visible on postoperative day (POD) 2. Complete parenchymal recovery was consequently established by resorption of necrosis and hepatocyte proliferation, detected in viable portal islands and border zone. Lack of hepatic arterial perfusion caused complete necrosis in the obstruction zone without viable hepatocytes in the periportal area on POD2. Hepatocyte proliferation was only visible in the border zone. On POD28, perfused vascular structures, without neighboring normal sinusoidal structures, were observed in the scar-like area. Hepatic arterial perfusion determined the extent of hepatic necrosis, the formation of vascularized sinusoidal canals and the parenchymal recovery, after focal hepatic venous outflow obstruction.

Age-related changes in expression in renal AQPs in response to congenital, partial, unilateral ureteral obstruction in rats

Previously we demonstrated that neonatally induced partial unilateral ureteral obstruction (PUUO) in rats is associated with changes in the abundance of renal acid-base transporters that were paralleled by reduction in renal functions dependent on the severity and duration of obstruction. The aim of the present study was to identify whether changes in renal aquaporin abundance are age-dependent. Semiquantitative immunoblotting and immunohistochemistry were used to examine the changes in abundance of AQP1, AQP2, p-S256AQP2 (AQP2 phosphorylated at consensus site Ser256) and AQP3 in the kidneys of rats with neonatally induced PUUO within the first 48 h of life, and then monitored for 7 or 14 weeks. Protein abundance of AQP2 and AQP3 increased in both obstructed and non-obstructed kidneys 7 weeks after induction of neonatal PUUO (PUUO-7W). In contrast, AQP1 and AQP2 protein abundance in the obstructed kidney were reduced after 14 weeks of PUUO (PUUO-14W). Importantly, pS256-AQP2 protein abundance was reduced in obstructed kidneys of both PUUO-7W and PUUO-14W. Immunohistochemistry confirmed the persistent pS256-AQP2 downregulation in both PUUO-7W and PUUO-14W rats. The study shows that the protein abundance of AQP1, AQP2, and AQP3 in the obstructed kidney is increased in PUUO-7W, which may be a compensatory phenomenon and reduced in PUUO-14W rats suggesting a time-/age-dependent dysregulation in response to PUUO. pS256-AQP2 protein abundance is reduced consistent with obstruction-induced direct effects in the apical part of the collecting duct principal cells in response to PUUO.

Protective effect of sirolimus on water-electrolyte imbalance following bilateral ureteral obstruction in rats

Objective To explore the molecular mechanism of renal function defects after urinary obstruction and investigate the effect of sirolimus on the expression of γ-ENaC,Na + K + ATPase and AQP2,and its mechanism of renal Water-Electrolyte imbalance following bilateral ureteral obstruction (BUO) in rat kidneys.Methods Forty-eight rats were randomly divided into a sham operation group ( sham group),a BUO group,and a sirolimus treatment after BUO group.Bilateral ureters were exposed and occluded with ligature in the BUO and sirolimus treatment groups.Twenty-four hours later,the obstructed ureters were decompressed by removal of the ligature.The sham animal group underwent identical surgical procedures,but the ureter was simply dissected without removal of the ligature.The sirolimus treatment groups was given sirolimus intragastricly 0.4 ml per day (2 mg/kg · d) from the day before surgery until the rats were scari fled.The sham and BUO groups were given the same volume of intragastric saline.The urine and blood were collected at 4 d,7 d after surgery,and the functional data were observed.The expression of γ-ENaC,Na+K + ATPase and AQP2 were examined by immnohistochemistry and immunoblotting.Results On day four and seven post ureteral obstruction release,urine volume in the BUO group were (85.31 ± 13.15,66.39 ±10.56 ml),significantly higher than that of sham operation (35.36 ± 7.74,33.90 ± 8.03 ml) and sirolimus treatment groups (69.81 ± 10.70 ml,48.57 ± 9.01 ml) (P ＜ 0.05 ).Urine sodium concentrations in the BUO group were (42.17 ± 7.35 mmol/L,43.63 ± 18.39 mmoL/L),significantly lower than that of sham operation ( 170.56 ± 18.39 mmoL/L,172.52 ± 7.35 mmol/L) and sirolimus treatment groups (76.18 ± 13.20 mmol/L,134.28 ± 13.20 mmol/L),P ＜ 0.05.Immunoblotting assay showed that,on day four and seven post rats ureteral obstructions were released,integral optical density of γ-ENaC (2.09 ±0.32,2.27 ±0.35),Na+ K+ATP enzyme (2.41 ±0.48,2.67 ±0.43) and AQP2 (2.17 ±0.45,2.63 ±0.28) in the sirolimus treatment group were significantly higher than those of BUO group ( 1.28 ± 0.21,1.45 ±0.17) (1.99 ±0.28,2.18±0.24) (0.93 ±0.22,1.31 ±0.16),but still lower than the sham group (2.58±0.51,2.60±0.56) (2.89±0.53,2.97 ±0.66) (3.05 ±0.63,3.10±0.67).There were significant differences among all the three groups ( P ＜ 0.05 ).Conclusions The downregulation of γ-ENaC,Na + K + ATPase and AQP2 expression after BUO may contribute to the impaired renal tubular sodium reabsorption,decreased urinary concentration,and postobstructive polyuria.Sirolimus treatment significantly prevents impairment in renal function and also prevents downregulation of y-ENaC,Na + K+ ATPase and AQP2during BUO,demonstrating a marked renoprotective effect of sirolimus treatment in conditions with urinary tract obstruction. Key words: Sirolimus ; Water-electrolyte imbalance ; Animals, laboratory

Effect of Thymoquinone on Oxidative Stress in Escherichia coli–Induced Pyelonephritis in Rats

BackgroundRecurrent urinary tract infections are important in children and adults with diabetes mellitus and/or incontinence due to risk of pyelonephritis (PYN) and renal damage. There is a positive correlation released free radicals during PYN and renal damage. Experimental studies showed that antioxidant agents improve renal damage when used immediately after bacterial inoculation. ObjectiveThe aim of the present study was to evaluate whether treatment by thymoquinone (TQ) before or during Escherichia coli inoculation prevents oxidative damage in acute pyelonephritis (PYN) in an ascending obstructive rat model. MethodsIn this study, 42 Wistar rats were grouped as follows: control, PYN (24, 48, and 72 hours), and TQ-PYN (24, 48, and 72 hours). E. coli (1 ×109 colony forming units) was inoculated into the bladder via urethral catheterization in both the PYN and TQ groups. TQ injections were performed 24 hours before bacteria inoculation and repeated at 24-hour intervals during the indicated time at a dose of 10 mg/kg body weight intraperitoneally in TQ groups. ResultsSuperoxide dismutase activity was statistically lower in the TQ-PYN-48 and -72 groups than the PYN-48 and -72 groups (P < 0.001, P = 0.004, respectively). Catalase activity was significantly higher in PYN-24, -48, and -72 groups than the control group (P < 0.001). In addition, there was a significant difference between the TQ-PYN-24, -48, and -72 groups and PYN groups in terms of glutathione peroxidase activity (P < 0.001, P = 0.026, P = 0.046, respectively). When the TQ-PYN-72 group was compared with the PYN-72 group, malondialdehyde levels were significantly lower in the TQ-PYN-72 group than in the PYN-72 group (P = 0.033). A histologic examination also confirmed the protective effect of TQ. In statistical analysis of histopathologic findings, there were significant differences between the PYN-24 and TQ-PYN-24, PYN-48 and TQ-PYN-48, and PYN-72 and TQ-PYN-72 groups (P = 0.008, P < 0.001, P < 0.001, respectively). ConclusionsThe results indicate that TQ administration attenuated the oxidative damage that occurred in PYN and, therefore, could be used as a supportive agent to protect the kidneys from oxidative damage caused by PYN.

Hepatocyte Growth Factor (HGF) Inhibits Collagen I and IV Synthesis in Hepatic Stellate Cells by miRNA-29 Induction

BackgroundIn chronic liver disease, hepatic stellate cells (HSC) transdifferentiate into myofibroblasts, promoting extracellular matrix (ECM) synthesis and deposition. Stimulation of HSC by transforming growth factor-β (TGF-β) is a crucial event in liver fibrogenesis due to its impact on myofibroblastic transition and ECM induction. In contrast, hepatocyte growth factor (HGF), exerts antifibrotic activities. Recently, miR-29 has been reported to be involved in ECM synthesis. We therefore studied the influence of HGF and TGF-β on the miR-29 collagen axis in HSC.MethodologyHSC, isolated from rats, were characterized for HGF and Met receptor expression by Real-Time PCR and Western blotting during culture induced myofibroblastic transition. Then, the levels of TGF-β, HGF, collagen-I and -IV mRNA, in addition to miR-29a and miR-29b were determined after HGF and TGF-β stimulation of HSC or after experimental fibrosis induced by bile-duct obstruction in rats. The interaction of miR-29 with 3′-untranslated mRNA regions (UTR) was analyzed by reporter assays. The repressive effect of miR-29 on collagen synthesis was studied in HSC treated with miR-29-mimicks by Real-Time PCR and immunoblotting.Principal FindingsThe 3′-UTR of the collagen-1 and −4 subtypes were identified to bind miR-29. Hence, miR-29a/b overexpression in HSC resulted in a marked reduction of collagen-I and -IV synthesis. Conversely, a decrease in miR-29 levels is observed during collagen accumulation upon experimental fibrosis, in vivo, and after TGF-β stimulation of HSC, in vitro. Finally, we show that during myofibroblastic transition and TGF-β exposure the HGF-receptor, Met, is upregulated in HSC. Thus, whereas TGF-β stimulation leads to a reduction in miR-29 expression and de-repression of collagen synthesis, stimulation with HGF was definitely associated with highly elevated miR-29 levels and markedly repressed collagen-I and -IV synthesis.ConclusionsUpregulation of miRNA-29 by HGF and downregulation by TGF-β take part in the anti- or profibrogenic response of HSC, respectively.