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The effect of albumin administration on renal dysfunction after experimental surgical obstructive jaundice in male rats. JOURNAL OF TAIBAH UNIVERSITY FOR SCIENCE 2018. [DOI: 10.1016/j.jtusci.2015.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Packer M. Role of the sodium-hydrogen exchanger in mediating the renal effects of drugs commonly used in the treatment of type 2 diabetes. Diabetes Obes Metab 2018; 20:800-811. [PMID: 29227582 DOI: 10.1111/dom.13191] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 12/07/2017] [Indexed: 01/19/2023]
Abstract
Diabetes is characterized by increased activity of the sodium-hydrogen exchanger (NHE) in the glomerulus and renal tubules, which contributes importantly to the development of nephropathy. Despite the established role played by the exchanger in experimental studies, it has not been specifically targeted by those seeking to develop novel pharmacological treatments for diabetes. This review demonstrates that many existing drugs that are commonly prescribed to patients with diabetes act on the NHE1 and NHE3 isoforms in the kidney. This action may explain their effects on sodium excretion, albuminuria and the progressive decline of glomerular function in clinical trials; these responses cannot be readily explained by the influence of these drugs on blood glucose. Agents that may affect the kidney in diabetes by virtue of an action on NHE include: (1) insulin and insulin sensitizers; (2) incretin-based agents; (3) sodium-glucose cotransporter 2 inhibitors; (4) antagonists of the renin-angiotensin system (angiotensin converting-enzyme inhibitors, angiotensin receptor blockers and angiotensin receptor neprilysin inhibitors); and (5) inhibitors of aldosterone action and cholesterol synthesis (spironolactone, amiloride and statins). The renal effects of each of these drug classes in patients with type 2 diabetes may be related to a single shared biological mechanism.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas
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Mordasini D, Loffing-Cueni D, Loffing J, Beatrice R, Maillard MP, Hummler E, Burnier M, Escher G, Vogt B. ENaC activity in collecting ducts modulates NCC in cirrhotic mice. Pflugers Arch 2015; 467:2529-39. [PMID: 26055235 DOI: 10.1007/s00424-015-1711-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/24/2015] [Accepted: 05/18/2015] [Indexed: 01/07/2023]
Abstract
Cirrhosis is a frequent and severe disease, complicated by renal sodium retention leading to ascites and oedema. A better understanding of the complex mechanisms responsible for renal sodium handling could improve clinical management of sodium retention. Our aim was to determine the importance of the amiloride-sensitive epithelial sodium channel (ENaC) in collecting ducts in compensate and decompensate cirrhosis. Bile duct ligation was performed in control mice (CTL) and collecting duct-specific αENaC knockout (KO) mice, and ascites development, aldosterone plasma concentration, urinary sodium/potassium ratio and sodium transporter expression were compared. Disruption of ENaC in collecting ducts (CDs) did not alter ascites development, urinary sodium/potassium ratio, plasma aldosterone concentrations or Na,K-ATPase abundance in CCDs. Total αENaC abundance in whole kidney increased in cirrhotic mice of both genotypes and cleaved forms of α and γ ENaC increased only in ascitic mice of both genotypes. The sodium chloride cotransporter (NCC) abundance was lower in non-ascitic KO, compared to non-ascitic CTL, and increased when ascites appeared. In ascitic mice, the lack of αENaC in CDs induced an upregulation of total ENaC and NCC and correlated with the cleavage of ENaC subunits. This revealed compensatory mechanisms which could also take place when treating the patients with diuretics. These compensatory mechanisms should be considered for future development of therapeutic strategies.
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Affiliation(s)
- David Mordasini
- Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Bern University Hospital, Bern, Switzerland. .,Department of Clinical Research, University of Bern, Bern, Switzerland.
| | | | | | - Rohrbach Beatrice
- Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Bern University Hospital, Bern, Switzerland.,Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Marc P Maillard
- Service of Nephrology and Hypertension, CHUV, Rue du Bugnon 17, CH-1005, Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Rue du Bugnon 27, CH-1005, Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension, CHUV, Rue du Bugnon 17, CH-1005, Lausanne, Switzerland
| | - Geneviève Escher
- Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Bern University Hospital, Bern, Switzerland.,Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Bruno Vogt
- Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Bern University Hospital, Bern, Switzerland.,Department of Clinical Research, University of Bern, Bern, Switzerland
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Yang Y, Wei RB, Zheng XY, Qiu Q, Cui SY, Yin Z, Shi SZ, Chen XM. Effects of compound Shenhua tablet on renal tubular Na+-K+-ATPase in rats with acute ischemic reperfusion injury. Chin J Integr Med 2014; 20:200-8. [PMID: 24464369 DOI: 10.1007/s11655-014-1740-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To observe the effect of Compound Shenhua Tablet (, SHT) on the sodium-potassium- exchanging adenosinetriphosphatase (Na(+)-K(+)-ATPase) in the renal tubular epithelial cells of rats with acute ischemic reperfusion and to investigate the mechanisms underlying the effects of SHT on renal ischemic reperfusion injury (RIRI). METHODS Fifty male Wistar rats were randomly divided into the sham surgery group, model group, astragaloside group [150 mg/(kg·d)], SHT low-dose group [1.5 g/(kg·d)] and SHT high-dose group [3.0 g/(kg·d)], with 10 rats in each group. After 1 week of continuous intragastric drug administration, surgery was performed to establish the model. At either 24 or 72 h after the surgery, 5 rats in each group were sacrificed, blood biochemistry, renal pathology, immunoblot and immunohistochemical examinations were performed, and double immunofluorescence staining was observed under a laser confocal microscope. RESULTS Compared with the sham surgery group, the serum creatinine (SCr) and blood urea nitrogen (BUN) levels were significantly increased, Na(+)-K(+)-ATPase protein level was decreased, and kidney injury molecule-1 (KIM-1) protein level was increased in the model group after the surgery (P<0.01 or P<0.05). Compared with the model group, the SCr, BUN, pathological scores, Na(+)-K(+)-ATPase, and the KIM-1 protein level of the three treatment groups were significantly improved at 72 h after the surgery (P<0.05 or P<0.01). And the SCr, BUN of the SHT low- and high-dose groups, and the pathological scores of the SHT high-dose group were significantly lower than those of the astragaloside group (P<0.05). The localizations of Na(+)-K(+)-ATPase and megalin of the model group were disrupted, with the distribution areas overlapping with each other and alternately arranged. The severity of the disruption was slightly milder in three treatment groups compared with that of the model group. The results of immunofluorescence staining showed that the SHT high-dose group had a superior effect as compared with the astragaloside group and the SHT low-dose group. CONCLUSIONS The SHT effectively alleviated RIRI caused by ischemic reperfusion, promoted the recovery of the polarity of renal tubular epithelial cells, and protected the renal tubules. The therapeutic effects of SHT were superior to those of astragaloside as a single agent.
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Affiliation(s)
- Yue Yang
- State Discipline and State Key Laboratory of Kidney Disease (Chinese PLA General Hospital, 2011DAV00088), Beijing, 100853, China
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Sarin SK, Kumar C. Deeper insights into the relevance of lymphatic circulation in cirrhosis of the liver: a Trojan horse or the Holy Grail? Hepatology 2013; 58:2201-4. [PMID: 23813621 DOI: 10.1002/hep.26603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 06/17/2013] [Accepted: 06/18/2013] [Indexed: 12/07/2022]
Affiliation(s)
- Shiv Kumar Sarin
- Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India
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Endothelium/Nitric Oxide Mediates the Vasorelaxant and Antihypertensive Effects of the Aqueous Extract from the Stem Bark of Mammea africana Sabine (Guttiferae). EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:961741. [PMID: 23008745 PMCID: PMC3447406 DOI: 10.1155/2012/961741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 08/10/2012] [Indexed: 11/18/2022]
Abstract
This study evaluates the vasorelaxant and antihypertensive effects of the aqueous extract from the stem bark of M. africana (AEMA). AEMA was tested in vitro on intact or endothelium-denuded rats' aorta rings precontracted with KCl or norepinephrine in absence or in presence of L-NAME or glibenclamide. The effect of a single concentration (300 μg/mL) of AEMA was also examined on the concentration-response curve of KCl. In vivo, the antihypertensive effects of AEMA (200 mg/kg/day) were evaluated in male Wistar rats treated with L-NAME (40 mg/kg/day) for 4 weeks. AEMA relaxed aorta rings precontracted with NE or KCl with respective EC50 values of 0.36 μg/mL and 197.60 μg/mL. The destruction of endothelium or pretreatment of aorta rings with L-NAME shifted the EC50 of AEMA from 0.36 μg/mL to 40.65 μg/mL and 20.20 μg/mL, respectively. The vasorelaxant activity of M. africana was significantly inhibited in presence of glibenclamide. AEMA also significantly inhibited the concentration-response curve of KCl. Administered orally, AEMA induced acute and chronic antihypertensive effects and normalized renal NO level. These results show that the vasorelaxant activity of AEMA might be mediated by the activation of the NO-cGMP-ATP-dependent potassium channels pathway and might predominantly account for its antihypertensive effect.
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Nitric oxide-dependent bradycardia in mutant analbuminemic rats. Biochem Pharmacol 2012; 84:1062-9. [PMID: 22889827 DOI: 10.1016/j.bcp.2012.07.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 02/07/2023]
Abstract
Nagase analbuminemic rats (NAR) are natural mutant Sprague-Dawley rats which do not express albumin due to a single splice mutation in the albumin gene. We accidentally discovered that NAR have a significant bradycardia compared with wild type Sprague-Dawley rats, and the present study was carried out to investigate the mechanism of bradycardia in analbuminemic rats. In vitro studies showed that the basal spontaneous beating rate of isolated atria is similar in NAR compared with wild type animals. However, the chronotropic responsiveness of isolated atria to cholinergic stimulation was markedly increased in NAR, an effect which was prevented by incubation with a nitric oxide synthase (NOS) or guanylyl cyclase inhibitor. NAR had a significant increase in plasma nitrite/nitrate concentrations. Administration of a NOS inhibitor for 5 days normalized heart rate in NAR. The level of NOS isoforms, caveolin-1 and caveolin-3 expression in the atria was assessed by real time PCR. There was no significant difference in the expression of NOS isoforms or caveolin-3 in NAR compared with wild type controls. However, NAR exhibited a significant decrease in caveolin-1 expression in the atria. Since caveolin-1 is known to inhibit endothelial NOS activity in cardiomyocytes, we suggest that decreased caveolin-1 levels may have a role in increased nitric oxide production in NAR. Our data suggest that a NOS/cGMP-dependent mechanism might be involved in increased responsiveness to vagal stimulation and bradycardia in analbuminemic condition.
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Mechanisms associated to impaired activity of cardiac P-type ATPases in endothelial nitric oxide synthase knockout mice. J Physiol Biochem 2012; 69:207-14. [DOI: 10.1007/s13105-012-0203-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 07/25/2012] [Indexed: 11/26/2022]
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Torp M, Brønd L, Nielsen JB, Nielsen S, Christensen S, Jonassen TEN. Effects of renal denervation on the NKCC2 cotransporter in the thick ascending limb of the loop of Henle in rats with congestive heart failure. Acta Physiol (Oxf) 2012; 204:451-9. [PMID: 21854551 DOI: 10.1111/j.1748-1716.2011.02351.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM Congestive heart failure (CHF) is associated with increased renal sympathetic nerve activity and renal sodium retention. Rats with CHF display increased expression of the Na-K-2Cl cotransporter (NKCC2) in the renal medullary thick ascending limb of the loop of Henle (mTAL), and arginine vasopressin (AVP)-stimulated cAMP formation in mTAL segments is increased in rats with CHF. The aim of the study was to investigate the role of RSNA on cAMP formation and NKCC2 expression in mTAL in rats with CHF. METHODS Congestive heart failure was induced in male Wistar rats by ligation of the left anterior descending coronary artery. Bilateral surgical renal denervation (DNX) was performed 3 weeks later. Two weeks after DNX, mTAL segments were isolated and stimulated with AVP. RESULTS Congestive heart failure rats displayed increased mTAL NKCC2 expression (2.5 ± 0.5 vs. 1 ± 0.2 in Sham rats), which was abolished by DNX. Bilateral denervation decreased basal cAMP levels in unstimulated tubules from CHF rats (CHF: 12.56 ± 7.73 fmol μg(-1) protein vs. DNX-CHF: 7.94 ± 4.33; P < 0.05), as well as from Sham rats (SHAM: 4.70 ± 1.38 vs. DNX-SHAM: 2.36 ± 1.52; P < 0.05). mTAL segments from DNX-CHF and DNX-Sham rats showed decreased AVP (10(-6) M)-stimulated cAMP formation, compared with CHF (CHF: 11.92 ± 4.89 fmol μg(-1) protein vs. DNX-CHF: 4.68 ± 2.47; P < 0.05) and Sham (SHAM: 10.78 ± 5.59 vs. DNX-SHAM: 4.89 ± 2.62; P < 0.05). CONCLUSION These results indicate that the renal sympathetic nerves have an effect on NKCC2 expression in the mTAL and might have an effect on cAMP formation in the TAL in CHF.
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Affiliation(s)
- M Torp
- Department of Biomedical Sciences, University of Copenhagen, Denmark.
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Different natriuretic responses in obese and lean rats in response to nitric oxide reduction. Am J Hypertens 2011; 24:943-50. [PMID: 21562602 DOI: 10.1038/ajh.2011.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Nitric oxide (NO) is an important regulator of renal sodium transport and participates in the control of natriuresis and diuresis. In obesity, the nitric oxide bioavailability was reportedly reduced, which may contribute to the maintenance of hypertension. The aim of this study was to determine the effect of NO depletion on renal sodium handling in a model of diet-induced obesity hypertension. METHODS Obese hypertensive (obesity-prone (OP)) and lean normotensive (obesity-resistant (OR)) Sprague-Dawley rats were treated with 1.2 mg/kg/day N(G)-nitro-L-arginine-methyl ester (L-NAME) for 4 weeks to inhibit NO synthesis. Acute pressure natriuresis and diuresis were measured in response to an increase in perfusion pressure. NHE3 and Na(+), K(+)-ATPase protein expression were measured by Western blot and NHE3 activity was determined as the rate of pH change in brush border membrane vesicles. NHE3 membrane localization was determined by confocal microscopy. RESULTS L-NAME did not significantly attenuate the natriuretic and diuretic responses to increases in renal perfusion pressure (RPP) in OP rats while inducing a significant reduction in OR rats. Following chronic NO inhibition, NHE3 protein expression and activity and Na(+), K(+)-ATPase protein expression were significantly increased in the OR but not in the OP group. Immunofluorescence studies indicated that the increase in NHE3 activity could be, at least in part, due to NHE3 membrane trafficking. CONCLUSIONS Obese hypertensive rats have a weaker natriuretic response in response to NO inhibition compared to lean rats and the mechanism involves different regulation of the apical sodium exchanger NHE3 expression, activity, and trafficking.
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Nguelefack-Mbuyo EP, Dimo T, Nguelefack TB, Dongmo AB, Kamtchouing P, Kamanyi A. Renal effects of Mammea africana Sabine (Guttiferae) stem bark methanol/methylene chloride extract on L-NAME hypertensive rats. Indian J Pharmacol 2010; 42:208-13. [PMID: 20927244 PMCID: PMC2941609 DOI: 10.4103/0253-7613.68418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 07/28/2009] [Accepted: 06/19/2010] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE The present study aims at evaluating the effects of methanol/methylene chloride extract of the stem bark of Mammea africana on the renal function of L-NAME treated rats. MATERIAL AND METHODS Normotensive male Wistar rats were divided into five groups respectively treated with distilled water, L-NAME (40 mg/kg/day), L-NAME + L-arginine (100 mg/kg/day), L-NAME + captopril (20 mg/kg/day) or L-NAME + M. africana extract (200 mg/kg/day) for 30 days. Systolic blood pressure was measured before and at the end of treatment. Body weight was measured at the end of each week. Urine was collected 6 and 24 h after the first administration and further on day 15 and 30 of treatment for creatinine, sodium and potassium quantification, while plasma was collected at the end of treatment for the creatinine assay. ANOVA two way followed by Bonferonni or one way followed by Tukey were used for statistical analysis. RESULTS M. africana successfully prevented the rise in blood pressure and the acute natriuresis and diuresis induced by L-NAME. When given chronically, the extract produced a sustained antinatriuretic effect, a non-significant increase in urine excretion and reduced the glomerular hyperfiltration induced by L-NAME. CONCLUSIONS The above results suggest that the methanol/methylene chloride extract of the stem bark of M. africana may protect kidney against renal dysfunction and further demonstrate that its antihypertensive effect does not depend on a diuretic or natriuretic activity.
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Affiliation(s)
- Elvine Pami Nguelefack-Mbuyo
- Laboratory of Animal Physiology, Department of Animal Biology and Physiology, University of Yaounde I, P.O.Box 812 Yaounde, Cameroon
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Wang X, Armando I, Upadhyay K, Pascua A, Jose PA. The regulation of proximal tubular salt transport in hypertension: an update. Curr Opin Nephrol Hypertens 2009; 18:412-420. [PMID: 19654544 PMCID: PMC3722593 DOI: 10.1097/mnh.0b013e32832f5775] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE OF REVIEW Renal proximal tubular sodium reabsorption is regulated by sodium transporters, including the sodium glucose transporter, sodium amino acid transporter, sodium hydrogen exchanger isoform 3 and sodium phosphate cotransporter type 2 located at the luminal/apical membrane, and sodium bicarbonate cotransporter and Na+/K+ATPase located at the basolateral membrane. This review summarizes recent studies on sodium transporters that play a major role in the increase in blood pressure in essential/polygenic hypertension. RECENT FINDINGS Sodium transporters and Na+/K+ATPase are segregated in membrane lipid and nonlipid raft microdomains that regulate their activities and trafficking via cytoskeletal proteins. The increase in renal proximal tubule ion transport in polygenic hypertension is primarily due to increased activity of NHE3 and Cl/HCO3 exchanger at the luminal/apical membrane and a primary or secondary increase in Na+/K+ATPase activity. SUMMARY The increase in renal proximal tubule ion transport in hypertension is due to increased actions by prohypertensive factors that are unopposed by antihypertensive factors.
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Affiliation(s)
- Xiaoyan Wang
- Center for Molecular Physiology Research, Children's Research Institute, Children's National Medical Center, Washington, District of Columbia, USA
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Effects of chronic L-NAME on nitrotyrosine expression and renal vascular reactivity in rats with chronic bile-duct ligation. Clin Sci (Lond) 2008; 115:57-68. [DOI: 10.1042/cs20070312] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 12/19/2007] [Accepted: 01/09/2008] [Indexed: 11/17/2022]
Abstract
In liver cirrhosis, elevated levels of NO and ROS (reactive oxygen species) might greatly favour the generation of peroxynitrite. Peroxynitrite is a highly reactive oxidant and it can potentially alter the vascular reactivity and the function of different organs. In the present study, we evaluated whether peroxynitrite levels are related to the progression of renal vascular and excretory dysfunction during experimental cirrhosis induced by chronic BDL (bile-duct ligation) in rats. Experiments were performed at 7, 15 and 21 days after BDL in rats and in rats 21 days post-BDL chronically treated with L-NAME (NG-nitro-L-arginine methyl ester). Sodium balance, BP (blood pressure), basal RPP (renal perfusion pressure) and the renal vascular response to PHE (phenylephrine) and ACh (acetylcholine) in isolated perfused kidneys were measured. NO levels were calculated as 24-h urinary excretion of nitrites, ROS as TBARS (thiobarbituric acid-reacting substances), and peroxynitrite formation as the renal expression of nitrotyrosine. BDL rats had progressive sodium retention, and decreased BP, RPP and renal vascular responses to PHE and ACh in the time following BDL. They also had increasing levels of NO and ROS, and renal nitrotyrosine accumulation, especially in the medulla. All of these changes were either prevented or significantly decreased by chronic L-NAME administration. In conclusion, these results suggest that the increasing levels of peroxynitrite might contribute to the altered renal vascular response and sodium retention in the development of the experimental biliary cirrhosis. Moreover, the beneficial effects of decreasing NO synthesis are, at least in part, mediated by anti-peroxinitrite-related effects.
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Guo LY, Liu P. Research progress in the mechanism of renal vasoconstriction in hepatorenal syndrome. Shijie Huaren Xiaohua Zazhi 2008; 16:982-986. [DOI: 10.11569/wcjd.v16.i9.982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatorenal syndrome (HRS) is defined as the development of renal failure in patients with severe liver disease in the absence of any other identifiable cause of renal pathology. The hallmark of HRS is renal vasoconstriction. The cause of renal vasoconstriction may involve several factors: activation of renal nervous system, imbalance of renal vasoactive mediators and molecular mechanism. In this review, we summarize the above progress.
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Ackermann D, Mordasini D, Cheval L, Imbert-Teboul M, Vogt B, Doucet A. Sodium retention and ascites formation in a cholestatic mice model: role of aldosterone and mineralocorticoid receptor? Hepatology 2007; 46:173-9. [PMID: 17596887 DOI: 10.1002/hep.21699] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
UNLABELLED Renal sodium retention in experimental liver cirrhosis originates from the distal nephron sensitive to aldosterone. The aims of this study were to (1) determine the exact site of sodium retention along the aldosterone-sensitive distal nephron, and (2) to evaluate the role of aldosterone and mineralocorticoid receptor activation in this process. Liver cirrhosis was induced by bile duct ligation in either adrenal-intact or corticosteroid-clamped mice. Corticosteroid-clamp was achieved through adrenalectomy and corticosteroid supplementation with aldosterone and dexamethasone via osmotic minipumps. 24-hours renal sodium balance was evaluated in metabolic cages. Activity and expression of sodium- and potassium-dependent adenosine triphosphatase were determined in microdissected segments of nephron. Within 4-5 weeks, cirrhosis induced sodium retention in adrenal-intact mice and formation of ascites in 50% of mice. At that time, sodium- and potassium-dependent adenosine triphosphatase activity increased specifically in cortical collecting ducts. Hyperaldosteronemia was indicated by increases in urinary aldosterone excretion and in sgk1 (serum- and glucocorticoid-regulated kinase 1) mRNA expression in collecting ducts. Corticosteroid-clamp prevented induction of sgk1 but not cirrhosis-induced sodium retention, formation of ascites and stimulation of sodium- and potassium-dependent adenosine triphosphatase activity and expression (mRNA and protein) in collecting duct. These findings demonstrate that sodium retention in cirrhosis is independent of hyperaldosteronemia and of the activation of mineralocorticoid receptor. CONCLUSION Bile duct ligation in mice induces cirrhosis which, within 4-5 weeks, leads to the induction of sodium- and potassium-dependent adenosine triphosphatase in cortical collecting ducts, to renal sodium retention and to the formation of ascites. Sodium retention, ascites formation and induction of sodium- and potassium-dependent adenosine triphosphatase are independent of the activation of mineralocorticoid receptors by either aldosterone or glucocorticoids.
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Affiliation(s)
- Daniel Ackermann
- Laboratoire de Physiologie et Génomique Rénales, CNRS/UPMC UMR 7134, IFR 58, Institut des Cordeliers, Paris cedex, France
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Mani AR, Ippolito S, Ollosson R, Moore KP. Nitration of cardiac proteins is associated with abnormal cardiac chronotropic responses in rats with biliary cirrhosis. Hepatology 2006; 43:847-56. [PMID: 16557556 DOI: 10.1002/hep.21115] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Acceleration of the heart rate in response to catecholamines is impaired in cirrhosis. In this study, we tested the hypothesis that increased formation of reactive nitrogen species in biliary cirrhosis causes nitration of cardiac proteins and leads to impaired chronotropic function. Bile duct-ligated (rats with cirrhosis) or sham-operated rats were injected daily with either saline, N(G)-L-nitro-arginine methyl ester (L-NAME), or N-acetylcysteine for 7 days from week 3 to week 4 after surgery. Cardiac chronotropic responsiveness to beta-adrenergic stimulation was assessed in vitro using spontaneous beating isolated atria. Nitration of cardiac proteins was measured by mass spectrometry and located by immunogold electron microscopy. Marked impairment of chronotropic responses of isolated atria to isoproterenol was seen in rats with cirrhosis, which normalized after the administration of N-acetylcysteine or L-NAME. The levels of protein-bound nitrotyrosine in atrial tissue increased from 16 +/- 1 to 23 +/- 3 pg/microg tyrosine in rats with cirrhosis, and decreased to 15 +/- 1 and 17 +/- 1 pg/microg after treatment with L-NAME and N-acetylcysteine, respectively (P < .05). Immunogold electron microscopy demonstrated increased nitration of mitochondrial proteins in the atria of rats with cirrhosis. The plasma nitrite/nitrate levels were elevated in rats with biliary cirrhosis, and decreased after administration of L-NAME but were unchanged by N-acetylcysteine. In conclusion, abnormal cardiac chronotropic function in cirrhosis is associated with increased nitration of cardiac proteins. Two independent treatments (N-acetylcysteine and L-NAME) that decrease nitration of cardiac proteins led to normalization of cardiac responses. Nitration of critical proteins in cardiac tissue may lead to abnormal cardiac function.
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Affiliation(s)
- Ali R Mani
- The UCL Institute of Hepatology, Department of Medicine, Royal Free & University College Medical School, University College London, London, UK
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Kim SW, Wang W, Sassen MC, Choi KC, Han JS, Knepper MA, Jonassen TEN, Frøkiaer J, Nielsen S. Biphasic changes of epithelial sodium channel abundance and trafficking in common bile duct ligation-induced liver cirrhosis. Kidney Int 2006; 69:89-98. [PMID: 16374428 DOI: 10.1038/sj.ki.5000018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We hypothesize that dysregulation of the epithelial sodium channel (ENaC) may be responsible for the increased sodium retention in liver cirrhosis. Liver cirrhosis was induced by common bile duct ligation (CBDL). We examined the abundance of ENaC subunits and type 2 isoform of 11beta-hydroxysteroid dehydrogenase (11betaHSD2) in the kidney by immunoblotting and immunohistochemistry at 6 or 8 weeks after operation. At 6 weeks, cirrhotic rats had developed ascites and displayed a positive sodium balance. The urinary sodium excretion and fractional excretion of sodium were decreased, while plasma aldosterone was unchanged. The abundance of ENaC subunits was not changed in the cortex and outer stripe of the outer medulla (OSOM). In contrast, immunoperoxidase microscopy revealed an increased apical targeting of alpha-, beta- and gammaENaC in late distal convoluted tubule, connecting tubule and collecting duct. Moreover, 11betaHSD2 abundance was decreased in the cortex/OSOM and inner stripe of the outer medulla. At 8 weeks, urinary sodium excretion and fractional excretion of sodium were not changed, while the plasma aldosterone level was decreased. The expression of ENaC subunits was decreased in the cortex/OSOM. Immunoperoxidase microscopy confirmed decreased expression of ENaC subunits, whereas subcellular localization was not changed. These results suggest that increased apical targeting of ENaC subunits and diminished abundance of 11betaHSD2 may contribute to promote sodium retention in the sodium-retaining stage of liver cirrhosis (at 6 weeks). The subsequent decreased expression and reduced targeting of ENaC subunits may play a role in promoting sodium excretion in the later stage of liver cirrhosis (at 8 weeks).
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Affiliation(s)
- S W Kim
- The Water and Salt Research Center, University of Aarhus, Aarhus C, Denmark
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Fernández-Llama P, Ageloff S, Fernández-Varo G, Ros J, Wang X, Garra N, Esteva-Font C, Ballarin J, Barcelo P, Arroyo V, Stokes JB, Knepper MA, Jiménez W. Sodium retention in cirrhotic rats is associated with increased renal abundance of sodium transporter proteins. Kidney Int 2005; 67:622-30. [PMID: 15673309 DOI: 10.1111/j.1523-1755.2005.67118.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Liver cirrhosis with ascites is associated with a decrease in renal sodium excretion and therefore sodium retention. METHODS In this paper, we utilize transporter-specific antibodies to address the hypothesis that dysregulation of one or more sodium transporters or channels is associated with sodium chloride (NaCl) retention in a rat model of cirrhosis induced by repeated exposure to carbon tetrachloride. Age-matched controls and cirrhotic rats were pair fed to ensure identical NaCl and water intake for 4 days prior to euthanasia for quantitative immunoblotting studies. RESULTS AND CONCLUSION The rats manifested marked extracellular fluid volume expansion with massive ascites. Plasma aldosterone levels were markedly elevated. Analysis of immunoblots revealed marked increases in the abundances of both of the major aldosterone-sensitive apical transport proteins of the renal tubule, namely the thiazide-sensitive NaCl cotransporter NCC and the epithelial sodium channel alpha subunit (alpha-ENaC). These results are consistent with an important role for hyperaldosteronism in the pathogenesis of sodium retention and ascites formation in cirrhosis. In addition, we observed a large decrease in cortical NHE3 abundance (proximal tubule) and a large increase in NKCC2 abundance (thick ascending limb), potentially shifting premacula densa sodium absorption from proximal tubule to loop of Henle (which powers urinary concentration and dilution).
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