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Nørregaard R, Mutsaers HAM, Frøkiær J, Kwon TH. Obstructive nephropathy and molecular pathophysiology of renal interstitial fibrosis. Physiol Rev 2023; 103:2827-2872. [PMID: 37440209 PMCID: PMC10642920 DOI: 10.1152/physrev.00027.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 07/05/2023] [Accepted: 07/09/2023] [Indexed: 07/14/2023] Open
Abstract
The kidneys play a key role in maintaining total body homeostasis. The complexity of this task is reflected in the unique architecture of the organ. Ureteral obstruction greatly affects renal physiology by altering hemodynamics, changing glomerular filtration and renal metabolism, and inducing architectural malformations of the kidney parenchyma, most importantly renal fibrosis. Persisting pathological changes lead to chronic kidney disease, which currently affects ∼10% of the global population and is one of the major causes of death worldwide. Studies on the consequences of ureteral obstruction date back to the 1800s. Even today, experimental unilateral ureteral obstruction (UUO) remains the standard model for tubulointerstitial fibrosis. However, the model has certain limitations when it comes to studying tubular injury and repair, as well as a limited potential for human translation. Nevertheless, ureteral obstruction has provided the scientific community with a wealth of knowledge on renal (patho)physiology. With the introduction of advanced omics techniques, the classical UUO model has remained relevant to this day and has been instrumental in understanding renal fibrosis at the molecular, genomic, and cellular levels. This review details key concepts and recent advances in the understanding of obstructive nephropathy, highlighting the pathophysiological hallmarks responsible for the functional and architectural changes induced by ureteral obstruction, with a special emphasis on renal fibrosis.
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Affiliation(s)
- Rikke Nørregaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Jørgen Frøkiær
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Tae-Hwan Kwon
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea
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Sung CC, Poll BG, Lin SH, Murillo-de-Ozores AR, Chou CL, Chen L, Yang CR, Chen MH, Hsu YJ, Knepper MA. Early Molecular Events Mediating Loss of Aquaporin-2 during Ureteral Obstruction in Rats. J Am Soc Nephrol 2022; 33:2040-2058. [PMID: 35918145 PMCID: PMC9678028 DOI: 10.1681/asn.2022050601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/19/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Ureteral obstruction is marked by disappearance of the vasopressin-dependent water channel aquaporin-2 (AQP2) in the renal collecting duct and polyuria upon reversal. Most studies of unilateral ureteral obstruction (UUO) models have examined late time points, obscuring the early signals that trigger loss of AQP2. METHODS We performed RNA-Seq on microdissected rat cortical collecting ducts (CCDs) to identify early signaling pathways after establishment of UUO. RESULTS Vasopressin V2 receptor (AVPR2) mRNA was decreased 3 hours after UUO, identifying one cause of AQP2 loss. Collecting duct principal cell differentiation markers were lost, including many not regulated by vasopressin. Immediate early genes in CCDs were widely induced 3 hours after UUO, including Myc, Atf3, and Fos (confirmed at the protein level). Simultaneously, expression of NF-κB signaling response genes known to repress Aqp2 increased. RNA-Seq for CCDs at an even earlier time point (30 minutes) showed widespread mRNA loss, indicating a "stunned" profile. Immunocytochemical labeling of markers of mRNA-degrading P-bodies DDX6 and 4E-T indicated an increase in P-body formation within 30 minutes. CONCLUSIONS Immediately after establishment of UUO, collecting ducts manifest a stunned state with broad disappearance of mRNAs. Within 3 hours, there is upregulation of immediate early and inflammatory genes and disappearance of the V2 vasopressin receptor, resulting in loss of AQP2 (confirmed by lipopolysaccharide administration). The inflammatory response seen rapidly after UUO establishment may be relevant to both UUO-induced polyuria and long-term development of fibrosis in UUO kidneys.
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Affiliation(s)
- Chih-Chien Sung
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Brian G. Poll
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Adrian R. Murillo-de-Ozores
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Chung-Lin Chou
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Chin-Rang Yang
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Min-Hsiu Chen
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Juei Hsu
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Mark A. Knepper
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
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Hu S, Xie H, Luo R, Feng P, Liu Q, Han M, Kong Y, Zou X, Wang W, Li C. Inhibition of IL-1β by Aliskiren Improved Renal AQP2 Expression and Urinary Concentration Defect in Ureteral Obstruction and Release. Front Physiol 2019; 10:1157. [PMID: 31572210 PMCID: PMC6753185 DOI: 10.3389/fphys.2019.01157] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 08/28/2019] [Indexed: 12/19/2022] Open
Abstract
We previously demonstrated that ureteral obstruction is associated with a urinary concentrating defect and reduced expression of renal aquaporins (AQPs), in which the renin–angiotensin system (RAS) may play an important role. The aims of the present study were to examine whether the renin inhibitor aliskiren could prevent the reduction in AQP expression and improve the urinary concentrating capacity in mice with bilateral ureteral obstruction (BUO) and BUO release. BUO was performed for 24 h, and BUO release was performed for 1 (B-R1D) or 3 days (B-R3D) with or without aliskiren treatment. Aliskiren prevented polyuria and decreased urine osmolality induced by B-R3D. In mice with BUO and BUO release, aliskiren attenuated the reduction in AQP2 protein and mRNA expression in the obstructed kidneys. B-R3D increased the protein expression of NLRP3 inflammasome components ASC, caspase-1, and interleukin-1β in the obstructed kidneys, which was markedly prevented by aliskiren. Moreover, the NF-κB inhibitor Bay 11-7082 blocked NLRP3 inflammasome activation and attenuated the decrease in AQP2 protein expression in primary cultured rat inner medullary collecting duct cells treated with angiotensin II. These results indicate that the renin inhibitor aliskiren increases water channel AQP2 expression at least partially by suppressing NLRP3 inflammasome activation in the obstructed kidneys of mice with BUO and BUO release.
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Affiliation(s)
- Shan Hu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Haixia Xie
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Renfei Luo
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Pinning Feng
- Department of Clinical Laboratory, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qiaojuan Liu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Mengke Han
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yonglun Kong
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xuenong Zou
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Weidong Wang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Department of Nephrology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Chunling Li
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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Sun Y, Zhang Y, Zhu Y, Zhang A, Huang S, Yin X, Ding G, Liu M, Jia Z. Inhibition of mitochondrial complex-1 restores the downregulation of aquaporins in obstructive nephropathy. Am J Physiol Renal Physiol 2016; 311:F777-F786. [PMID: 27413198 DOI: 10.1152/ajprenal.00215.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/05/2016] [Indexed: 01/12/2023] Open
Abstract
Obstructive kidney disease is a common complication in the clinic. Downregulation of aquaporins (AQPs) in obstructed kidneys has been thought as a key factor leading to the polyuria and impairment of urine-concentrating capability after the release of kidney obstruction. The present study was to investigate the role of mitochondrial complex-1 in modulating AQPs in obstructive nephropathy. Following 7-day unilateral ureteral obstruction (UUO), AQP1, AQP2, AQP3, and vasopressin 2 (V2) receptor were remarkably reduced as determined by qRT-PCR and/or Western blotting. Notably, inhibition of mitochondrial complex-1 by rotenone markedly reversed the downregulation of AQP1, AQP2, AQP3, and V2 In contrast, AQP4 was not affected by kidney obstruction or rotenone treatment. In a separate study, rotenone also attenuated AQPs' downregulation after 48-h UUO. To study the potential mechanisms in mediating the rotenone effects on AQPs, we examined the regulation of the COX-2/microsomal prostaglandin E synthase (mPGES)-1/PGE2/EP pathway and found that COX-2, mPGES-1, and renal PGE2 content were all significantly elevated in obstructive kidneys, which was not affected by rotenone treatment. For EP receptors, EP2 and EP4 but not EP1 and EP3 were upregulated in obstructive kidneys. Importantly, rotenone strikingly suppressed EP1 and EP4 but not EP2 and EP3 receptors. However, treatment of EP1 antagonist SC-51322 could not affect AQPs' reduction in obstructed kidneys. Collectively, these findings suggested an important role of mitochondrial dysfunction in modulating AQPs and V2 receptor in obstructive nephropathy possibly via prostaglandin-independent mechanisms.
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Affiliation(s)
- Ying Sun
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Department of Pharmacy, Xuzhou Medical University, Xuzhou, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Yue Zhang
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Yangyang Zhu
- Department of Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Aihua Zhang
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Songming Huang
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Xiaoxin Yin
- Department of Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Guixia Ding
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Mi Liu
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China; Nanjing Key Laboratory of Pediatric, Nanjing Children Hospital, Affiliated to Nanjing Medical University, Nanjing, China; and Institute of Pediatrics, Nanjing Medical University, Nanjing, China
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Wang W, Luo R, Lin Y, Wang F, Zheng P, Levi M, Yang T, Li C. Aliskiren restores renal AQP2 expression during unilateral ureteral obstruction by inhibiting the inflammasome. Am J Physiol Renal Physiol 2015; 308:F910-22. [PMID: 25694485 DOI: 10.1152/ajprenal.00649.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 02/11/2015] [Indexed: 12/17/2022] Open
Abstract
Ureteral obstruction is associated with reduced expression of renal aquaporins (AQPs), urinary concentrating defects, and an enhanced inflammatory response, in which the renin-angiotensin system (RAS) may play an important role. We evaluated whether RAS blockade by a direct renin inhibitor, aliskiren, would prevent the decreased renal protein expression of AQPs in a unilateral ureteral obstruction (UUO) model and what potential mechanisms may be involved. UUO was performed for 3 days (3UUO) and 7 days (7UUO) in C57BL/6 mice with or without aliskiren injection. In 3UUO and 7UUO mice, aliskiren abolished the reduction of AQP2 protein expression but not AQP1, AQP3, and AQP4. mRNA levels of renal AQP2 and vasopressin type 2 receptor were decreased in obstructed kidneys of 7UUO mice, which were prevented by aliskiren treatment. Aliskiren treatment was also associated with a reduced inflammatory response in obstructed kidneys of UUO mice. Aliskiren significantly decreased mRNA levels of several proinflammatory factors, such as transforming growth factor-β and tumor necrosis factor-α, seen in obstructed kidneys of UUO mice. Interestingly, mRNA and protein levels of the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome components apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, and IL-1β were dramatically increased in obstructed kidneys of 7UUO mice, which were significantly suppressed by aliskiren. In primary cultured inner medullary collecting duct cells, IL-1β significantly decreased AQP2 expression. In conclusions, RAS blockade with the direct renin inhibitor aliskiren increased water channel AQP2 expression in obstructed kidneys of UUO mice, at least partially by preventing NLRP3 inflammasome activation in association with ureteral obstruction.
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Affiliation(s)
- Weidong Wang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Renfei Luo
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yu Lin
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Feifei Wang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Peili Zheng
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Moshe Levi
- Division of Renal Diseases and Hypertension, Anschutz Medical Campus, University of Colorado, Aurora, Colorado; and
| | - Tianxin Yang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China; Department of Medicine, University of Utah, and Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Chunling Li
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China;
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López-Novoa JM, Martínez-Salgado C, Rodríguez-Peña AB, Hernández FJL. Common pathophysiological mechanisms of chronic kidney disease: Therapeutic perspectives. Pharmacol Ther 2010; 128:61-81. [DOI: 10.1016/j.pharmthera.2010.05.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 05/25/2010] [Indexed: 12/17/2022]
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Jensen AM, Nørregaard R, Topcu SO, Frøkiaer J, Pedersen M. Oxygen tension correlates with regional blood flow in obstructed rat kidney. ACTA ACUST UNITED AC 2009; 212:3156-63. [PMID: 19749109 DOI: 10.1242/jeb.029249] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
As renal tissue oxygen tension (P(O(2))) is determined by the balance between oxygen supply and consumption, direct tissue P(O(2)) measurements are essential when evaluating the presence of hypoxia. The present study aimed at evaluating invasively and continuously the renal medullary and cortical tissue P(O(2)) by novel fibre-optic probes in rats subjected to acute unilateral ureteral obstruction (AUUO). In parallel, regional blood flow measurements were obtained by MRI to investigate the relationship between regional blood flow and tissue oxygen tension. The abundance of transport proteins was determined by immunoblotting. In the obstructed kidney, AUUO caused a prompt decrease in medullary tissue P(O(2)) to 60% of baseline level whereas cortical tissue P(O(2)) was unchanged. By contrast, tissue P(O(2)) slightly increased in the non-obstructed kidney. These changes developed during the first 30 min after AUUO and persisted for the 3 h observation period. Medullary blood flow declined 1.5-2 h after induction of AUUO to 61% of baseline level in the obstructed kidney. By contrast, cortical blood flow increased to 108% of baseline level in the non-obstructed kidney. Finally, the abundance of phosphorylated aquaporin 2 decreased significantly in the obstructed kidney medulla, but increased in the obstructed kidney cortex. The Na(+)/K(+)-ATPase abundance increased in the obstructed kidney medulla whereas the Na(+)/K(+)/2Cl(-) co-transporter abundance remained unchanged in the obstructed kidney. In conclusion, measurements of regional blood flow reflect tissue P(O(2)) changes during AUUO suggesting that reduced regional blood flow is a predictor of local hypoxia. Furthermore, the abundance of major transport protein is independent of tissue P(O(2)).
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Affiliation(s)
- Anja M Jensen
- The Water and Salt Research Center, Aarhus University Hospital, Skejby, DK 8200, Aarhus N, Denmark.
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Jensen AM, Li C, Praetorius HA, Nørregaard R, Frische S, Knepper MA, Nielsen S, Frøkiaer J. Angiotensin II mediates downregulation of aquaporin water channels and key renal sodium transporters in response to urinary tract obstruction. Am J Physiol Renal Physiol 2006; 291:F1021-32. [PMID: 16757730 DOI: 10.1152/ajprenal.00387.2005] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renin-angiotensin system is well known to be involved in the pathophysiological changes in renal function after obstruction of the ureter. Previously, we demonstrated that bilateral ureteral obstruction (BUO) is associated with dramatic changes in the expression of both renal sodium transporters and aquaporin water channels (AQPs). We now examined the effects of the AT1-receptor antagonist candesartan on the dysregulation of AQPs and key renal sodium transporters in rats subjected to 24-h BUO and followed 2 days after release of BUO (BUO-2R). Consistent with previous observations, BUO-2R resulted in a significantly decreased expression of AQP1, -2, and -3 compared with control rats. Concomitantly, the rats developed polyuria and reduced urine osmolality. Moreover, expression of the type 2 Na-phosphate cotransporter (NaPi-2) and type 1 bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) was markedly reduced, consistent with postobstructive natriuresis. Candesartan treatment from the onset of obstruction attenuated the reduction in GFR (3.1 ± 0.4 vs. 1.7 ± 0.3 ml·min−1·kg−1) and partially prevented the reduction in the expression of AQP2 (66 ± 21 vs. 13 ± 2%, n = 7; P < 0.05), NaPi-2 (84 ± 6 vs. 57 ± 10%, n = 7; P < 0.05), and NKCC2 (89 ± 12 vs. 46% ± 11, n = 7; P < 0.05). Consistent with this, candesartan treatment attenuated the increase in urine output (58 ± 4 vs. 97 ± 5 μl·min−1·kg−1, n = 7; P < 0.01) and the reduction in sodium reabsorption (433 ± 62 vs. 233 ± 45 μmol·min−1·kg−1, n = 7; P < 0.05) normally found in rats subjected to BUO. Moreover, candesartan treatment attenuated induction of cyclooxygenase 2 (COX-2) expression in the inner medulla, suggesting that COX-2 induction in response to obstruction is regulated by ANG II. In conclusion, candesartan prevents dysregulation of AQP2, sodium transporters, and development of polyuria seen in BUO. This strongly supports the view that candesartan protects kidney function in response to urinary tract obstruction.
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Affiliation(s)
- Anja M Jensen
- The Water and Salt Research Center, Univ. of Aarhus, Institute of Clinical Medicine/Dept. of Clinical Physiology, Aarhus Univ. Hospital, Brendstrupgaardsvej, DK-8200 Aarhus N., Denmark
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Eiam-Ong S, Udom J, Sueblinvong T, Eiam-Ong S. Apoptosis of circulating lymphocyte in rats with unilateral ureteral obstruction: Role of angiotensin II. Nephrology (Carlton) 2005; 10:464-9. [PMID: 16221096 DOI: 10.1111/j.1440-1797.2005.00440.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND 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. METHODS 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. RESULTS 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. CONCLUSION 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.
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Affiliation(s)
- Somchit Eiam-Ong
- Department of Physiology, Faculty of Medicine, Chulalongkorn University Hospital, Bangkok, Thailand
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Contribution of the renin-angiotensin system to the intrarenal resistive index in chronic unilateral partial ureteral obstruction in dogs. J Med Ultrason (2001) 2005; 32:101-5. [PMID: 27277265 DOI: 10.1007/s10396-005-0044-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 03/24/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE We investigated the role of the renin-angiotensin system on intrarenal hemodynamics in chronic unilateral partial ureteral obstruction (UPUO) using Doppler ultrasound (US). METHODS In 11 dogs with chronic UPUO, we determined the renal resistive index (RI) before and 1 h after the intravenous infusion of an angiotensin-converting enzyme (ACE) inhibitor (captopril), an angiotensin II receptor type 1 (ART1) antagonist (L-158,809), and the combination of these two drugs. Change in resistive index (ΔRI) was calculated as RI after the administration of each tested material minus baseline RI. RESULTS At the baseline measurement, significant differences in RI were seen between obstructed and nonobstructed kidneys. ACE inhibitor, ART1 antagonist, or the combination of these drugs did not result in any significant changes in RI in either obstructed or nonobstructed kidneys. However, in obstructed kidneys, ΔRI in the combination of ACE inhibitor and ART1 antagonist were significantly greater than those in ACE inhibitor or ART1 antagonist alone, whereas there were no significant differences in those values in nonobstructed kidneys. CONCLUSION These observations suggest that the renin-angiotensin system in dogs with chronic UPUO may not contribute significantly to the differences in intrarenal RI between obstructed and nonobstructed kidneys. However, the angiotensin-producing pathways and angiotensin II receptor subtypes other than ACE and ART1 may have some different effects between obstructed and nonobstructed kidneys.
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Tillig B, Constantinou CE. Supraspinal N-methyl-D-aspartate receptor inhibition influences the micturition reflex and function of the upper urinary tract of anesthetized and conscious rats. Neurourol Urodyn 2003; 22:164-75. [PMID: 12579635 DOI: 10.1002/nau.10080] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIMS To examine the effects of N-methyl-D-aspartate (NMDA) receptor antagonists on the frequency/volume (F/V) characteristics of micturition of conscious and anesthetized rats in relation to the mechanisms of renal urine output and pyelo-ureteral transport function of the upper urinary tract. METHODS Micturition F/V characteristics of 24 conscious female Sprague-Dawley rats, each weighting 160-180 g, were evaluated in a metabolic chamber. Control values of (F/V) were first obtained after administration of a 5-mL loading dose of saline solution and compared with intraperitoneal (i.p.) injection of 0.3-6.0 mg/kg of LY274614 (LY) and 0.3-40 mg/kg of dextromethorphan (DEX). Upper urinary tract studies were performed on two groups of urethane anesthetized rats (1.2 g/kg, s.c.). A group of 17 rats was used for intravenous (i.v.) injection of 1-30 mg/kg of LY and 1-10 mg/kg of DEX. In a second group of 12 rats, 0.2 mg/kg of LY and DEX were administered intracerebroventricularly (i.c.v.), by placing a catheter into the third ventricle. In anesthetized rats, continuous cystometrograms (CMG) were done while perfusing the renal pelvis with indigo carmine, and measuring pelvic and arterial pressure and as well as visualizing the transport of urine within the upper urinary tract by using videomicroscopic imaging. RESULTS In conscious rats, the i.p. injection of LY and DEX produced a significant and dose-dependent increase in functional bladder capacity and a considerable increase in diuresis. In anesthetized rats, i.v. and i.c.v. administration of LY and DEX affected the micturition reflex, reflected as a significant increase in bladder capacity and preleakage pressure. Videomicroscopic imaging shows dilation of the ureter and a dilution of the dyed urine after the i.v. and i.c.v. injection of LY and DEX. The frequency of ureteral peristalsis and renal pelvic contractions were significantly decreased after i.v. and i.c.v. injection of LY as well as DEX. CONCLUSIONS The present study shows that the NMDA receptor antagonists LY and DEX given systemically (i.v. and i.p.) or intracerebroventricularly influence the micturition reflex and modulate pyelo-ureteral motility as well as the rate of urine production. From the present study, it is suggested that NMDA receptors are directly involved in regulating pyelo-ureteral peristalsis as well as in the coordination of urine transport between upper and lower urinary tract.
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Affiliation(s)
- Bernd Tillig
- Department of Pediatric Surgery, Ruhr-University of Bochum, Germany.
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12
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Dalmose AL, Hvistendahl JJ, Olsen LH, Eskild-Jensen A, Djurhuus JC, Swindle MM. Surgically induced urologic models in swine. J INVEST SURG 2000; 13:133-45. [PMID: 10933109 DOI: 10.1080/08941930050075829] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The porcine urological system is similar anatomically and physiologically to that of humans. Swine have a true multirenculate, multipapillate kidney with a calyceal system like that of humans. The gross anatomic and histologic characteristics of the porcine and the human kidney are more similar than most other commonly used laboratory animals. The physiologic functions of the urinary system including urodynamic parameters are also similar to humans. Swine have been used extensively as models of urologic conditions in humans, most commonly in obstructive urologic syndromes. A large number of investigative procedures can be performed in one experiment both in acute and chronic models. Recently, a new technique of surgically induced antenatal lower urinary tract obstruction in swine has been developed.
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Affiliation(s)
- A L Dalmose
- Institute of Experimental Clinical Research, Aarhus University Hospital, Denmark
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Evans JP, Rogers GG. The absence of a triphasic renovascular response by the multicalyceal kidney of the primate in reaction to acute, complete, unilateral, ureteric obstruction. J Med Primatol 1998; 27:223-33. [PMID: 9926977 DOI: 10.1111/j.1600-0684.1998.tb00241.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The early renovascular response by the ipsilateral kidney to acute, total, unilateral, ureteric obstruction was investigated in the adult male chacma baboon (Papio ursinus). Complete occlusion was effected by ligating the ureter at the brim of the bony pelvis ("N"=10). Sham studies were enacted using the same method but the ureter was not obstructed ("N"=11). Haemodynamic reactions were monitored for 12 hours. Compared with the sham-occluded set, the renal pelvic pressures in the obstructed group were significantly increased (P<0.05) from the second hour of the inquiry. However, there were no significant differences in renal blood flow, either between or within the respective cohorts. In this study, the renovascular response to acute ureteric occlusion was similar to that displayed by the multicalyceal kidney of other species under identical conditions. This reaction was fundamentally different to that exhibited by the unicalyceal kidney under similar circumstances.
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Affiliation(s)
- J P Evans
- Department of Urology, University of The Witwatersrand Faculty of Health Sciences, Johannesburg, Republic of South Africa
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Abstract
Recent study has increased the understanding of the physiological processes occurring in obstructive uropathy, in particular the role played by vasoactive mediators and cellular mechanisms. There is an emphasis on developing effective and less invasive means of detection and treatment of ureteric obstruction, although it remains to be determined how the techniques currently being assessed will impact on clinical practice.
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Affiliation(s)
- L S Young
- Department of Surgery, Mater Misericordiae Hospital, Dublin, Ireland
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Eicosanoid Excretion from the Contralateral Kidney in Pigs with Complete Unilateral Ureteral Obstruction. J Urol 1995. [DOI: 10.1016/s0022-5347(01)67032-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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