endothelin-1 and Ureteral-Obstruction

To test the hypothesis that the gene expression of endothelin-1 and adrenomedullin may be altered in stenotic tissues of patients with congenital hydronephrosis caused by pelvi-ureteric junction (PUJ) obstruction.. Using real-time reverse transcription-polymerase chain reaction, mRNA of smooth muscle-constricting endothelin-1 and of smooth muscle-relaxing adrenomedullin was quantified in tissue specimens of 20 patients with PUJ obstruction (mean age 5.1 years, SD 7.0) and of 21 controls with normal PUJs (mean age 23.5 years, SD 24.2).. The amount of endothelin-1 mRNA in stenotic specimens was higher than in the controls, indicated by significantly lower threshold cycles (Ct values) in real-time PCR for the target gene in the obstructive tissue, with mean (SD) values of 24.9 (1.6) and 26.0 (2.1) (P < 0.05), respectively. The endothelin-1/CD31 ratio was significantly higher in the patients (P < 0.05) than in controls. In addition, adrenomedullin gene expression in the obstructed junctions was significantly lower than in normal junctions, with higher Ct values for the patient group of 26.7 (1.6) vs 25.2 (1.8) (P < 0.05) and lower adrenomedullin mRNA when standardized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (P < 0.05), CD31 (P < 0.01) and smooth muscle alpha-actin mRNA (P < 0.01). The two groups showed no significant differences for GAPDH and CD31 mRNA content, whereas there was about twice as much alpha-actin mRNA in stenotic tissues than in unaffected PUJs, shown by the lower Ct values for the patient group of 16.9 (2.0) vs 17.9 (2.6) (P < 0.05). Furthermore, endothelin-1, adrenomedullin and alpha-actin mRNA amounts were independent of age.. Taken together these results provide evidence that the production of autocrine/paracrine acting endothelin-1 and adrenomedullin is altered in tissues of patients with genuine PUJ obstruction, and may be involved in the pathogenesis of congenital hydronephrosis.

Topics: Adolescent; Adrenomedullin; Adult; Child; Child, Preschool; Endothelin-1; Gene Expression; Humans; Infant; Infant, Newborn; Peptides; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Ureteral Obstruction

Both endothelin-1 (ET-1) and the renin-angiotensin system (RAS) may play important roles in renal fibrosis in the obstructed kidney. However, there have been few clear demonstrations of a relationship between their activation and additive or synergistic roles in renal fibrosis. We investigated the protective roles and relationship between renal RAS and ET-1 in unilateral ureteral obstruction (UUO) mice.. 8-week-old male C57BL/6 mice were divided into seven groups: sham, bosentan+sham, valsartan+sham, vehicle+UUO, bosentan+UUO, valsartan+UUO, and valsartan+bosentan+UUO. Valsartan and bosentan were administered orally using an NG tube (valsartan 10 mg/kg/day, bosentan 100 mg/kg/day for 8 days, after which the molecular and structural kidney parameters were evaluated. Bosentan treatment elevated plasma renin activity, renal renin, and AT1R expression in UUO mice.. Although valsartan decreased plasma ET-1 in these mice, it did not affect ET(A) or ET(B) in their kidneys. Co-treatment with valsartan and bosentan decreased ET-1 in these mice compared to the single treatments. Bosentan, but not valsartan, elevated eNOS expression in their kidneys. Co-treatment with valsartan and bosentan reduced TGF-β, α-SMA, and collagen IV expression, and the Masson's trichrome stained area in their kidneys.. Bosentan and valsartan acted complementarily, and co-treatment with both drugs had an additive protective effect against renal fibrosis.

Topics: Acute Kidney Injury; Animals; Antihypertensive Agents; Bosentan; Drug Synergism; Endothelin-1; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Receptors, Angiotensin; Sulfonamides; Ureteral Obstruction; Valsartan

Antenatal hydronephrosis (AH) is found in 0.5%-1% of neonates. The aim of the study was to assess the urinary concentrations of 3 biomarkers, endothelin-1 (ET-1), monocyte chemotactic peptide-1 (MCP-1), and N-acetyl-glucosaminidase (NAG) in severely hydronephrotic neonates.. Neonates with a history of prenatal hydronephrosis were enrolled in the prospective study in 2 groups. Group 1 included neonates with severe forms of obstruction requiring surgical intervention and group 2 included neonates with milder forms of obstruction without any functional impairment. Fresh voided urinary levels of ET-1, MCP-1, and NAG were measured and their ratios to urinary Cr were calculated.. Fourty-two neonates were enrolled into the 2 groups: group 1, 24 patients (21 male, 3 female); group 2, 18 neonates (16 male, 2 female). There were no statistically significant differences between urinary ET-1, NAG, MCP-1 values, and ET-1/Cr and NAG/Cr ratios in groups 1 and 2. The urinary MCP-1/Cr ratio was significantly higher in group 1 than in group 2. For comparison of groups 1 and 2, the cut-off values were measured as 0.5709 ng/mg (sensitivity, 75%; specificity, 67%; positive predictive value [PPV], 71%; negative predictive value [NPV], 71%), 0.927 ng/mg (sensitivity, 77%; specificity, 72%; PPV, 77%; NPV, 72%), and 1.1913 IU/mg (sensitivity, 62%; specificity, 67%; PPV, 68%; NPV, 60%) for ET-1/Cr, MCP-1/Cr, and NAG/Cr ratios, respectively.. The urinary MCP-1/Cr ratio is significantly elevated in neonates with severe obstruction requiring surgical intervention. Based upon these results, urinary MCP-1/Cr may be useful in identification of severe obstructive hydronephrosis in neonates.

Topics: Acetylglucosaminidase; Biomarkers; Chemokine CCL2; Endothelin-1; Female; Humans; Hydronephrosis; Infant, Newborn; Male; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Ultrasonography; Ureteral Obstruction

To examine the role of voided urine endothelin-1 (ET-1) in the diagnosis and follow-up of children with ureteropelvic junction obstruction.. The study included 35 children with unilateral ureteropelvic junction obstruction who underwent pyeloplasty and 30 control children, including 10 healthy children, 10 with vesicoureteral reflux, and 10 with renal stones. Voided urine samples were obtained from the children in the study group before surgery and from the renal pelvis by needle aspiration during pyeloplasty. Bladder urine samples were also collected from the study group 1, 2, 3, 6, 9, and 12 months postoperatively. Bladder urine samples were also collected from all 30 control children. ET-1 was measured in the urine samples collected from the study and control groups.. The preoperative ET-1 level in the voided urine of the study group was significantly greater than its level in each of the three control groups. For the whole study group, a cutoff value of 3 fmol/mg creatinine gave a sensitivity of 74.3%, a specificity of 90%, and an overall accuracy of 81.5%. In 8 children (1 year old or younger), a cutoff value of 4 fmol/mg creatinine gave a sensitivity and specificity of 100%. Compared with the preoperative value, ET-1 had decreased significantly at 12 months after pyeloplasty.. The ET-1 level in voided urine is a useful marker that could be used as a noninvasive tool for the diagnosis and long-term follow-up of children with ureteropelvic junction obstruction.

Topics: Age Factors; Biomarkers; Child; Child, Preschool; Creatinine; Dilatation, Pathologic; Endothelin-1; Female; Humans; Infant; Kidney; Kidney Pelvis; Male; Prospective Studies; ROC Curve; Sensitivity and Specificity; Ureteral Obstruction

To investigate the expression of endothelin-1 (ET-1) and adrenomedullin (ADM) in the renal pelvis, stenotic ureteropelvic junction, and ureter of 20 male Wistar rats with congenital unilateral ureteropelvic junction obstruction; the normal contralateral kidneys served as controls. The molecular pathophysiology of congenital ureteropelvic junction obstruction is still unclear. The implication of altered peptidergic innervation is under discussion. Our study group has recently been able to demonstrate a significant increase in ET-1 and a significant decrease in ADM in prestenotic and stenotic tissue, but not in the remainder of the ureter, compared with controls.. Twenty animals were killed, and samples of the renal pelvis, ureteropelvic junction, upper ureter, middle part of the ureter, and lower ureter were immediately snap-frozen and stored in liquid nitrogen. Total RNA was extracted, and subsequently 1 microg of RNA was reversely transcribed. mRNA expression of ET-1 and ADM was determined semiquantitatively using on-line polymerase chain reaction. The expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was determined to relate the specific mRNA expression to the expression of a housekeeping gene.. We found a significant increase in the expression of ET-1 in the obstructed junctions related to GAPDH (P <0.001). The expression of ADM, however, revealed no statistically significant differences. No differences at all could be detected in the tissue samples from the rest of the ureter.. Alterations in the local production of peptidergic neurotransmitters, especially ET-1, may contribute to the molecular pathogenesis of ureteropelvic junction obstruction. Results previously obtained in the stenotic tissue from children were confirmed in the stenotic tissue from the rat model. We hypothesize that the alterations are disease-, but not age-specific.

Topics: Abnormalities, Multiple; Adrenomedullin; Animals; Atrophy; Computer Systems; Constriction, Pathologic; Disease Models, Animal; Endothelin-1; Gene Expression Profiling; Hydronephrosis; Kidney Pelvis; Male; Peptides; Polymerase Chain Reaction; Rats; Rats, Mutant Strains; Rats, Wistar; RNA, Messenger; Ureter; Ureteral Obstruction

To investigate the effects of nonselective endothelin receptor antagonist bosentan on the progression of renal interstitial fibrosis following unilateral ureteral obstruction (UUO).. Eighteen female SD rats were randomly divided into 3 groups: intervention group (administered with bosentan for 7 days after left ureter ligation), animal model group (administered with solution of Arabic gum for 7 days left ureter ligation) and sham operation group (administered with Arabic gum for 7 days after sham operation). Seven days after the operation the rats were killed and their left kidneys were harvested. The mRNA expressions of preproendothelin-1 (prepro ET-1), type I collagen (ColI), transforming growth factor beta1 (TGF-beta1), tissue inhibitors of metalloproteinase-1 (TIMP-1) and type 1 plasminogen activator inhibitor (PAI-1) were detected semiquantitatively with reverse transcription-polymerase chain reaction (RT-PCR). The protein expressions of endothelin-1 (ET-1), ColI, TGF-beta1, TIMP-1 and PAI-1were determined semiquantitatively by immunohistochemical staining assay.. The mRNA expressions of prepro ET-1, ColI, TGF-beta1, TIMP-1 and PAI-1 were significantly upregulated in obstructed renal tissue compared to those in sham operation group (all P < 0.05). The positive staining areas of ET-1, ColI, TGF-beta1, TIMP-1 and PAI-1 in tubulointerstitium were markedly enhanced in the animal model group in comparison with those in the sham operation group (all P < 0.05). The mRNA expressions of ColI, TGF-beta1 and TIMP-1 in renal tissue subjected to ureter ligation were significantly lower in the bosentan group then in the animal model group (all P < 0.05). The positive staining areas of ColI, TGF-beta1 and TIMP-1 in the tubulointerstitium were significantly smaller in bosentan group than in the animal model group (all P < 0.05). However, there was no significant difference in the mRNA expression of PAI-1 and in the positive staining area between the animal model group and bosentan group (both P > 0.05).. ET-1 may be involved in the progression of renal interstitial fibrosis following unilateral ureter ligation and blockage of its receptors with bosentan attenuates the fibroticlesion to a certain extent by possibly inhibiting TGF-beta1 and TIMP-1.

Topics: Animals; Bosentan; Collagen Type I; Endothelin-1; Female; Fibrosis; Kidney; Protective Agents; Rats; Rats, Sprague-Dawley; Sulfonamides; Tissue Inhibitor of Metalloproteinase-1; Ureteral Obstruction

Zinc (Zn) is an essential trace element in humans and animals. We have recently documented that Zn deficiency may aggravate tubulointerstitial nephropathy seen in the obstructed kidney (OK) of 72 hours duration through a further increase in the activity of endogenous angiotensin II in the OK. Also, it is known that the vasoconstrictors angiotensin II and endothelin (ET)-1 may be implicated in the deterioration of glomerular hemodynamics caused in the OK. We therefore designed the present study to examine the effect of Zn deficiency on the expression of ET-1 and a potential role of endogenous angiotensin II in the expression of ET-1 in glomeruli of the OK of 72 hours duration.. Using reverse transcription-polymerase chain reaction and immunohistochemistry, the expression of prepro-ET-1 mRNA and ET-1 was examined in glomeruli of the contralateral, non-obstructed control kidney (CLK) and the OK from rats with unilateral ureteral obstruction (UUO) of 72 hours duration fed a standard or a Zn-deficient diet for approximately 50 days. The rats in each group were treated with saline alone or the angiotensin-converting enzyme inhibitor enalapril before and after ureteral obstruction.. The expression of prepro-ET-1 mRNA and ET-1 was markedly greater in the OK than in the CLK in the standard and the Zn-deficient diet groups. However, the expression of prepro-ET-1 mRNA and ET-1 was substantially increased in the OK of the Zn-deficient diet group relative to the OK of the standard diet group. There were no significant differences in the expression of prepro-ET-1 mRNA and ET-1 between the CLK of the two diet groups. Administration of enalapril restored the expression of prepro-ET-1 mRNA and ET-1 in the OK to levels seen in the CLK in the standard and the Zn-deficient diet groups. Enalapril produced no effects on the expression of prepro-ET-1 mRNA and ET-1 in the CLK of the two diet groups.. UUO of 72 hours duration may increase the expression of prepro-ET-1 mRNA and ET-1 in glomeruli of the OK through an increment in the biological action of endogenous angiotensin II in the OK. Moreover, Zn deficiency may enhance the expression of prepro-ET-1 mRNA and ET-1 in glomeruli of the OK through a further increment in the biological action of endogenous angiotensin II in the OK. Zn deficiency appears to be a factor to worsen glomerular hemodynamics in the OK of the UUO setting of 72 hours duration through an increment in the biological action of the vasoconstrictors angiotensin II and ET-1.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Biomarkers; Copper; Enalapril; Endothelin-1; Endothelins; Female; Gene Expression; Immunohistochemistry; In Situ Hybridization; Kidney Glomerulus; Peptidyl-Dipeptidase A; Protein Precursors; Rats; Rats, Sprague-Dawley; Renin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Skin Diseases; Ureteral Obstruction; Zinc

In unilateral ureteral obstruction (UUO) vasoconstriction occurs both during and after release of UUO. ET-1, an endogenous peptide, causes marked vasoconstriction mediated by an increase in cytosolic calcium. We measured renal output of endothelin-1 (ET-1) in dogs with UUO and examined if the renal vasoconstriction that persisted after release of UUO could be reversed by a calcium antagonist, verapamil.. Hemodynamic and clearance experiments were performed in anesthetized mongrel dogs in three groups. Group I consisted of 9 dogs with sham-operation. Group 2 consisted of 7 dogs in whom ureteral obstruction was released 1.9 hours after UUO. Group 3 consisted of 5 dogs in whom verapamil was infused into the renal artery at two doses (5 and 10 microg./min., respectively) after release of UUO of 19-hour duration. ET-1 concentrations (measured by radioimmunoassay) were determined for renal venous and arterial plasma.. In Group 1 renal venous plasma ET-1 level was 16.7 +/- 2.2, significantly lowered than 22.8 +/- 3.2 pg./ml. in arterial plasma, indicating a net clearance of ET-1. In Group 2 and 3, renal venous plasma ET-1 levels (28.2 +/- 5.2 and 27.2 +/- 2.4 pg./ml., respectively) were significantly greater than those in arterial plasma (24.2 +/- 5.7 and 17.4 +/- 0.8 pg./ml., respectively), indicating a net output of ET-1 in the kidney, In addition, renal vasoconstriction occurred in Groups 2 and 3 as indicated by significantly lower renal blood flow and GFR than those in Group 1. In Group 3, intrarenal infusion of verapamil at two doses did not change arterial pressure but caused an ipsilateral, significant increase in RBF (from 132 +/- 4 17 to 1.84 +/- 19 and 180 +/- 16 ml./min., respectively) and dose-dependent increases in GFR (from 12 +/- 2 to 25 +/- 3 and 38 +/- 7 ml./min., respectively), associated with a profound dose-dependent ipsilateral diuresis and natriuresis.. Profound renal vasoconstriction in UUO was associated with an increase in renal production of ET-1, possibly contributing to renal vasoconstriction, and was reversed by intrarenal infusion of verapamil.

Topics: Animals; Blood Pressure; Dogs; Endothelin-1; Female; Regional Blood Flow; Ureteral Obstruction; Vasoconstriction; Vasodilator Agents; Verapamil