enalapril and Ureteral-Obstruction

Chronic unilateral ureteral obstruction results in interstitial fibrosis of the affected kidney. Both an angiotensin-converting enzyme inhibitor, enalapril, and an angiotensin II receptor antagonist, SC-51316, ameliorate the increased production of extracellular matrix protein in the tubulointerstitium of the obstructed kidney. Blockade of angiotensin II synthesis or inability of angiotensin II to bind to its receptor lessened the increased levels of mRNA for transforming growth factor-beta and collagen IV found in the obstructed kidney of untreated rats. A monocyte/macrophage infiltration was present in the obstructed kidney of untreated rats or rats treated with the angiotensin II receptor antagonists. In contrast, this infiltrate was almost completely absent in the obstructed kidney of rats treated with enalapril. The reason for this different effect of enalapril compared with the angiotensin II receptor antagonist on the macrophage infiltrate seen in obstructive nephropathy has not been elucidated. We conclude that both an angiotensin-converting enzyme inhibitor (enalapril) and a receptor antagonist of angiotensin II ameliorate the tubulointerstitial fibrosis that follows complete unilateral ureteral obstruction in the rat. We suggest that an increased level of angiotensin II has a major role in the development of tubulointerstitial fibrosis following ureteral obstruction.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Collagen; Enalapril; Extracellular Matrix Proteins; Fibrosis; Kidney; Kidney Diseases; Kidney Tubules; Macrophages; Monocytes; Rats; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta; Triazoles; Ureteral Obstruction

To investigate the effect of Huangqi decoction on renal interstitial fibrosis and its association with the transforming growth factor-β1 (TGF-β1) / mitogen-activated protein kinase (MAPK) signaling pathway.. 120 C57/BL mice were randomly divided into six groups: sham group, Enalapril (20 mg/kg) group, 5/6 nephrectomy model group, and 5/6 nephrectomy model plus Huangqicoction (0.12, 0.36 and 1.08 g/kg respectively) groups. Detecting 24hours urinary protein, blood pressure, serum creatinine, urea nitrogen content changes. Periodic Acid-Schiff stain (PAS) and Masson's trichrome staining was used to observe the renal tissue pathological changes. Protein expression of TGF-β1, Phosphorylated P38 mitogen activated protein kinases (P-P38), Phosphorylated c-jun N-terminal kinase (P-JNK), Phosphorylated extracellular regulated proteinhnase (P-ERK), Fibroblast-specific protein-1 (FSP-1), Alpha smooth muscle actin (α-SMA), Type III collagen (Collagen III), Connective tissue growth factor (CTGF), Bcl-2 Assaciated X protein (Bax) and B cell lymphoma 2 (Bcl-2) were measured with western blot and immunohistochemical.. Both Huangqi decoction and Enalapril improved the kidney function, 24 h urinary protein and the fibrosis in 5/6 nephrectomy mice, Huangqi decoction downregulated the expressions of TGF-β1, FSP-1, α-SMA, Collagen III and CTGF in a dose-dependent manner, and it has a significant difference ( 0.01) compared with model group.Huangqi decoction downregulated the expressions of P-P38, P-JNK, P-ERK and Bcl-2 in a dose-dependent manner, while upregulated the expression of Bax.. The protective effect of Huangqi decoction for renal interstitial fibrosis in 5/6 nep-hrectomized mice the inhibition of Epithelial-Mesenchymal Transitions and downregulating the TGF-β1/ MAPK signaling pathway.

Topics: Animals; bcl-2-Associated X Protein; Drugs, Chinese Herbal; Enalapril; Fibrosis; Kidney; Kidney Diseases; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Nephrectomy; Signal Transduction; Transforming Growth Factor beta1; Ureteral Obstruction

This study aimed to investigate the mechanism of fluorofenidone (AKF-PD) in treating renal interstitial fibrosis in rats with unilateral urinary obstruction (UUO). Thirty-two male Sprague-Dawley rats were randomly divided into sham, UUO, UUO + enalapril, and UUO + AKF-PD groups. All rats, except sham, underwent left urethral obstruction surgery to establish the animal model. Rats were sacrificed 14 days after surgery, and serum was collected for renal function examination. Kidneys were collected to observe pathological changes. Immunohistochemistry was performed to assess collagen I (Col I) protein expression, and terminal deoxynucleotidyl transferase-mediated nick end-labeling staining to observe the apoptosis of renal tubular epithelial cells. The expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (Apaf-1), and C/EBP homologous protein (CHOP) proteins was evaluated by immunohistochemistry and western blot analysis. AKF-PD showed no significant effect on renal function in UUO rats. The pathological changes were alleviated significantly after enalapril or AKF-PD treatment, but with no significant differences between the two groups. Col I protein was overexpressed in the UUO group, which was inhibited by both enalapril and AKF-PD. The number of apoptotic renal tubular epithelial cells was much higher in the UUO group, and AKF-PD significantly inhibited epithelial cells apoptosis. The expression of FADD, Apaf-1, and CHOP proteins was significantly upregulated in the UUO group and downregulated by enalapril and AKF-PD. In conclusion, AKF-PD improved renal interstitial fibrosis by inhibiting apoptosis of renal tubular epithelial cells in rats with UUO.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Apoptosis; Apoptotic Protease-Activating Factor 1; Blood Urea Nitrogen; Collagen Type I; Creatinine; Disease Models, Animal; Enalapril; Epithelial Cells; Fas-Associated Death Domain Protein; Fibrosis; Kidney Diseases; Male; Pyridones; Random Allocation; Rats, Sprague-Dawley; Transcription Factor CHOP; Ureteral Obstruction

To observe the effect of enalapril on the apoptosis of renal tubular epithelial cells in renal interstitial fibrosis rats and to explore the mechanism of enalapril on renal interstitial fibrosis.
 Methods: Twenty-four SD male rats were randomly divided into a sham operation group, a model group and an enalapril group (n=8 in each group). The rats in the model group and the enalapril group underwent the operation of left urethral obstruction to establish the animal model of unilateral urethral obstruction (UUO). Fourteen days later after the operation, all rats were sacrificed and their obstructed kidneys were collected for HE and Masson staining to observe the pathological change of renal tissues. Terminal deoxynucleotidyl transferase-mediated (dUTP) nick end-labeling (TUNEL) staining was used to detect the apoptosis of renal tubular epithelial cells. Immunohistochemistry and Western blotting were used to detect the protein expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (APAF-1) and C/EBP homologous protein (CHOP).
 Results: Compared with the sham operation group, the renal interstitial injury index and renal interstitial fibrosis index were significantly increased in the model group (P<0.05). Compared with the model group, the renal interstitial injury index and renal interstitial fibrosis index were both significantly decreased in the enalapril group (P<0.05). Compared with the sham group, the apoptosis rate of renal tubular epithelial cells was increased in the model group (P<0.05); compared with the model group, the apoptosis rate of renal tubular epithelial cells was significantly reduced in the enalapril group (P<0.05). The protein levels of FADD, APAF-1 and CHOP in the model group were significantly elevated than those in the sham group (all P<0.05), which were reversed in presence of enalapril (all P<0.05). 
 Conclusion: Enalapril can alleviate renal interstitial fibrosis through inhibiting apoptosis of renal tubular epithelial cells in UUO rats.. 目的：观察依那普利对肾间质纤维化大鼠肾小管上皮细胞凋亡的影响，探讨依那普利抗肾间质纤维化的作用机制。方法：将24只SD雄性大鼠随机分为假手术组(n=8)、模型组(n=8)和依那普利治疗组(n=8)。对模型组和依那普利治疗组大鼠行左侧输尿管结扎术，建立单侧输尿管梗阻(unilateral urethral obstruction，UUO)模型。术后14 d处死大鼠，留取梗阻侧肾组织分别进行HE和Masson染色，观察各组大鼠肾组织病理改变，用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法[terminal deoxynucleotidyl transferase-mediated (dUTP) nick end-labeling，TUNEL]染色检查肾小管上皮细胞凋亡，免疫组织化学及蛋白质印迹法检测Fas相关死亡结构域(Fas-associated death domain，FADD)、凋亡蛋白酶活化因子-1(apoptotic protease activating factor-1，APAF-1)、C/EBP同源蛋白(C/EBP homologous protein，CHOP)的蛋白表达。结果：HE染色、Masson染色显示模型组肾间质损伤指数、肾间质纤维化指数均较假手术组明显增高(均P<0.05)，依那普利治疗组肾间质损伤指数、肾间质纤维化指数均较模型组明显降低(均P<0.05)。TUNEL染色显示模型组肾小管上皮细胞凋亡计数较假手术组明显增多(P<0.05)，依那普利治疗组肾小管上皮细胞凋亡数较模型组明显减少(P<0.05)。免疫组织化学及蛋白质印迹法显示模型组肾组织FADD，APAF-1和CHOP的蛋白表达均较假手术组明显增多(均P<0.05)，依那普利治疗组肾组织FADD，APAF-1和CHOP的蛋白表达均较模型组明显降低(均P<0.05)。结论：依那普利可通过抑制UUO大鼠的肾小管上皮细胞凋亡而起到抑制肾间质纤维化的作用。.

Topics: Animals; Apoptosis; Enalapril; Epithelial Cells; Fibrosis; Kidney Tubules; Male; Rats; Ureteral Obstruction

Cardiovascular disease constitutes the leading cause of mortality in patients with chronic kidney disease (CKD) and end-stage renal disease. Despite increasing recognition of a close interplay between kidney dysfunction and cardiovascular disease, termed cardiorenal syndrome (CRS), the underlying mechanisms of CRS remain poorly understood. Here we report the development of pathological cardiac hypertrophy and fibrosis in early stage non-uremic CKD. Moderate kidney failure was induced three weeks after unilateral urinary obstruction (UUO) in mice. We observed pathological cardiac hypertrophy and increased fibrosis in UUO-induced CKD (UUO/CKD) animals. Further analysis indicated that this cardiac fibrosis was associated with increased expression of transforming growth factor β (TGF-β) along with significant upregulation of Smad 2/3 signaling in the heart. Moreover early treatment of UUO/CKD animals with an angiotensin-converting-enzyme inhibitor (ACE I), Enalapril, significantly attenuated cardiac fibrosis. Enalapril antagonized activation of the TGF-β signaling pathway in the UUO/CKD heart. In summary our study demonstrates the presence of pathological cardiac hypertrophy and fibrosis in mice early in UUO-induced CKD, in association with early activation of the TGF-β/Smad signaling pathway. We also demonstrate the beneficial effect of ACE I in alleviating this early fibrogenic process in the heart in UUO/CKD animals.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Cardiomegaly; Enalapril; Fibrosis; Heart Ventricles; Hypertension; Male; Mice, Inbred C57BL; Organ Size; Renal Insufficiency, Chronic; Signal Transduction; Transforming Growth Factor beta; Up-Regulation; Ureteral Obstruction; Ventricular Remodeling

Renal interstitial fibrosis (IF) is an important pathologic manifestation of disease progression in a variety of chronic kidney diseases (CKD). However, the quantitative and reproducible analysis of IF remains a challenge, especially in experimental animal models of progressive IF. In this study, we compare traditional polarized Sirius Red morphometry (SRM) to novel Second Harmonic Generation (SHG)-based morphometry of unstained tissues for quantitative analysis of IF in the rat 5 day unilateral ureteral obstruction (UUO) model. To validate the specificity of SHG for detecting fibrillar collagen components in IF, co-localization studies for collagens type I, III, and IV were performed using IHC. In addition, we examined the correlation, dynamic range, sensitivity, and ability of polarized SRM and SHG-based morphometry to detect an anti-fibrotic effect of three different treatment regimens. Comparisons were made across three separate studies in which animals were treated with three mechanistically distinct pharmacologic agents: enalapril (ENA, 15, 30, 60 mg/kg), mycophenolate mofetil (MMF, 2, 20 mg/kg) or the connective tissue growth factor (CTGF) neutralizing antibody, EX75606 (1, 3, 10 mg/kg). Our results demonstrate a strong co-localization of the SHG signal with fibrillar collagens I and III but not non-fibrillar collagen IV. Quantitative IF, calculated as percent cortical area of fibrosis, demonstrated similar response profile for both polarized SRM and SHG-based morphometry. The two methodologies exhibited a strong correlation across all three pharmacology studies (r2 = 0.89-0.96). However, compared with polarized SRM, SHG-based morphometry delivered a greater dynamic range and absolute magnitude of reduction of IF after treatment. In summary, we demonstrate that SHG-based morphometry in unstained kidney tissues is comparable to polarized SRM for quantitation of fibrillar collagens, but with an enhanced sensitivity to detect treatment-induced reductions in IF. Thus, performing SHG-based morphometry on unstained kidney tissue is a reliable alternative to traditional polarized SRM for quantitative analysis of IF.

Topics: Animals; Antibodies, Monoclonal; Azo Compounds; Collagen; Dose-Response Relationship, Drug; Enalapril; Fibrosis; Kidney Diseases; Male; Mycophenolic Acid; Non-Fibrillar Collagens; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Ureteral Obstruction

This study aimed to investigate renal arterial resistive index measurements and urine electrolytes before and after enalapril therapy in a rat model of unilateral ureteropelvic obstruction. The transforming growth factor (TGF)-β1 response of the renal tissue was also investigated.. 30 Wistar albino rats were randomly allocated into 5 groups (n=6). Group C rats served as controls. Group S rats had only laparotomy. Group E rats were only treated with enalapril. Rats in group UP and group UPE underwent laparotomy to create a left unilateral moderate partial obstruction. 2 weeks after establishing partial ureteropelvic junction obstruction, group UPE rats were treated with enalapril. Urine was collected over 24 h in all groups. Intrarenal arterial resistive index measurements were performed before and 2 weeks after surgery and after enalapril treatment in group UPE, and before and after enalapril treatment in group E. Rats were sacrificed by intracardiac puncture and left kidneys were harvested to evaluate levels of mRNA TGF-β1.. There was no significant difference in ARI values in group E. In group UPE, the difference between ARI values before and after surgery was statistically significant; the difference between ARI values after surgery and after enalapril treatment was also statistically significant. There was no statistically significant intra-group difference in urine electrolyte levels for UP group or UPE group. There was no difference in renal mRNA TGF-β1 levels.. Enalapril maintained renal blood flow by decreasing the arterial resistive index and maintained renal tubular function by protecting urine concentration and dilution ability in a rat model with unilateral ureteropelvic junction obstruction.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Disease Models, Animal; Electrolytes; Enalapril; Kidney; Rats; Rats, Wistar; Renal Artery; Renal Circulation; Transforming Growth Factor beta1; Ureteral Obstruction; Vascular Resistance

ACE inhibitors (ACEi) reduce renal tubulointerstitial fibrosis but are not completely effective. Combined extract of Astragalus membranaceus and Angelica sinensis (A&A) is a traditional antifibrotic agent in China. The present investigation aimed to determine whether an ACEi (Enalapril) and A&A together have a better antifibrotic effect in unilateral ureteral obstruction (UUO) than monotherapy with either agent. Male Sprague-Dawley rats (N = 4 per group) had either sham operation or UUO alone, with A&A (combined aqueous and ethanol extract equivalent to 2.1 g dried herbs), with Enalapril (in drinking water at 200 mg/mL) or with both treatments. Kidney and liver were collected for protein extraction or fixed for histologic stains, immunohistochemistry (IHC), microscopy. Enalapril or A&A individually were antifibrotic. Transforming growth factor-beta1, fibroblast activation, collagen deposition, macrophage accumulation and tubular cell apoptosis were all decreased. The combination of the two drugs was significantly more effective than Enalapril alone in reducing tumor necrosis factor-alpha, collagen accumulation, activation of fibroblasts, and tubular cell apoptosis. In conclusion, Enalapril with A&A significantly decreased tubulointerstitial fibrosis to a greater extent than treatment with Enalapril alone. Further studies focusing on the isolation of the active constituents of A&A and the clinical application of the combination of ACEi plus A&A are warranted to determine the value of this treatment in humans.

Topics: Angelica sinensis; Angiotensin-Converting Enzyme Inhibitors; Animals; Apoptosis; Astragalus propinquus; Collagen; Drugs, Chinese Herbal; Enalapril; Fibroblasts; Fibrosis; Kidney Tubules; Macrophages; Male; Phytotherapy; Plant Extracts; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Ureteral Obstruction

To dynamically observe the effect of enalapril on the expression of transforming growth factor beta1 (TGF-beta1), connective tissue growth factor (CTGF), alpha-smooth muscle actin (alpha-SMA), and Smad7 in the obstructed kidney after unilateral ureteral obstruction (UUO) in rats, and to investigate the effect of enalapril on transdifferentiation of renal tubular epithelial cells.. The model rats were induced by ligating the left ureter. Male Sprague-Dawley (SD) rats were divided into a normal control (sham-surgery) group, a model group, and a treatment group (enalapril 10 mg/ (kg * d) by gastric gavage from 24 h before the obstruction day). Rats were sacrificed on day 3, 7, 14, 21 after UUO was initiated. Sections of the renal tissue were stained with hematoxylin and eosin stain, which were used for histological and morphometric studies of the pathological change of the obstructed kidney. Real-time PCR was performed to examine the expression of TGF-beta1 mRNA and CTGF mRNA, and Western blot was performed to examine the expression of Smad7, alpha-SMA, and CTGF in the obstructed kidney.. The score of renal interstitial lesion increased with the extension of obstruction. The expression of TGF-beta1 mRNA, CTGF mRNA, alpha-SMA and CTGF increased in the model group with the extension of obstruction; but Smad7 expression decreased. Compared with the UUO group,the degree of renal interstitial lesion and the expression of TGF-beta1 mRNA, CTGF mRNA, alpha-SMA and CTGF were decreased, but the expression of Smad7 increased in the treatment group. Enalapril could significantly decrease TGF-beta1 mRNA on day 3, 7, 14, 21 after UUO. Enalapril could significantly affect the expression of CTGF mRNA,alpha-SMA,CTGF and Smad7 on day 3, 7, 14 after UUO initiation.. Enalapril significantly alleviates renal interstitial fibrosis by suppressing the expression of TGF-beta1, CTGF and alpha-SMA, upregulating the expression of Smad7, and has better effect at early stage (within 14 days after the UUO).

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Connective Tissue Growth Factor; Enalapril; Fibrosis; Kidney Tubules; Male; Rats; Rats, Sprague-Dawley; Smad7 Protein; Transforming Growth Factor beta1; Ureteral Obstruction

To investigate the effect of enalapril on renal interstitial fibrosis in rats with unilateral ureteral obstruction(UUO).. UUO model was induced by ligating the left ureter in rats. Male Sprague-Dawley(SD) rats were randomly divided into a sham-operated group(n=16), a UUO model group(n=24), and an enalapril treated group(n=24). The rats were treated with 10 mg/kg.d by gastric gavage in the enalapril treated group from 24 h before the operation, and the rats were treated with the identical dose of normal saline in the other 2 groups. The rats were sacrificed at 3,7,14, and 21 days after UUO. Pathological changes of the renal tissue were observed by HE and Masson staining, the mRNA expression of collagen I (Col I) was detected by real-time PCR, and the protein expression of connective tissue growth factor (CTGF) was detected by Western blot.. The renal interstitial damage index, relative collagen area and the expression of Col I mRNA and CTGF in the renal tissues in the model group increased with the prolongation of obstruction. Enalapril significantly reduced the renal interstitial damage index and relative collagen area, and inhibted the expression of Col I mRNA and CTGF. There was significant difference on day 3,7,and 14 (P<0.05), but not on day 21 (P>0.05).. Enalapril significantly attenuates renal interstitial fibrosis by supressing the expression of Col I mRNA and CTGF.

Topics: Animals; Collagen Type I; Connective Tissue Growth Factor; Enalapril; Male; Nephritis, Interstitial; Nephrosclerosis; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Ureteral Obstruction

Congenital urinary tract obstruction is the most important cause of renal insufficiency in infants and children, and angiotensin-converting enzyme (ACE) inhibitors attenuate the progression of renal disease in adults. ACE inhibitors are increasingly utilized in children with progressive renal disease. Because angiotensin is necessary for normal renal development, we examined the effects of ACE inhibition both during and immediately following the period of postnatal nephrogenesis in the neonatal rat subjected to sham operation or partial unilateral ureteral obstruction (UUO) under general anesthesia within the first 48 h of life. Rats in group I received enalapril 30 mg/kg body wt (or vehicle) daily for the first 10 days, while in group II, the 10 days of treatment began 10 days after surgery. Kidneys were harvested at day 21 and analyzed for apoptosis (TUNEL), interstitial macrophages (ED-1 immunohistochemistry), myofibroblasts (alpha-smooth muscle actin), and collagen (Sirius red). Partial UUO delayed glomerular maturation and increased ipsilateral renal macrophage infiltration, alpha-smooth muscle actin and Sirius red staining. In group I, enalapril increased myofibroblast accumulation in sham-operated kidneys, but not in obstructed kidneys. In contrast, in group II, enalapril further increased macrophage, myofibroblast, and collagen accumulation following partial UUO. The relative abundance of components of the kallikrein-kinin system, measured by Western blot, was not altered by partial UUO in the 14- and 28-day-old rat. Thus, in contrast to its salutary effects at later ages, ACE inhibition can worsen injury to the partially obstructed kidney during renal maturation even after the completion of nephrogenesis.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Newborn; Apoptosis; Body Weight; Cell Movement; Collagen; Contraindications; Enalapril; Kidney; Kidney Cortex; Kidney Diseases; Kidney Glomerulus; Kidney Medulla; Kidney Pelvis; Kidney Tubules; Kininogens; Macrophages; Organ Size; Rats; Rats, Sprague-Dawley; Receptor, Bradykinin B2; Tissue Kallikreins; Ureteral Obstruction

In unilateral ureteral obstruction (UUO), the kidney is characterized by increased fibrosis and apoptosis. Both transforming growth factor-beta (TGF-beta) and ANG II have been implicated, and ANG II may mediate its effects through TGF-beta. Previous studies demonstrated amelioration of renal damage when either TGF-beta or ANG II has been individually targeted. In this study, we sought to determine whether combining 1D11 (monoclonal antibody to TGF-beta) and an ACE inhibitor, enalapril, would be more effective in UUO than either individual treatment, as has been shown in diabetic and glomerulonephritic models. Rats underwent UUO and were given either control monoclonal antibody, 1D11 or enalapril, or 1D11/enalapril combination, for 14 days. Kidneys were harvested and examined for fibrosis [trichrome; collagen (real-time PCR, Sircol assay) and fibroblast-specific protein expression (immunohistochemistry), apoptosis (TUNEL), macrophage infiltration (immunohistochemistry), and TGF-beta expression (real-time PCR and tubular localization with immunohistochemistry)]. UUO was found to induce fibrosis, apoptosis, macrophage infiltration, and TGF-beta expression in the obstructed kidney. Administration of either 1D11 or enalapril individually significantly decreased all these changes; when 1D11 and enalapril were combined, there was little additive effect, and the combination did not provide full protection against damage. The results demonstrate that, for the most part, combination therapy is not additive in UUO. This could be due to the continued presence of a physical obstruction or to biochemical differences between UUO and other renal disease models. Furthermore, it suggests that other targets may be amenable to pharmacological manipulation in UUO.

Topics: Animals; Antibodies, Monoclonal; Apoptosis; Collagen; Drug Therapy, Combination; Enalapril; Fibrosis; Immunohistochemistry; In Situ Nick-End Labeling; Kidney; Macrophage Activation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction

To investigate the expression of P21 in renal interstitial fibrosis rats and the effect of enalapril on it.. Sprague Dawley rats were randomly divided into 3 groups: a sham operation group,a unilateral urethral obstruction group, and an enalapril treatment group. The expression of P21 in renal tubular epithelial cells on the process was detected by immunohistochemistry at different time spots (7, 14, 21 d after UUO, sham-surgery or enalapril treatment). The expression of p21 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR).. Seven days after the surgery, significant differences were found in P21 expression between UUO and SOR renal tubular cells. With degree of interstitial fibrosis aggravating, P21 expression increased. Enalapril can inhibit its expression.. In the kidney of UUO rats, P21 expression increased and enalapril possessed significant inhibitory effects on the procedure. P21 may participate in the pathogenesis of renal tubule-interstitial fibrosis.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Enalapril; Kidney Tubules; Male; Nephrosclerosis; Proto-Oncogene Proteins p21(ras); Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Ureteral Obstruction

To explore the effect of p27 in the renal tubule on the process of renal interstitial fibrosis caused by unilateral ureteral obstruction (UUO) in rats, and to examine the expression changes of p27 after enalapril intervention and to interpret the anti-fibrotic mechanism.. Ninety rats were randomly divided into the sham-operated group (SOR), UUO group,and UUO+enalapril treatment group [enalapril: 10 mg/(kg.d)]. The rats of each group were respectively sacrificed on 7, 14, 21 days post-operatively. The renal pathological changes were dynamically observed by HE. The expression and dynamic changes of p27 were detected by immunohistochemistry. The level of p27 mRNA were detected by RT-PCR.. The expression of p27 in renal tubular epithelial cells and p27 mRNA were strongly positive in the SOR group. With degree of interstitial fibrosis aggravating, the expression of p27 mRNA was gradually reducing. Enalapril could improve the expression of p27 on the 14th and 21st days after the UUO.. (1) This study supports a causative role of p27 in the formation of fibrosis of renal mesenchyme in rats with UUO. (2) The anti-fibrotic mechanism of enalapril is partly the improvement of p27 expression.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Cyclin-Dependent Kinase Inhibitor p27; Enalapril; Female; Kidney Tubules; Nephrosclerosis; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) could induce increased renal angiotensin II (ANG II), which enhances apoptosis of renal tubular cells and renal tissue loss. Systemic ANG II is also increased in UUO. There are no data available about whether UUO can induce apoptosis of circulating lymphocytes or not.. UUO or sham-operated male Wistar rats (n = 8 in each group) were fed a drinking solution containing water, angiotensin II receptor type 1 antagonist (ARA; losartan, 500 mg/L) or angiotensin-converting enzyme inhibitor (ACEI; enalapril: 200 mg/L) for 1 day or 7 days. Blood samples were collected and circulating lymphocyte cells were separated. The apoptotic cells were detected by in situ terminal deoxynucleotidyl transferase (TdT assay)-mediated digoxigenin/antidigoxigenin conjugated fluorescein method and counted under a fluorescence microscope. The apoptotic index was calculated.. UUO caused marked increases in the apoptotic index of circulating lymphocytes in UUO rats at both 1 day and 7 days when compared with the respective sham groups (P < 0.001). Neither ARA nor ACEI treatment had an effect on the apoptotic index values in the UUO rats at 1 day. In the UUO rats at 7 days, the apoptosis of circulating lymphocytes was markedly decreased from 29.2 +/- 2.7% to 11.9 +/- 2.7% (P < 0.01) in the ARA-treated rats and to 7.6 +/- 2.7% (P < 0.001) in the ACEI-treated rats.. UUO, via stimulation of ANG II, could promptly enhance apoptosis of circulating lymphocytes. The apoptosis persisted throughout the 7 days of the study. Prolonged UUO would impair lymphocyte cell immunity and the host defense mechanism. Continuous treatment with either ARA or ACEI could abrogate ANG II-stimulated circulating lymphocyte apoptosis.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Apoptosis; Enalapril; Leukocyte Count; Losartan; Lymphocytes; Male; Rats; Rats, Wistar; Ureteral Obstruction

Topics: Angiotensin-Converting Enzyme Inhibitors; Enalapril; Female; Humans; Kidney; Kidney Diseases; Male; Proteinuria; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) is a well-established model for the study of interstitial fibrosis in the kidney. It has been shown that the renin-angiotensin system plays a central role in the progression of interstitial fibrosis. Recent studies indicate that endothelin, a powerful vasoconstrictive peptide, may play an important role in some types of renal disease. To investigate the effects of angiotensin II on endothelin and its receptors in the kidney, mice were subjected to UUO and treated with or without enalapril, an orally active angiotensin-converting enzyme inhibitor, in their drinking water (100 mg/l). The animals were killed 5 days later. Using RT coupled with PCR, we measured the levels of endothelin-1, endothelin A, and endothelin B (ET(B)) along with transforming growth factor-beta, TNF-alpha, and collagen type IV mRNA expression in the kidney with UUO and the contralateral kidney along with interstitial expansion in the kidney cortex by a standard point counting method. We found that enalapril administration ameliorated the increased expression of ET-1 mRNA in the obstructed kidney by 44% (P < 0.02). Although the level of endothelin A mRNA expression was significantly increased in the obstructed kidney, it was not affected by enalapril. We found that enalapril treatment increased ET(B) mRNA expression by 115% (P < 0.05) and protein expression (measured by Western blot) in the kidney with an obstructed ureter. Enalapril treatment alone inhibited the expansion of interstitial volume due to UUO by 52%. Cotreatment with enalapril and the ET(B) receptor antagonist BQ-788 inhibited the expression of interstitial volume by only 19%. This study confirms that enalapril inhibits the interstitial fibrosis in UUO kidneys. It also suggests a beneficial and unforeseen effect of enalapril on the obstructed kidney by potentially stimulating the production of nitric oxide through an increased expression of the ET(B) receptor.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Enalapril; Female; Fibrosis; Gene Expression; Kidney; Mice; Mice, Inbred C57BL; Nitric Oxide; Receptor, Endothelin B; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) and hyperoxaluria (HOX) can lead to end-stage renal disease with tubulointerstitial fibrosis. We investigated the effects of enalapril (E), an ACE-inhibitor, on rat kidneys with either UUO or HOX. Sham-operated, UUO, HOX, UUO+HOX, UUO+E and HOX+E rats were killed 14 days after UUO and/or HOX was initiated. Rat kidney sections were histologically scored for tissue damage and monocyte/macrophage infiltration was demonstrated with ED1 antibody and measured by computer image analysis software. Serious glomerular and tubulointerstitial damage was found for UUO and HOX, consisting of glomerular basement membrane thickening, tubular dilatation/collapse, tubular basement membrane thickening and the infiltration of mononuclear leucocytes (mainly macrophages). For HOX, calcium oxalate crystals were visible. Neither the scored histological parameters nor monocyte/macrophage infiltration was significantly decreased when E-treated were compared with untreated groups. We conclude that E did not ameliorate the parameters scored in either UUO or HOX. This being contrary to findings by other research groups, we hypothesize that E may be effective only in short-term UUO/HOX, with transforming growth factor, TGF-beta1, formation becoming partly independent of Ang II in late-stage UUO/HOX, or other fibrogenic cytokines than TGF-beta1 becoming predominant.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Ectodysplasins; Enalapril; Hyperoxaluria; Immunohistochemistry; Kidney; Male; Membrane Proteins; Rats; Rats, Wistar; Ureteral Obstruction

Angiotensin II upregulates tumor necrosis factor-alpha (TNF-alpha) in the rat kidney with unilateral ureteral obstruction (UUO). In a mouse model of UUO, we found that tubulointerstitial fibrosis is blunted when the TNF-alpha receptor, TNFR1, is functionally knocked out. In this study, we used mutant mice with UUO in which the angiotensin II receptor AT(1a) or the TNF-alpha receptors TNFR1 and TNFR2 were knocked out to elucidate interactions between the two systems. The contribution of both systems to renal fibrosis was assessed by treating TNFR1/TNFR2-double knockout (KO) mice with an angiotensin-converting enzyme inhibitor, enalapril. The increased interstitial volume (Vv(int)) in the C57BI/6 wild-type mouse was decreased in the AT(1a) KO from 32.8 +/- 4.0 to 21.0 +/- 3.7% (P < 0.005) or in the TNFR1/TNFR2 KO to 22.3 +/- 2.1% (P < 0.005). The Vv(int) of the TNFR1/TNFR2 KO was further decreased to 15.2 +/- 3.7% (P < 0.01) by enalapril compared with no treatment. The induction of TNF-alpha mRNA and transforming growth factor-beta1 (TGF-beta1) mRNA in the kidney with UUO was significantly blunted in the AT(1a) or TNFR1/TNFR2 KO mice compared with the wild-type mice. Treatment of the TNFR1/TNFR2 KO mouse with enalapril reduced both TNF-alpha and TGF-beta1 mRNA and their proteins to near normal levels. Also, alpha-smooth muscle actin expression and myofibroblast proliferation were significantly inhibited in the AT(1a) or TNFR1/TNFR2 KO mice, and they were further inhibited in enalapril-treated TNFR1/TNFR2 KO mice. Incapacitating the angiotensin II or the TNF-alpha systems individually leads to partial blunting of fibrosis. Incapacitating both systems, by using a combination of genetic and pharmacological means, further inhibited interstitial fibrosis and tubule atrophy in obstructive nephropathy.

Topics: Actins; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Antigens, CD; Collagen; Enalapril; Enzyme-Linked Immunosorbent Assay; Fibrosis; Kidney; Lymphotoxin-alpha; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron; Muscle, Smooth; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Receptors, Tumor Necrosis Factor, Type II; RNA, Messenger; Tumor Necrosis Factor-alpha; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) is a model of renal injury characterized by progressive tubulointerstitial fibrosis and renal damage, while relatively sparing the glomerulus and not producing hypertension or abnormalities in lipid metabolism. Tubulointerstitial fibrosis is a major component of several kidney diseases associated with the progression to end-stage renal failure. Here we report that when a critical renal developmental morphogen, osteogenic protein-1 (OP-1; 100 or 300 microg/kg body wt), is administered at the time of UUO and every other day thereafter, interstitial inflammation and fibrogenesis are prevented, leading to preservation of renal function during the first 5 days after obstruction. Compared with angiotensin-converting enzyme inhibition with enalapril treatment, OP-1 was more effective in preventing tubulointerstitial fibrosis and in preserving renal function. The mechanism of OP-1- induced renal protection was associated with prevention of tubular atrophy, an effect not shared with enalapril, and was related to preservation of tubular epithelial integrity. OP-1 blocked the stimulation of epithelial cell apoptosis produced by UUO, which promoted maintenance of tubular epithelial integrity. OP-1 preserved renal blood flow (RBF) during UUO, but enalapril also stimulated RBF. Thus OP-1 treatment inhibited tubular epithelial disruption stimulated by the renal injury of UUO, preventing tubular atrophy and diminishing the activation of tubulointerstitial inflammation and fibrosis and preserving renal function.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Apoptosis; Atrophy; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Cell Size; Collagen; Enalapril; Epithelial Cells; Fibrosis; Immunohistochemistry; Inflammation; Kidney; Macrophages; Rats; Rats, Sprague-Dawley; Renal Circulation; Transforming Growth Factor beta; 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

Ureteral obstruction causes infiltration of the kidney by monocytes/macrophages. This infiltrate is significantly reduced by administration of an angiotensin-converting enzyme (ACE) inhibitor but not by a specific angiotensin II type 1 receptor (AT1 receptor) antagonist. Chemoattractants and cell surface adhesive molecules mediate monocyte/macrophage infiltration. Rats with unilateral ureteral obstruction (UUO) of 1, 3, or 5 days duration were untreated or given enalapril or SC-51316 in the drinking water. We measured the mRNA levels of monocyte chemoatactic peptide 1 (MCP-1), a chemoattractant, and levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), two cell surface adhesion proteins. MCP-1 mRNA increased significantly after 1 day of UUO and increased further through 5 days of UUO in the obstructed kidney. ICAM-1 mRNA also increased significantly after 1 day but steadily declined through 5 days of UUO in the obstructed kidney. VCAM-1 mRNA did not increase significantly until after 3 days of UUO and increased further through 5 days of obstruction. Enalapril or SC-51316 treatment had no significant effect on ICAM-1 mRNA levels. MCP-1 mRNA levels were reduced but remained significantly elevated. Enalapril significantly blunted the increase in VCAM-1 mRNA levels and VCAM-1 protein determined by immunocytochemistry; SC-51316 had no significant effect. Thus changes in VCAM-1 levels may account for the differential effect of enalapril and SC-51316 on monocyte/macrophage infiltration of the kidney during ureteral obstruction.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Cell Adhesion; Cell Adhesion Molecules; Chemokine CCL2; Enalapril; Female; Gene Expression Regulation; Immunohistochemistry; Intercellular Adhesion Molecule-1; Macrophages; Monocytes; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; RNA, Messenger; Tetrazoles; Triazoles; Ureteral Obstruction; Vascular Cell Adhesion Molecule-1

Osteopontin is a bone protein also expressed in other tissues. Increased osteopontin is thought to be associated with tissue inflammation. We used immunocytochemical analyses and polymerase chain reaction amplification of mRNA to examine osteopontin expression and regulation in unilateral ureteral obstruction (UUO) in rats, a model of inflammatory kidney disease. In the obstructed kidney, osteopontin mRNA and protein were significantly increased. The increase reached 4-fold after 1 day of UUO and persisted at this level for the 5-day duration of UUO. Immunocytochemical analyses showed increased osteopontin protein in tubular cells of the obstructed kidney cortex from days 1 through 5 of UUO. No such significant increase was apparent in the glomerulus or interstitium. Increased osteopontin mRNA and protein likewise occurred in the tubular cells of the obstructed kidney of rats that had undergone whole-body irradiation to eliminate macrophage infiltration into the experimental kidney. Purified osteopontin was found to be a chemoattractant for macrophages isolated from the rat peritoneum. Enalapril treatment, which decreases macrophage infiltration of the obstructed kidney, had no effect on the increase in osteopontin mRNA but significantly attenuated the increase in protein in tubular cells. Western blot analysis of whole cortical homogenates revealed that the osteopontin antibody recognized one protein of 67 kD. The amount of this protein was substantially decreased in kidney homogenates obtained from enalapril-treated compared to untreated animals. Increased osteopontin synthesis may, therefore, contribute in part to the inflammatory response that characterizes obstructive nephropathy.

Topics: Animals; Chemotactic Factors; Chemotaxis; Enalapril; Gene Expression; Immunohistochemistry; Kidney; Kidney Cortex; Kidney Glomerulus; Kinetics; Macrophages; Osteopontin; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sialoglycoproteins; Tissue Distribution; Ureteral Obstruction; Whole-Body Irradiation

The transcription factor nuclear factor kappa B (NF-kappa B) controls a number of genes associated with tissue inflammation and has been shown to be activated in the kidney with ureteral obstruction. In this investigation, we further explored NF-kappa B activation in the kidney cortex of rats with unilateral ureteral obstruction. Electrophoretic mobility shift assays combined with antibody supershift/depletion demonstrated that NF-kappa B subunits p50, p52, c-rel, p65 (RelA) and RelB were all activated. Immunocytochemical analysis using an antibody to the p50 subunit demonstrated activation occurring predominantly in nuclei of tubular cells. Treatment of animals with unilateral ureteral obstruction with an oral ACE inhibitor significantly decreased NF-kappa B activation. This suggests that the antiinflammatory effect of ACE inhibitors in renal disease is in part due to a blunting of NF-kappa B activation.

Topics: Administration, Oral; Angiotensin-Converting Enzyme Inhibitors; Animals; Enalapril; Enzyme Activation; Female; Immunohistochemistry; Kidney; NF-kappa B; Rats; Rats, Sprague-Dawley; Ureteral Obstruction

Tubulointerstitial fibrosis in unilateral ureteral obstruction (UUO) is driven by increased levels of angiotensin II (Ang II). In this study, we examined the time course of the fibrotic process in rats with UUO and explored the effect of delayed administration of an angiotensin converting enzyme (ACE) inhibitor, enalapril, on the tubulo-interstitial fibrosis of obstructive uropathy. Rats were sacrificed at 3, 5, 8, or 10 days after UUO was initiated. Some rats did not receive treatment, whereas others were treated with enalapril from day 4 to day 8 or from day 6 to day 10 after the onset of UUO. The levels of mRNA for transforming growth factor beta 1 (TGF-beta 1), collagen type IV (collagen IV), and tissue inhibitor of metalloproteinase (TIMP-1) were measured at each time point by reverse transcription-polymerase chain reaction (RT-PCR). The relative volume of the tubulointerstitium (Vv) was measured by a point-counting method. Monocyte/macrophage infiltration and collagen IV protein deposition were examined histologically using specific antibodies. There were significant increases in TGF-beta 1, TIMP-1, and collagen IV mRNAs in the obstructed kidney. Treatment with enalapril on day 4 through day 8 or on day 6 through day 10 significantly reduced the elevated mRNA levels of these compounds in the obstructed kidney. Histological studies showed augmented Vv, monocyte/macrophage infiltration, interstitial alpha-smooth muscle actin expression, and collagen IV protein deposition on days 3, 5, 8, or 10 of UUO; enalapril treatment from day 4 to 8 or from day 6 to 10 halted and to an extent reversed these increases. These data suggest that enalapril administration after several days of UUO is an effective means of preventing the progression of tubulointerstitial fibrosis of obstructive uropathy.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Base Sequence; Collagen; Enalapril; Female; Fibroblasts; Fibrosis; Glycoproteins; Immunohistochemistry; Macrophages; Molecular Sequence Data; Muscle, Smooth; Nephritis, Interstitial; Polymerase Chain Reaction; Protease Inhibitors; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta; Ureteral Obstruction

Angiotensin-converting enzyme (ACE) inhibitors have been shown to minimize fibrosis of the kidney tubulointerstitium in several diseases. In addition to lowering angiotensin II levels, ACE inhibitors can increase kinin levels and subsequently increase nitric oxide formation. To determine whether nitric oxide generation is a component of the beneficial effect of ACE inhibitors on renal fibrosis, enalapril, enalapril plus NG-nitro-L-arginine methyl ester (L-NAME) or L-arginine was administered to rats that had undergone unilateral ureteral obstruction (UUO). Ureteral obstruction caused significant increases in interstitial volume, monocyte macrophage infiltration, interstitial collagen IV and alpha-smooth muscle actin expression, transforming growth factor-beta 1 mRNA, collagen IV mRNA, and tissue inhibitor of metalloproteinase-1 mRNA. Enalapril treatment significantly blunted the increase in all parameters during UUO. Cotreatment of the animals with enalapril and L-NAME reversed the beneficial effect of enalapril in the obstructed kidney for all parameters. Treatment of animals with UUO with L-arginine significantly blunted the increase in all parameters except for transforming growth factor-beta 1 mRNA expression. In the enalapril- plus-L-NAME-treated animals, there were modest but significant increases in monocyte/macrophage infiltration of the interstitium and glomerulus, and collagen IV and alpha-smooth muscle actin expression in the interstitium of the contralateral unobstructed kidney. The urine nitrite concentration was significantly increased by either enalapril or L-arginine treatment, whereas L-NAME significantly reduced urine nitrite concentration. These results suggest that treatment modalities that increase nitric oxide formation have a beneficial effect on the progression of cellular and molecular parameters of tubulointerstitial fibrosis caused by obstruction of the ureter.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Arginine; Collagen; Enalapril; Enzyme Inhibitors; Female; Fibrosis; Kidney; Kidney Diseases; Kidney Tubules; Muscle, Smooth; NG-Nitroarginine Methyl Ester; Nitric Oxide; Rats; Rats, Sprague-Dawley; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) results in tubulointerstitial fibrosis of the obstructed kidney (OBK). In this study we report that a specific angiotensin II (Ang II) receptor antagonists, SC-51316, ameliorates the expansion of the renal cortical interstitium in the OBK of the rat at five days of UUO. This is similar to the effect of an angiotensin converting enzyme (ACE) inhibitor, enalapril. SC-51316 (20 mg/liter in the drinking water) or enalapril (200 mg/liter in the drinking water) was administered beginning 24 hours before UUO and continued through five days after UUO. The relative volume of the tubulointerstitium (Vv) was measured by a point-counting method, and monocyte/macrophage infiltration, alpha smooth muscle actin (alpha SMA), proliferating cell nuclear antigen (PCNA), and collagen type IV (collagen IV) protein deposition were examined histologically using specific antibodies. We also examined the mRNA levels of transforming growth factor beta 1 (TGF-beta 1) and collagen IV by reverse transcription polymerase chain reaction. In untreated rats with UUO, Vv was remarkably expanded; collagen IV and alpha SMA protein deposition in the interstitium and PCNA labeling of nuclei were increased. These changes were significantly ameliorated by administration of an ACE inhibitor or an Ang II receptor antagonist. A monocyte/macrophage infiltration was evident in the OBK of untreated or Ang II receptor antagonist treated rats but was greatly reduced in the OBK of rats given enalapril. Increased expression of TGF-beta 1 mRNA and collagen IV mRNA was blunted (40 to 75%) by the administration of Ang II receptor antagonist or enalapril. The Ang II receptor antagonist or the ACE inhibitor did not affect the contralateral kidney of rats with UUO or the control kidney of normal rats. This study indicates that the renin-angiotensin system has a major role in the pathogenesis of the tubulointerstitial fibrosis of obstructive nephropathy. The tubulointerstitial fibrosis of obstructive nephropathy is most likely mediated by an increased level of Ang II in renal tissue.

Topics: Actins; Angiotensin Receptor Antagonists; Animals; Blood Pressure; Collagen; Disease Models, Animal; Enalapril; Female; Immunohistochemistry; Monocytes; Nephritis, Interstitial; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Renin; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta; Triazoles; Ureteral Obstruction

Chronic unilateral ureteral obstruction (UUO) results in interstitial fibrosis of the affected kidney. In this study we determined that enalapril ameliorates the increased production of extracellular matrix (ECM) protein in the tubulointerstitium during UUO. The relative volume (Vv) of the tubulointerstitium measured by a point-counting method increased significantly at three or five days of UUO as compared to the contralateral kidney. Enalapril significantly blunted this increase at either three or five days. Immunofluorescence studies revealed that collagen type IV increased remarkably in both the tubular basement membrane (TBM) and the interstitial space at three or five days of UUO. Glomeruli did not show any change. Collagen types I and III were faintly stained in the control kidneys while they were obviously increased in the interstitial space of the obstructed kidney. We examined the expression of collagen type IV (COL IV) because this basement membrane matrix protein appeared to be a major ECM protein deposited in the tubulointerstitium of the obstructed kidney. Semiquantitative analysis of COL IV by immunofluorescence microscopy revealed that enalapril reduced slightly (21%) but significantly (P < 0.01) the deposition of COL IV in the obstructed kidney. Measurement of cyanogen bromide peptides from the obstructed kidney by Western blotting showed an increase of COL IV. This increase was reduced slightly (20%) by enalapril. The level of COL IV mRNA measured by reverse transcription-PCR was very low or undetectable in the control and contralateral kidneys, while it was significantly increased in the obstructed kidney at three or five days of UUO. COL IV mRNA was abundant in glomeruli while it was almost undetectable in renal tubules in the control and contralateral kidneys. However, COL IV mRNA was increased in renal tubules but not in the glomeruli of the obstructed kidney. Enalapril treatment resulted in a 42% decrease (P < 0.01) in COL IV mRNA in the cortex and a remarkable decrease in the renal tubules of the obstructed kidney at five days. Enalapril treatment resulted in an 89% decrease in the number of infiltrating ED-1 positive monocytes/macrophages. These results indicate that enalapril treatment ameliorates the tubulointerstitial fibrosis of the affected kidney in UUO. This effect of enalapril on fibrosis may be due to the severe reduction in monocytes/macrophages capable of secreting the profibrotic factor TGF-beta 1.

Topics: Animals; Base Sequence; Collagen; DNA Primers; Enalapril; Female; Fibrosis; Fluorescent Antibody Technique; Kidney Cortex; Kidney Tubules; Molecular Sequence Data; Rats; Rats, Sprague-Dawley; RNA, Messenger; Ureteral Obstruction

Renal interstitial fibrosis is a common consequence of chronic ureteral obstruction. While several cytokines may initiate fibrogenesis, TGF-beta is considered to be a major stimulating factor. It has been reported that TGF-beta 1 regulates extracellular matrix (ECM) synthesis, that thromboxane (Tx) stimulates ECM protein synthesis, and that angiotensin II (Ang II) increases expression of TGF-beta 1 mRNA in rat aortic smooth muscle cells. Therefore, we measured TGF-beta 1 mRNA expression by reverse transcription coupled with polymerase chain reaction in renal cortex of rats with unilateral ureteral obstruction (UUO) to determine whether Ang II and/or Tx stimulates increases in TGF-beta 1 mRNA. TGF-beta 1 mRNA levels in contralateral kidneys of rats with UUO did not change significantly during 14 days of obstruction, while in the obstructed kidney TGF-beta 1 mRNA levels were increased significantly after three days as compared to the control (unoperated rats) kidneys. The increase in TGF-beta 1 mRNA expression in the obstructed kidney cortex was found in tubular cells rather than glomeruli. OKY-046, an inhibitor of thromboxane synthase, did not affect the changes in TGF-beta 1 mRNA in the obstructed kidney. Enalapril, an angiotensin I converting enzyme inhibitor, significantly blunted but did not completely abrogate the increase in TGF-beta 1 mRNA. These data suggest that in obstruction TGF-beta 1 is increased at the transcriptional level and thus may play a role in initiating fibrogenesis in obstructive nephropathy. The effect of thromboxane on extracellular matrix synthesis does not appear to be mediated by TGF-beta 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Base Sequence; Enalapril; Female; Fibronectins; Kidney; Ligation; Methacrylates; Molecular Probes; Molecular Sequence Data; Polymerase Chain Reaction; Rats; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction

Bleeding time is prolonged following resection of kidney tissue as well as after ureteral occlusion. Bilateral nephrectomy raises bleeding time from 17 to 67 min, and blood loss can be increased from 2 to 12 microliters/min. Plasmatic coagulation factors remain unchanged in uremic rats. There is no influence of various surgical interventions producing uremia on function of thrombocytes. In rats with intact kidney function and following bilateral nephrectomy a diminution of bleeding time is demonstrable after administration of histamine or captopril. Shortening of bleeding time by the antifibrinolytic substance p-aminomethylbenzoic acid seems to indicate an increased fibrinolytic activity in uremic rats.

Topics: 4-Aminobenzoic Acid; Angiotensin II; Animals; Bleeding Time; Blood Coagulation; Captopril; Chlorisondamine; Enalapril; Female; Fibronectins; Histamine; Nephrectomy; para-Aminobenzoates; Platelet Aggregation; Rats; Rats, Inbred Strains; Uremia; Ureteral Obstruction; Vasopressins

After unilateral release of bilateral ureteral obstruction (BUO), there is a significant increase in renal vasoconstriction that accounts for the marked decrease in glomerular filtration rate and effective renal plasma flow seen in this setting. We examined the potential role of antidiuretic hormone (ADH), a vasoconstrictor of the renal circulation, on renal hemodynamics in female Sprague-Dawley rats with BUO of 24-hr duration. Rats with BUO had significantly higher plasma values of ADH 65.1 +/- 12.2 vs. 12.1 +/- 4.1 pg/ml), sodium (145.4 +/- 0.91 vs 138.6 +/- 1.06 mEq/liter), and osmolality (375.6 +/- 2.0 vs 310.1 +/- 3.6 mOsm/kg) than sham-operated rats. Rats with BUO pretreated with enalapril, an angiotensin-converting enzyme inhibitor, before obstruction had somewhat higher, but not significantly different, plasma values for ADH (84.6 +/- 20.8 pg/ml) than rats with BUO not given enalapril. Rats with unilateral ureteral obstruction of 24-hr duration had plasma levels of ADH (8.2 +/- 1.3) not different from those in sham-operated rats. Rats with BUO pretreated with a specific antagonist of the V1-type receptor for ADH had significantly greater values for the glomerular filtration rate (2.31 +/- 0.24 vs 1.44 +/- 0.08 ml/min/kg body wt) and the effective renal plasma flow (8.95 +/- 0.71 vs 3.81 +/- 0.44 ml/min/kg body wt) and significantly lower values for mean arterial pressure (140.3 +/- 2.0 vs 159.1 +/- 5.5 mm Hg) than did BUO rats not given the antagonist. The results indicate that high levels of ADH play an important role in the decrease in the glomerular filtration rate and effective renal plasma flow observed in rats with BUO of 24 hr. The significant increase in ADH levels after BUO of 24-hr duration may be due to an increase in osmotic stimulation as a consequence of hypernatremia. Activation of the renin-angiotensin axis, known to occur after BUO or unilateral ureteral obstruction of 24-hr duration, does not appear to have a role in the increased circulating levels of ADH.

Topics: Animals; Blood Pressure; Enalapril; Female; Glomerular Filtration Rate; Hematocrit; Kidney Function Tests; Potassium; Rats; Rats, Inbred Strains; Reference Values; Sodium; Ureteral Obstruction; Urine; Vasopressins

The present studies were designed to analyze the potential contribution of angiotensin II and thromboxane A2 to the remarkable decrease in glomerular filtration rate (GFR) and renal plasma flow observed after unilateral release of 24-hour bilateral ureteral obstruction. Pretreatment of the animals with inhibitors of either thromboxane or angiotensin synthesis for 48 hours prior to and during obstruction eliminated the contribution of these vasoconstrictors. Inhibition of these vasoconstrictors during the period of obstruction results in a greater increase in renal plasma flow and GFR than when inhibition was accomplished after release of the obstruction. These data suggest a greater role for these vasoconstrictors in the decrease in GFR that occurs with obstruction. Simultaneous inhibition of thromboxane and angiotensin production normalized GFR of the postobstructed kidney. Administration of atrial peptide after release of obstruction in the different groups of rats resulted in further increases in GFR, urine flow and absolute sodium excretion. It is suggested that atrial peptide participates in the renal hemodynamic changes that occur in the postobstructed kidney.

Topics: Acrylates; Animals; Atrial Natriuretic Factor; Enalapril; Female; Glomerular Filtration Rate; Kidney; Methacrylates; Rats; Rats, Inbred Strains; Reference Values; Thromboxane-A Synthase; Ureteral Obstruction; Vasoconstrictor Agents

Chronic partial ureteral obstruction (CPUO) causes an increase in renal vascular resistance (RVR) that can be prevented by angiotensin II (ANG II)-converting enzyme inhibition. To assess the early effects of CPUO, guinea pigs subjected to neonatal left ureteral obstruction were anesthetized at 11-13 days of age for measurement of cardiac output and renal blood flow (RBF) using radioactive microspheres. Although RBF of the hydronephrotic kidney was not decreased at this age, that of the intact kidney more than doubled (P less than 0.01). To evaluate the hemodynamic response to relief of 5 or 10 days of neonatal left CPUO, animals were studied at 19-28 days of age. Although chronic enalapril maleate administration (30 mg.kg-1.day-1) did not further reduce the ratio of RVR to total vascular resistance (TVR) of the postobstructed kidney, it lowered RVR/TVR of the intact contralateral kidney by 40% (P less than 0.05). Renal renin content [RRC, pg angiotensin I (ANG I).mg protein-1.h-1] was twofold higher in both kidneys of animals with unilateral CPUO compared with those of sham-operated guinea pigs (P less than 0.03), and relief of obstruction normalized RRC. The rise in RVR/TVR resulting from ANG II infusion was not different in left kidneys of sham, CPUO, and CPUO-relief groups. However, for the intact kidney of animals with contralateral relief of CPUO, the increase was greater than in remaining groups (P less than 0.05). We conclude that by reducing intrarenal renin, relief of neonatal unilateral CPUO decreased ANG-mediated vasoconstriction of the postobstructed kidney and increased the vasoconstrictor response of the intact kidney to ANG II.

Topics: Aging; Animals; Animals, Newborn; Blood Pressure; Cardiac Output; Enalapril; Female; Guinea Pigs; Kidney; Male; Reference Values; Renal Circulation; Renin-Angiotensin System; Ureteral Obstruction; Vascular Resistance

To investigate the morphologic correlates of decreased renal blood flow and growth arrest resulting from chronic partial ureteral obstruction in the neonate, guinea pigs were subjected to unilateral ureteral constriction within the first 2 days of life and were studied at 3 and 8 wk of age. Severity of histologic changes in the obstructed and intact contralateral kidney was assessed by light microscopy. Morphometric glomerular measurements were made using a computerized tracing device. Since contralateral nephrectomy or administration of angiotensin converting enzyme inhibitor (enalapril) result in increased blood flow to the obstructed kidney, morphologic changes were also examined in separate groups of animals subjected to these maneuvers, and were compared to appropriate controls. Ipsilateral chronic partial ureteral obstruction resulted in decreased glomerular volume (p less than 0.0001) and increased glomerular crowding associated with tubular dilatation and progressive glomerular sclerosis, tubular atrophy, and interstitial fibrosis. The intact contralateral kidney underwent hypertrophy with increase in glomerular volume (p less than 0.0001) and decreased glomerular density. Contralateral nephrectomy prevented the decrease in glomerular volume in the obstructed kidney and resulted in decreased glomerular density and reduced tubular atrophy at 3 wk of age. Enalapril prevented the decrease in glomerular volume at 3 wk of age, but glomerular and tubular changes progressed and were unaffected by enalapril at 8 wk. Left kidney glomerular volume was directly related to renal blood flow (r = 0.71, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Constriction; Enalapril; Female; Guinea Pigs; Kidney; Kidney Glomerulus; Kidney Tubules; Male; Nephrectomy; Organ Size; Renal Circulation; Ureteral Obstruction

To evaluate the relative contribution of endogenous vasoactive compounds to maintenance of increased renal vascular resistance in neonatal obstructive nephropathy, cardiac output and renal blood flow were measured using radioactive microspheres in 25 +/- 3 day-old guinea pigs subjected to unilateral partial ureteral constriction within the first two days of life. Mass and renal blood flow of the obstructed kidney were significantly lower than those of the contralateral kidney. Following a control period, thromboxane synthesis was blocked by infusion of OKY-046, after which prostaglandin synthesis was inhibited by indomethacin. In a separate group of animals, angiotensin converting enzyme inhibitor, MK-422, was infused before or after administration of OKY-046. While neither OKY-046 nor indomethacin had a consistent effect on vascular resistance, infusion of MK-422 resulted in selective reduction of renal vascular resistance of the obstructed kidney compared to resistance in the intact kidney and other vascular beds. Removal of the contralateral kidney at the time of ureteral constriction in an additional group of animals resulted in hypertrophy and vasodilation of the obstructed kidney which was not altered by thromboxane or cyclooxygenase inhibition. We conclude that in the neonatal kidney subjected to ipsilateral chronic partial ureteral obstruction, vasoconstriction is mediated at least in part by angiotensin II, but not by thromboxane. Furthermore, vasodilation of the obstructed kidney resulting from contralateral nephrectomy is not dependent on prostaglandin synthesis. Renal vascular resistance of the kidney with prolonged partial ureteral constriction in early development thus appears to be inversely related to renal growth and is not significantly mediated by endogenous prostanoids.

Topics: Angiotensin II; Animals; Animals, Newborn; Cardiac Output; Enalapril; Enalaprilat; Female; Guinea Pigs; Indomethacin; Kidney; Male; Methacrylates; Microspheres; Prostaglandins; Renal Circulation; Strontium Radioisotopes; Thromboxanes; Time Factors; Ureteral Obstruction; Vascular Resistance

To evaluate the role of angiotensin II (ANG II) in renal vasoconstriction due to ipsilateral CPUO, guinea pigs were subjected to incomplete left ureteral stenosis within the first 48 hr of life, and were given enalapril from the 14th day of life until study at 23 +/- 3 days or 8 weeks of age. Renal blood flow (RBF) was measured using radioactive microspheres, and glomerular filtration rate (GFR) was derived from inulin extraction. The number of perfused glomeruli per kidney was determined following in vivo India ink perfusion. Enalapril treatment resulted in an 83% rise in RBF of the obstructed kidney, from 2.58 +/- 0.26 to 4.73 +/- 0.48 ml/min (P less than 0.001), which was associated with a 26% increase in number of perfused glomeruli (P less than 0.01). Mean GFR of the hydronephrotic kidney increased from 0.13 +/- 0.02 to 0.37 +/- 0.10 ml/min (P less than 0.05). Enalapril had no effect on intraureteral pressure of the obstructed left kidney after 7 to 13 days of administration, and did not affect renal mass or ureteral diameter after 6 weeks of treatment. It is concluded that hemodynamic consequences of CPUO in the neonate may be attenuated by ANG converting enzyme inhibition. The primary effect of enalapril is most likely inhibition of intrarenal ANG II formation.

Topics: Angiotensin II; Animals; Animals, Newborn; Disease Models, Animal; Enalapril; Glomerular Filtration Rate; Guinea Pigs; Hemodynamics; Hydronephrosis; Kidney Glomerulus; Time Factors; Ureteral Obstruction; Vascular Resistance