The combined effect of zinc oxide nanoparticles and milrinone on acute renal ischemia/reperfusion injury in rats: Potential underlying mechanisms.

AIM: To investigate the efficacy of zinc oxide nanoparticles (ZnO-NPs) and/or milrinone (MIL) on renal ischemia/reperfusion injury (I/RI) in rats and their possible underlying mechanisms. MATERIALS AND METHODS: Forty-eight adult male Sprague-Dawley albino rats were randomly assigned into six equal-sized groups (n = 8): normal control, sham-operated, I/R group (45 min/24 h), ZnO-NPs group (10 mg/kg i.p.), MIL group (0.5 mg/kg i.p.), and ZnO-NPs + MIL group in the same previous doses. KEY FINDINGS: In comparison to the I/R-operated group, administration of either ZnO-NPs or MIL significantly decreased serum creatinine and urea concentrations, and renal vascular permeability (p < 0.05). The oxidative stress was significantly declined, as evidenced by increased GPx, CAT, and SOD activities and decreased MDA and NO concentrations. Renal expressions of TNF-α, NF-κB, KIM-1, NGAL, and caspase-3 decreased significantly, while Nrf2 increased significantly. Histopathology investigation revealed improvement with minimal renal lesions and fibrosis after ZnO-NPs or MIL treatments. The combined treatments synergistically improved the studied parameters more than either treatment alone. These findings were validated by molecular modeling, which revealed that MIL inhibited TNF-α, NF-kB, caspase-3, KIM-1 and NGAL. SIGNIFICANCE: Both ZnO-NPs and MIL exerted cytoprotective effects against acute renal I/RI, and a combination of both was found to be even more effective. This renoprotective effect is suggested to be mediated through activation of Nrf2 and the prevention of the NF-κB activation-induced oxidative stress and inflammation, which may strengthen the potential role of ZnO-NPs or MIL in renal I/RI protection during surgical procedures.

Possible Underlying Mechanisms for the Renoprotective Effect of Retinoic Acid-Pretreated Wharton's Jelly Mesenchymal Stem Cells against Renal Ischemia/Reperfusion Injury.

Objectives: The current work investigated the effect of Wharton jelly mesenchymal stem cells (WJ-MSCs) pretreated with all-trans-retinoic acid (ATRA) on renal ischemia in rats and the possible role of oxidative stress, apoptotic and Wnt/ß-Catenin signaling pathways, and inflammatory cytokines in their effects. Methods: The study included 90 male Sprague Dawley rats that were allocated to five groups (n = 18 rats): (I) Sham-operated group (right nephrectomy was performed); (II) Ischemia/reperfusion injury (IRI) group, a sham group with 45-min renal ischemia on the left kidney; (III) ATRA group, an ischemic group with an intravenous (i.v.) administration of ATRA 10 µM, 10 min post-surgery); (IV) WJ-MSCs group, an IRI group with an i.v. administration of 150 µL containing 7 × 106 WJ-MSCs, 10 min post-surgery; (V) WJ-MSCs + ATRA group, an IRI group with an i.v. administration of 150 µL of 7 × 106 WJ-MSCs pretreated with 10 µM ATRA. At the end of the experiments, serum creatinine, BUN micro-albuminuria (MAU), urinary protein, markers of redox state in the left kidney (MDA, CAT, SOD, and GSH), and the expression of Bax, IL-6, HIF-1α, Wnt7B, and ß-catenin genes at the level of mRNA as well as for immunohistochemistry for NFkB and ß-Catenin markers were analyzed. Results: The current study found that 45-min of renal ischemia resulted in significant impairment of kidney function (evidenced by the increase in serum creatinine, BUN, and urinary proteins) and deterioration of the kidney morphology, which was associated with a significant increase in redox state (evidenced by an increase in MDA and a decrease in GSH, SOD, and CAT), and a significant increase in inflammatory and apoptotic processes (evidenced by an increase in Bax and IL-6, NFkB, Wnt7B, ß-catenin and HIF-1α) in kidney tissues (p < 0.05). On the other hand, treatment with ATRA, WJ-MSCs, or a combination of both, caused significant improvement in kidney function and morphology, which was associated with significant attenuation of oxidative stress, apoptotic markers, and inflammatory cytokines (IL6 and NFkB) with the upregulation of HIF-1α and ß-catenin in kidney tissues (p < 0.05). Moreover, the renoprotective effect of WJ-MSCs pretreated with ATRA was more potent than WJ-MSCs alone. Conclusions: It is concluded that preconditioning of WJ-MSCs with ATRA may enhance their renoprotective effect. This effect could be due to the upregulation of the beta-catenin/Wnt pathway and attenuation of apoptosis, inflammation, and oxidative stress.

Rapamycin Improves Adipose-Derived Mesenchymal Stem Cells (ADMSCs) Renoprotective Effect against Cisplatin-Induced Acute Nephrotoxicity in Rats by Inhibiting the mTOR/AKT Signaling Pathway.

OBJECTIVE: Because the poor survival of transplanted cells in a hostile microenvironment limits stem cell therapy, in the current study, we investigated the effect of rapamycin (Rapa)-preactivated autophagy on the survival and homing of transplanted adipose mesenchymal stem cells (ADMSCs) in a rat model of cisplatin (Cis)-induced nephrotoxicity, as well as the possible role of the mTOR/AKT signaling pathway. MATERIALS AND METHODS: In vitro, ADMSCs isolated from rats were treated with 50 nmol/L rapamycin for 2 h, after which the cytoprotective and autophagy-inducing effects of Rapa were investigated. The cis-induced acute nephrotoxicity rat model was constructed in vivo. ADMSCs and Rapa-ADMSCs were administered into the tail vein before Cis therapy. At 3, 7, and 10 days after Cis injection, all animals were euthanized. The renal functions and morphology as well as autophagy response were assessed. RESULTS: The pretreatment of cultured ADMSCs with Rapa caused a significant increase in autophagic activities and lysosome production of the cells, with a significant increase in the secretion of SDF-1, IL-10 and autophagy promoter LC3 and Beclin from these cells, while mTOR/AKT pathways were inhibited. In addition, the transplantation of Rapa-pretreated ADMSCs restored the kidney functions and morphology dramatically. Renal expression of SDF-1 and HIF1 was upregulated, while expression of IL-6, NF-kB and TGF-ß1 was downregulated. CONCLUSIONS: We concluded that the preactivation of autophagy with Rapa improves the survival and differentiation of the transplanted ADMSCs by inhibiting the mTOR/AKT signaling pathway, which in turn could significantly attenuate the Cis-induced acute renal injury.

Omega-3 polyunsaturated fatty acids: a modified approach for chemo-prevention of bladder cancer in a rat model and molecular studies of antineoplastic mechanisms.

OBJECTIVES: To test the chemo-preventative effects of omega-3 against bladder cancer (BC) induction in a rat model and its potential antineoplastic mechanisms. MATERIAL AND METHODS: Ninety male Fisher rats were divided into three groups during a 22-week protocol: group 1 (control), group 2 (Placebo + N-butyl-N-4- hydroxybutyl nitrosamine (BBN) for induction of BC and group 3 received omega-3 (1200 mg/kg/day) + BBN. At the end, blood samples and bladder tissues were collected and checked for the presence of malignancy, markers of angiogenesis (VEGF relative gene expression), inflammation (IL-6), proliferation (KI-67 expressions), oxidative stress (serum MDA and serum SOD) and epigenetic control (miRNA-145 level). RESULTS: At the end of the study, 60% and 86.6% rats survived in group 2 and 3 with significant weight loss among rats in group 2 when compared with other groups. In group 2, all rats developed visible bladder lesions of which five and 13 developed squamous cell carcinoma (SCC) and transitional cell carcinoma (TCC). In omega3-treated group, only one developed low grade SCC and one developed high grade non- invasive TCC. Bladders from omega-3-treated rats showed lower expression ofKI-67 (p < 0.05), VEGF (p < 0.001) and IL-6 (p < 0.001) and significant higher expression of mi-RNA (p < 0.001). Also, omega-3-treated group showed statistically significant lower MDA level (p < 0.001). CONCLUSION: Omega-3 inhibits bladder tumor growth in the BBN-induced BC rat model, due to anti-inflammatory, antioxidant, anti-proliferative, and anti-angiogenic properties together with epigenetic control.

Renoprotective effect of bone marrow mesenchymal stem cells with hyaluronic acid against adriamycin- induced kidney fibrosis via inhibition of Wnt/ß-catenin pathway.

AIM: The current study aimed to explore the pretreatment of bone marrow mesenchymal stem cells (BMSCs) with hyaluronic acid (HA) on renal fibrosis in Adriamycin- induced CKD in rats. MATERIAL AND METHODS: Sixty male SD rats were alienated into 4 equal groups; The control group: rats received two saline injections at 1 and 14 days, adriamycin (ADR) group: rats were injected i.v. twice via tail vein at day one and after 2 weeks, BMSCs group; rats were injected i.v. twice after 5 days of each ADR injection, and HA+BMSCs; rats were i.v. injected twice with BMSCs pretreated with 1 mg/ml HA after 5 days of each ADR injection. Protective role of BMSCs on renal function and morphology was detected using biochemical analysis, molecular studies, histopathological, and immunohistohemical investigations. RESULTS: Pretreatment of BMSCs with HA showed significant decrease in KIM-1, and increase in serum albumin compared to CKD group (p <0.05). Moreover, it reduced the expression of the apoptotic marker Caspase-3, the inflammatory markers TNF and IL-6, and the fibrotic markers Wnt7a, ß-catenin, and fibronectin1 than the CKD group (p < 0.05). CONCLUSION: The current outcomes suggested that BMSCs preconditioned with HA could attenuate the renal fibrosis in adriamycin- induced CKD.

Diacerein ameliorates kidney injury induced by cisplatin in rats by activation of Nrf2/Ho-1 pathway and Bax down-regulation.

Cisplatin is an antineoplastic medicine used for solid tumor treatment. The main side effect that limits its dose is nephrotoxicity. Diacerein has been used for the treatment of joint diseases like osteoarthritis. It also has exhibited analgesic effects and antipyretic activities in animal models so this study targets to indicate the diacerein effect on nephrotoxicity induced by cisplatin in rats. Rats were distributed into four groups: normal healthy control; diacerein, which received diacerein daily by gastric gavage (50 mg/kg/day); cisplatin, which received only one intraperitoneal injection of cisplatin (6 mg/kg) and cisplatin and diacerein, which received diacerein daily after the cisplatin injection till 7th and 12th days, respectively. Diacerein treatment decreased kidney function markers so the cisplatin effect was reversed. Also, diacerein increased the renal antioxidants and decreased oxidative stress. Diacerein up-regulated Ho-1 (heme oxygenase 1), Nrf2 (Nuclear factor erythroid 2-related factor 2) and endothelial nitric oxide synthase (eNOS) genes expression, while down-regulated Bcl-2-associated X protein (Bax) gene expression. Furthermore, the renal transforming growth factor beta-1 (TGF-ß1) decreased by the diacerein effect. Consequently, diacerein has a curative effect against cisplatin due to its anti-inflammatory, antioxidant, and antiapoptotic properties.

Possible mechanisms for the renoprotective action of adipose-derived mesenchymal stem cells with CD44-targeted hyaluronic acid against renal ischemia.

The present study aimed to investigate the invitro preconditioning of adipose-derived mesenchymal stem cells (ADMSCs) with CD44-targeted hyalournic acid (HA) on ischemic kidney injury in rats. Ninety male Sprague Dawley rats were randomly allocated into the following groups; i) sham group, ii) control group: rats exposed to 45 min left renal ischemia with saline treatment, iii) HA group as control group but rats treated with HA, iv) ADMSCs group as control but rats treated with ADMSCs v) HA + ADMSCs group as ADMSCs but rats treated with ADMSCs preconditioned with CD44-tageted HA for 14 days. We found that treattment with either ADMSCs or HA + ADMSCs caused significant decrease in the elevated serum creatinine and BUN and malondialdehyde (MDA) concentrations and expression of TGF-ß1, fibronectin, collagen type I, inducible nitric oxide synthease (iNOS) and microRNAs (miR-21, miR-17-5p, miR-10a) in kidney and significant increase in creatinine clearance, superoxide dismutase (SOD), reduced glutathione (GSH) and the expression of Bcl2, vascular endothelial growth factor (VEGF), Wnt/ß-catenin pathway genes in kidney compared to control group (p < 0.05). Moreover, HA + ADMSCs group caused more significant improvement in these parameters than ADMSCs group (p < 0.05), while HA group did not cause any significant improvement in these parameters compared to control group. These results suggest that preconditioning of ADMSCs preconditioned with CD44-targted HA enhanced their cytoprotective effect against ischemic kidney injury. This renoprotective effect might be due to activation of angiogenesis, Wnt/ß-catenin pathway proteins, and suppression of oxidative stress, apoptosis, inflammation and fibrosis.

Effect of low-energy shock wave therapy on intravesical epirubicin delivery in a rat model of bladder cancer.

OBJECTIVES: To study the efficacy of low-energy shock wave therapy (LESW) on enhancing intravesical epirubicin (EPI) delivery in a rat model of bladder cancer (BCa). MATERIALS AND METHODS: A total of 100 female Fischer rats were randomly allocated into five groups: control; BCa; LESW; EPI; and EPI plus LESW. After BCa induction by N-butyl-N-(4-hydroxybutyl)nitrosamine, EPI (0.6 mg/0.3 mL of EPI diluted in 0.3 mL saline) or saline (0.6 mL) was administered and retained in the bladders for 1 h with or without LESW treatment (300 pulses at 0.12 mJ/mm2 ). This was repeated weekly for 6 weeks. Survival was then calculated, rats were weighed and their bladders were harvested for bladder/body ratio estimation, histopathological examination, p53 immunostaining, miR-210, hypoxia-inducible factor (HIF)-1α, tumour necrosis factor (TNF)-α and interleukin (IL)-6 relative gene expression and fluorescence spectrophotometric drug quantification. Heart and blood samples were also collected for assessment of the safety profile and toxicity. RESULTS: The EPI plus LESW group had significantly lower mortality rates, loss of body weight and bladder/body ratio. Histopathological results in terms of grossly visible bladder lesions, mucosal thickness, dysplasia formation and tumour invasion were significantly better in the combined treatment group. The EPI plus LESW group also had statistically significant lower expression levels of p53 , miR-210, HIF-1α, TNF-α and IL-6. LESW increased urothelial concentration of EPI by 5.7-fold (P < 0.001). No laboratory variable exceeded the reference ranges in any of the groups. There was an improvement of the indicators of EPI-induced cardiomyopathy in terms of congestion, hyalinization and microvesicular steatosis of cardiomyocytes (P = 0.068, 0.003 and 0.046, respectively) in the EPI plus LESW group. CONCLUSIONS: The combined use of intravesical EPI and LESW results in less BCa invasion and less dysplasia formation, as LESW increases urothelial permeability of EPI and enhances its delivery into tumour tissues, without subsequent toxicity.

Protective role of zinc oxide nanoparticles in kidney injury induced by cisplatin in rats.

Cisplatin used as chemotherapy for various cancers may leads to accumulation of platinum within the kidney and disturb its function. Zinc oxide nanoparticles (ZnO-NPs) are of low toxicity nanomaterials and have many medical fields so this study aims to indicate ZnO-NPs effect in kidney injury induced by cisplatin. Adult male rats were pre-injected with one dose of ZnO-NPs (5 mg/kg IP) and after 2 h from injection, the rats were injected with also only one dose of cisplatin (6 mg/kg IP) and two additional groups were served as controls treated with either ZnO-NPs or cisplatin only, respectively, and normal control was involved and euthanization occurred after 7 and 12 days. Cisplatin-induced nephropathy increased kidney function parameters; serum creatinine, blood urea nitrogen and microalbuminuria. Conversely, these parameters were down regulated after ZnO-NPs treatment. ZnO-NPs reversed the decrease of renal superoxide dismutase, catalase and glutathione reductase and the increase of renal malondialdehyde induced by cisplatin. In addition, the annexin V demonstrated that the proportion of viable cells was significantly elevated and the proportion of apoptotic and necrotic cells significantly reduced. Also, the level of renal transforming growth factor beta 1 decreased in group pre-treated with ZnO-NPs. The Nuclear factor-E2-related factor, heme oxygenase-1 and endothelial nitric oxide synthase expression genes were up regulated while Bcl-2-associated X protein expression was down regulated in kidney tissue via ZnO-NPs. Histopathological and immunohistochemical observations were context with these findings. In conclusion, ZnO-NPs treatment revealed renoprotective effect against cisplatin drug, probably via its antioxidant, anti-inflammatory and antiapoptotic properties.

Preventive effect of pomegranate juice against chemically induced bladder cancer: An experimental study.

OBJECTIVES: Pomegranate juice (PJ) is rich in important compounds with anti-cancer activities. This study aims to investigate the preventive effect of pomegranate juice (PJ) against bladder cancer (BC). METHODS: Eighty male Sprague Dawley rats were randomly classified into 4 equal groups: (1) Normal controls; (2) PJ group: supplied by PJ for 12 weeks; (3) Cancer-induced group: intake 0.05% v/v N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for 8 weeks; (4) Cancer-prevented group: BBN + PJ. After 12 weeks, all rats were sacrificed and their urinary bladder tissues were subjected to histopathological and immunohistochemical (p53) examinations, expression of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), hypoxia-inducible factor 1 (HIF-1) and the tumor protein p53 (TP53) and analysis of oxidative stress markers. RESULTS: The development of BC was: 0/20 (0%) in normal, PJ and cancer-prevented groups and 20/20 (100%) in cancer-induced group. Significant neoplastic lesions were observed in cancer-induced group. Mild preneoplastic alterations were noticed in 25% (5/20) of cancer-prevented group. p53 immunostaining were significantly elevated in the cancer-induced group, which was decreased in the cancer-prevented group. The relative expressions of IL-6, TNF-α, HIF-1 and TP53 were significantly lower in the cancer-prevented group compared to the cancer-treated group. Correction in the oxidative stress markers were also observed in the cancer-prevented group. CONCLUSION: PJ possesses a promising inhibitory effect on BC development, probably due to its anti-oxidant and anti-inflammatory properties.

Low energy shock wave-delivered intravesical botulinum neurotoxin-A potentiates antioxidant genes and inhibits proinflammatory cytokines in rat model of overactive bladder.

PURPOSE: To study the effect of intravesical instillation of botulinum neurotoxin-A (BoNT-A) combined with low energy shock wave (LESW) for treatment of overactive bladder (OAB) in a rat model and to investigate its effect on the associated inflammatory and oxidative stress process. MATERIAL AND METHODS: Forty rats were subdivided into four equal groups: normal control group, OAB group, LESW group, and BoNT-A plus LESW group. Cystometrogram (CMG) changes and histopathological changes in the bladder mucosa were assessed in the different groups. Oxidative stress markers (malondialdehyde [MDA] and superoxide dismutase [SOD]) and proinflammatory cytokines (tumor necrotic factor-α [TNF-α] and interleukin-6 [IL-6]) were compared among groups. RESULTS: BoNT-A plus LESW group showed statistically significant lower amplitude (p = .001) and lower frequency of detrusor contractions (p = .01) compared to LESW, which showed no statistically significant difference in comparison to the OAB group. Also, the combined group significantly reduced submucosal edema and inflammatory cell infiltrate scores compared to all groups (p < .05). LESW was associated with 42% reduction of MDA expression while, LESW plus BoNT-A decreased it by 68% (p < .001). Also, LESW and LESW plus BoNT-A increased SOD expression by 43% and 75%, respectively (p < .001). LESW plus BoNT-A was associated with statistically significant lower expression of TNF-α and IL-6 expression by 37% and 66% in comparison to LESW group (p = .001). CONCLUSION: Intravesical instillation of BoNT-A plus LESW is an effective method for increasing the urothelial permeability to BoNT-A and enhancing its therapeutic effect against OAB in rat model through the expression of a substantial anti-inflammatory and antioxidative stress effect.

Renoprotective effect of local sildenafil administration in renal ischaemia-reperfusion injury: A randomised controlled canine study.

Objectives: To design a new canine model to assess the renoprotective effect of local sildenafil administration, as the renoprotective effect of systemic sildenafil administration in renal ischaemia-reperfusion (IR) injury in animal models has been shown but its local effects have not been established to date. Materials and methods: In all, 120 dogs were assigned to five groups: sham, oral control (OC) group (right nephrectomy + left renal ischaemia for 60 min), oral sildenafil (OS) group (oral sildenafil 1 mg/kg, 60 min before ischaemia), local control (LC) group (local renal perfusion with saline and heparin for 5 min) and local sildenafil (LS) group (perfusion with sildenafil 0.5 mg/kg). Renal functions, histopathological changes, expression of caspase-3, nuclear factor erythroid 2-related factor 2 (Nrf2), inflammatory cytokines (intracellular adhesion molecule 1, tumour necrosis factor α and interleukin 1ß) and endothelial nitric oxide synthase (eNOS) in renal tissues were assessed in all groups at 1, 3, 7 and 14 days. Results: There were significant improvements in renal functions and cortical and medullary damage scores in the sildenafil-treated groups compared to their control groups (P < 0.05). Also, the LS group showed significantly better improvement of renal functions and cortical and medullary damage scores than the OS group (P < 0.05). Moreover, sildenafil significantly decreased the expression of caspase-3 and inflammatory cytokines and increased the expression of Nrf2 and eNOS in renal tissue, which were statistically significant in the LS group. Conclusion: LS has a greater renoprotective effect against renal IR injury than systemic administration via anti-inflammatory, antioxidant and anti-apoptotic pathways. Abbreviations: BUN: blood urea nitrogen; Ct: cycle threshold; eNOS: endothelial nitric oxide synthase; GAPDH: glyceraldehyde 3-phosphate dehydrogenase; H&E: haematoxylin and eosin; IL-1ß: interleukin 1ß; NO: nitric oxide; Nrf2: nuclear factor erythroid 2-related factor 2; OC: oral control; OS: oral sildenafil; LC: local control; LS: local sildenafil.

Modulation of renal ischemia/reperfusion in rats by a combination of ischemic preconditioning and adipose-derived mesenchymal stem cells (ADMSCs).

The present study investigated the effects of combination of ischemic preconditioning (Ipre) and adipose-derived mesenchymal stem cells (ADMSCs) on renal ischemia-reperfusion (I-R) injury in rats. 90 male Sprague Dawley rats were divided into 5 equal groups; sham operated, control (45 min left renal ischemia), Ipre group as control group with 3 cycles of Ipre just before renal ischemia, ADMSCs-treated group (as control with ADMSCs 10(6) cells in 0.1 mL via penile vein 60 min before ischemia time), and Ipre + ADMSCs group as ADMCs group with 3 cycles of Ipre. Ipre and ADMSCs groups showed significant decrease in serum creatinine and blood urea nitrogen (BUN) and caspase-3 and CD45 expression in kidney and significant increase in HIF-1α, SDF-1α, CD31, and Ki67 expressions in kidney compared with the control group (p < 0.05). Moreover, the Ipre + ADMSCs group showed significant decrease in serum BUN and caspase-3 and CD45 expression in kidney with significant increase in HIF-1α, SDF-1α, CD31, and Ki67 expression in kidney compared with the Ipre and ADMCs groups (p < 0.05). We concluded that Ipre potentiates the renoprotective effect of ADMSCs against renal I/R injury probably by upregulation of HIF-1α, SDF-1α, CD31, and Ki67 and downregulation of caspase-3 and CD45.

Sildenafil activates antioxidant and antiapoptotic genes and inhibits proinflammatory cytokine genes in a rat model of renal ischemia/reperfusion injury.

OBJECTIVES: To study the possible renoprotective effect of sildenafil against renal ischemia/reperfusion (I/R) injury and its effect on the expression of some antioxidant, antiapoptotic gene and proinflammatory cytokine genes in rat model of renal I/R injury. MATERIALS AND METHODS: One hundred and twenty male Sprague Dawley rats were subdivided into three equal groups: sham (underwent right nephrectomy without ischemia), control (underwent right nephrectomy and left ischemia for 45 min) and study [as control with 1 mg/kg sildenafil (per oral) 60 min before anesthesia]. Serum creatinine and BUN were measured at the baseline and the study endpoints (2, 24, 48 h and 7 days), and the left kidney was harvested at study endpoints for histopathological examination as well as for assessment of the expression of antioxidant genes (Nrf-2, HO-1 and NQO-1), antiapoptotic gene (Bcl-2) and inflammatory cytokines, e.g., TNF-a, IL-1ß and ICAM-1. RESULTS: I/R caused significant increase in serum creatinine, BUN, histopathological damage score (p < 0.001) and significant reduction in antioxidant genes (nrf2, HO-1 and NQO-1) and antiapoptotic gene (Bcl2) with significant increase in TNF-a, IL-1ß and ICAM-1 genes in kidney tissues. Pretreatment with sildenafil caused significant attenuation of serum creatinine and BUN as well as significant increase in the expression of antioxidant genes and Bcl-2 genes with significant reduction in the expression of proinflammatory cytokine genes (p value < 0.001). CONCLUSION: The renoprotective effect of sildenafil against renal I/R might be due to the activation of antioxidant genes (Nrf2, HO-1 and NQO-1) and antiapoptotic gene (Bcl2) and attenuation of proinflammatory cytokines (TNF-a, IL-1ß and ICAM-1).

Is solitary kidney really more resistant to ischemia? An experimental canine study.

PURPOSE: To our knowledge there are no evidence-based medicine data to date to critically judge the vulnerability of a solitary kidney to warm ischemia compared to paired kidneys. MATERIALS AND METHODS: Ten dogs were exposed to open right nephrectomy to create a solitary kidney model (group 1). Ten dogs with both kidneys were considered group 2. All dogs underwent warm ischemia by open occlusion of the left renal artery for 90 minutes. Dogs were sacrificed at different intervals (3 days to 4 weeks). All dogs were reevaluated by renogram before sacrifice and histopathology of the investigated kidney. The proinflammatory markers CD95 and tumor necrosis factor-α were assessed using real-time polymerase chain reaction. RESULTS: In group 1 clearance decreased by 20% at 1 week but basal function was regained starting at week 2. In group 2 clearance decreased more than 90% up to week 2. Recovery started at week 3 and by 4 weeks there was a 23% clearance reduction. Histopathological examination in group 1 revealed significant tubular necrosis (60%) at 3 days with regeneration starting at 1 week. In group 2 there was more pronounced tubular necrosis (90%) with regeneration starting at 2 weeks. The expression of proinflammatory markers was up-regulated in each group with higher, more sustained expression in group 2. CONCLUSIONS: Solitary kidney in a canine model is more resistant to ischemia than paired kidneys based on radiological, pathological and genetic evidence.

Systemic and renal haemodynamic changes in renal schemia/reperfusion injury: impact of erythropoietin.

The objective of this study was to investigate the effects of erythropoietin (EPO) on systemic and renal hemodynamics in a rat model of renal ischemic/reperfusion (I/R) injury. We used 30 male Sprague-Dawley rats distributed among the following 3 groups (10 rats per group): (i) the sham-operated group, (ii) the control group (I/R injury only), and (iii) the EPO-treated group (I/R injury with 1500 U EPO·(kg body mass)⁻¹ on day 0, and 500 U·kg⁻¹ on days 2 and 4 after ischemia). Renal function, arterial blood pressure (ABP), renal plasma flow (RPF), renal blood flow (RBF), and renal vascular resistance (RVR) were measured on days 1, 2, and 7 after ischemia. The expression of endothelial NO synthase (eNOS) and histopathology of kidney were evaluated on day 7. The contractility of aortic strips was recorded from the different groups. The results show that renal function and histopathology were significantly improved after treatment with EPO. Compared with the control group, the EPO-treated group showed a significant increase in RPF, RBF, haematocrite, ABP, eNOS expression, and a decrease in RVR (p < 0.05).The response of aortic strips to the relaxant effect of acetylcholine was improved in the EPO-treated group. In conclusion, treatment with EPO improves renal function and renal haemodynamics in renal I/R injury, and causes significant rise of ABP and haematocrite value.

Does the afferent tubular segment in an orthotopic bladder substitution compromise ureteric antireflux properties? An experimental study in dogs.

OBJECTIVE: To study the effects of a short ureter on renal function and histology in an orthotopic bladder substitution model using a long afferent limb, in a canine model. MATERIALS AND METHODS: The study included nine adult mongrel dogs. A 40-cm segment of ileum was isolated, the distal half detubularized, configured into a U-shape and sutured to form a flat plate; this was then used to augment the bladder. The proximal half of the isolated ileum remained in continuity with the enterocystoplasty to form an isoperistaltic ileal 'chimney'. The left ureter was divided at its lumbar part and anastomosed to the chimney using a refluxing end-to-side Nesbit technique. The contralateral ureter was divided at its lower end and then anastomosed directly to the augmented segment of the bladder in a similarly refluxing manner to act as a control. The assessment after surgery included biochemical studies, ascending cystography, intravenous urography (IVU) and radioisotope renography at 6 weeks. The last two methods were repeated at intervals of 3 and 6 months after surgery. Urine culture was obtained and both kidneys were examined histopathologically at 6 months. RESULTS: The biochemical values assessed in all dogs were comparable to those before surgery. The urine culture obtained from the augmented bladders showed significant bacterial growth in all dogs. IVU at all follow-up sample times showed a normal configuration of both kidneys. Ascending cystography showed reflux in four of nine dogs on the right and six on the left side. There was a progressive decrease in the mean selective renographic clearance values of each of the right and left kidneys at intervals of 6 weeks, 3 and 6 months. The mean percentage reduction of renographic clearance was significantly higher in the left kidneys at 6 weeks and 3 months. Histopathological examination showed evidence of interstitial nephritis in all nine dogs and pyelonephritis in four of the left kidneys, while none of the right kidneys showed evidence of inflammation. CONCLUSION: Adequate peristalsis in a healthy long ureter is superior to the ileal segment substitution for protecting the kidney tissue against inflammation in the absence of an anatomical antireflux mechanism.

Cell-seeded tubular acellular matrix for replacing a long circumferential urethral defect in a canine model: Is it clinically applicable?

OBJECTIVE: To evaluate the feasibility of replacing a relatively long segment of the canine urethra by a tube of cell-seeded acellular collagen bladder matrix. MATERIALS AND METHODS: The study included 14 female mongrel dogs in which a 3-cm segment of the whole urethral circumference was excised and replaced by a tube of acellular matrix seeded with autologous urothelial cells. The acellular matrix was obtained from the excised bladder of female donor dogs that were not included in the study. Autologous cells were obtained from the study dogs by open bladder biopsy, with subsequent in vitro expansion and cultivation. Urethroplasty was performed over a 16 F urethral catheter that was kept for 4 weeks. The dogs were killed humanely (one every week for 4 weeks and then one monthly for 10 months). After stent removal, retrograde urethrography was used each month in the living dogs. If retention occurred a urethrogram was taken and then the dog was killed humanely. All grafts from dogs were harvested and sent for histopathological examination. RESULTS: Exploration at 1, 2, 3 and 4 weeks showed progressive shrinkage in length, together with relative narrowing of the lumen. Three dogs developed retention within a week after stent removal and the other seven developed retention within 4 months. Retrograde urethrograms showed evidence of stricture and/or fistula at the graft site in all dogs. On exploration, grafts showed marked shrinkage (0.6-1.2 cm in length) with complete obliteration of their lumens. Histopathological examination showed extensive fibrosis of the matrix with no evident urothelial architecture. CONCLUSION: Cell-seeded acellular matrix tube is insufficient to replace a 3-cm circumferential urethral defect in dogs.

Recoverability of renal function after relief of chronic partial unilateral ureteric obstruction: The effect of an angiotensin-converting enzyme inhibitor (enalapril).

OBJECTIVES: We evaluated the effect of an angiotensin-converting enzyme inhibitor (enalapril) on renal function during and after the relief of partial unilateral ureteric obstruction (UUO). MATERIALS AND METHODS: Thirty-two male mongrel dogs were classified into three groups: sham (eight), control (12; left partial UUO + no medication) and study (12; left partial UUO + enalapril). Dogs in the study and control groups were subjected to 4 weeks of partial UUO. After that, the dogs were re-opened and subjected to Lich-Gregoir vesico-ureteric re-implantation, and were killed humanely by the end of the eighth week after relief of obstruction. The study and control groups were evaluated at baseline, after 4 weeks of obstruction and at 4 and 8 weeks after relief of obstruction, by measuring selective creatinine clearance (CCr), selective renographic clearance (RCr) and renal resistive index (RI). The sham group had sham surgery at 4 and 8 weeks and was evaluated as the other two groups. RESULTS: Sham surgery showed no significant effect on any of the evaluated variables. Compared with the control, enalapril offset the reductions of CCr and RCr by an extra 11% and 12% of the basal values by the end of the fourth week of obstruction, respectively. Moreover, compared with the control, enalapril enhanced the recovery of CCr by an extra 10% and of RCr by an extra 23% of the basal values at 8 weeks after relief of the 4-week obstruction. In addition, the increase in RI was significantly less in the enalapril group. CONCLUSION: Enalapril decreases the deterioration of renal function in partial UUO and enhances the recoverability of renal function after relief of obstruction.

Recoverability of renal function after relief of chronic partial unilateral ureteral obstruction: study of the effect of angiotensin receptor blocker (losartan).

OBJECTIVES: To evaluate the effect of angiotensin receptor blocker (losartan) on renal function during and after relief of partial unilateral ureteral obstruction (PUO). METHODS: A total of 32 male mongrel dogs were classified into 3 groups: sham (8), control (12; left PUO + no medications), and study (12; left PUO + losartan). Dogs of the study and control groups were subjected to 4 weeks of PUO. After that, they were reopened and subjected to Lich-Grigoir ureterovesical reimplantation and then were killed by the end of 32 weeks after relief of obstruction after being evaluated at basal condition; fourth week of obstruction; and at 4, 8, and 32 weeks after relief of obstruction by measurement of selective creatinine clearance (CCr), selective renographic clearance (RC), and renal resistive index. Sham group underwent sham surgery at 4 and 32 weeks and evaluated as the other 2 groups. RESULTS: Sham surgery showed no significant effect on any of the evaluated parameters. Compared with the control, losartan saved reduction in CCr by 11% and RC by 20% of the basal value by the end of the fourth week of obstruction, respectively. Moreover, compared with the control, losartan enhanced regain of CCr by 26% and RC by 26% also of the basal value at 32 weeks after relief of fourth week obstruction, respectively. In addition, the increase in renal resistive index was significantly less in the losartan group. CONCLUSION: Losartan decreases the deterioration of renal function in PUO and enhances recoverability of renal function after relief of obstruction.