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Blaustein MP, Hamlyn JM. Sensational site: the sodium pump ouabain-binding site and its ligands. Am J Physiol Cell Physiol 2024; 326:C1120-C1177. [PMID: 38223926 PMCID: PMC11193536 DOI: 10.1152/ajpcell.00273.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/22/2023] [Accepted: 01/10/2024] [Indexed: 01/16/2024]
Abstract
Cardiotonic steroids (CTS), used by certain insects, toads, and rats for protection from predators, became, thanks to Withering's trailblazing 1785 monograph, the mainstay of heart failure (HF) therapy. In the 1950s and 1960s, we learned that the CTS receptor was part of the sodium pump (NKA) and that the Na+/Ca2+ exchanger was critical for the acute cardiotonic effect of digoxin- and ouabain-related CTS. This "settled" view was upended by seven revolutionary observations. First, subnanomolar ouabain sometimes stimulates NKA while higher concentrations are invariably inhibitory. Second, endogenous ouabain (EO) was discovered in the human circulation. Third, in the DIG clinical trial, digoxin only marginally improved outcomes in patients with HF. Fourth, cloning of NKA in 1985 revealed multiple NKA α and β subunit isoforms that, in the rodent, differ in their sensitivities to CTS. Fifth, the NKA is a cation pump and a hormone receptor/signal transducer. EO binding to NKA activates, in a ligand- and cell-specific manner, several protein kinase and Ca2+-dependent signaling cascades that have widespread physiological effects and can contribute to hypertension and HF pathogenesis. Sixth, all CTS are not equivalent, e.g., ouabain induces hypertension in rodents while digoxin is antihypertensinogenic ("biased signaling"). Seventh, most common rodent hypertension models require a highly ouabain-sensitive α2 NKA and the elevated blood pressure is alleviated by EO immunoneutralization. These numerous phenomena are enabled by NKA's intricate structure. We have just begun to understand the endocrine role of the endogenous ligands and the broad impact of the ouabain-binding site on physiology and pathophysiology.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
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Horesh N, Pelov I, Pogodin I, Zannadeh H, Rosen H, Mikhrina AL, Dvela-Levitt M, Sampath VP, Lichtstein D. Involvement of the Na +, K +-ATPase α1 Isoform and Endogenous Cardiac Steroids in Depression- and Manic-like Behaviors. Int J Mol Sci 2024; 25:1644. [PMID: 38338921 PMCID: PMC10855204 DOI: 10.3390/ijms25031644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/18/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
Bipolar disorder (BD) is a severe and common chronic mental illness characterized by recurrent mood swings between depression and mania. The biological basis of the disease is poorly understood, and its treatment is unsatisfactory. Na+, K+-ATPase is a major plasma membrane transporter and signal transducer. The catalytic α subunit of this enzyme is the binding site for cardiac steroids. Three α isoforms of the Na+, K+-ATPase are present in the brain. Previous studies have supported the involvement of the Na+, K+-ATPase and endogenous cardiac steroids (ECS) in the etiology of BD. Decreased brain ECS has been found to elicit anti-manic and anti-depressive-like behaviors in mice and rats. However, the identity of the specific α isoform involved in these behavioral effects is unknown. Here, we demonstrated that decreasing ECS through intracerebroventricular (i.c.v.) administration of anti-ouabain antibodies (anti-Ou-Ab) decreased the activity of α1+/- mice in forced swimming tests but did not change the activity in wild type (wt) mice. This treatment also affected exploratory and anxiety behaviors in α1+/- but not wt mice, as measured in open field tests. The i.c.v. administration of anti-Ou-Ab decreased brain ECS and increased brain Na+, K+-ATPase activity in wt and α1+/- mice. The serum ECS was lower in α1+/- than wt mice. In addition, a study in human participants demonstrated that serum ECS significantly decreased after treatment. These results suggest that the Na+, K+-ATPase α1 isoform is involved in depressive- and manic-like behaviors and support that the Na+, K+-ATPase/ECS system participates in the etiology of BD.
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Affiliation(s)
- Noa Horesh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Ilana Pelov
- Jerusalem Mental Health Center, Eitanim Psychiatric Hospital, Jerusalem 91060, Israel;
| | - Ilana Pogodin
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Hiba Zannadeh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Haim Rosen
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel;
| | - Anastasiia Leonidovna Mikhrina
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Moran Dvela-Levitt
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel;
| | - Vishnu Priya Sampath
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - David Lichtstein
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
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Jiang K, He T, Ji Y, Zhu T, Jiang E. The perspective of hypertension and salt intake in Chinese population. Front Public Health 2023; 11:1125608. [PMID: 36875386 PMCID: PMC9981806 DOI: 10.3389/fpubh.2023.1125608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/01/2023] [Indexed: 02/19/2023] Open
Abstract
Salt intake is too high nowadays. It has been widely recognized that there is a close relationship between hypertension (HTN) and dietary salt intake. Investigations reveal that long-term high salt intake, mainly sodium intake, induces a relevant increase in blood pressure in hypertensive and normotensive individuals. According to most scientific evidence, a diet with high salt intake in public increases cardiovascular risk, salted-related HTN, and other HTN-associated outcomes. Given the clinical importance, this review aims to present the prevalence of HTN and trends in salt intake in the Chinese population and will comprehensively discuss the risk factors, causes, and mechanisms of the association between salt intake and HTN. The review also highlights the education of Chinese people regarding salt intake and the cost-effectiveness of salt reduction from a global perspective. Finally, the review will emphasize the need to customize the unique Chinese practices to reduce salt intake and how awareness changes people's eating lifestyle and helps adopt diet salt reduction strategies.
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Affiliation(s)
- Kexin Jiang
- Institute of Nursing and Health, Henan University, Kaifeng, China
| | - Tingting He
- Department of Basic Nursing, Henan Technical Institute, Zhengzhou, China
| | - Yongzhi Ji
- Institute of Nursing and Health, Henan University, Kaifeng, China
| | - Tao Zhu
- Department of Geriatrics, Kaifeng Traditional Chinese Medicine Hospital, Kaifeng, China
| | - Enshe Jiang
- Institute of Nursing and Health, Henan University, Kaifeng, China.,Department of Scientific Research, Scope Research Institute of Electrophysiology, Kaifeng, China
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Patel N, Yaqoob MM, Aksentijevic D. Cardiac metabolic remodelling in chronic kidney disease. Nat Rev Nephrol 2022; 18:524-537. [DOI: 10.1038/s41581-022-00576-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 11/09/2022]
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Grigorova YN, Juhasz O, Long JM, Zernetkina VI, Hall ML, Wei W, Morrell CH, Petrashevskaya N, Morrow A, LaNasa KH, Bagrov AY, Rapp PR, Lakatta EG, Fedorova OV. Effect of Cardiotonic Steroid Marinobufagenin on Vascular Remodeling and Cognitive Impairment in Young Dahl-S Rats. Int J Mol Sci 2022; 23:4563. [PMID: 35562955 PMCID: PMC9101263 DOI: 10.3390/ijms23094563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/17/2022] [Accepted: 04/17/2022] [Indexed: 02/04/2023] Open
Abstract
The hypertensive response in Dahl salt-sensitive (DSS) rats on a high-salt (HS) diet is accompanied by central arterial stiffening (CAS), a risk factor for dementia, and heightened levels of a prohypertensive and profibrotic factor, the endogenous Na/K-ATPase inhibitor marinobufagenin (MBG). We studied the effect of the in vivo administration of MBG or HS diet on blood pressure (BP), CAS, and behavioral function in young DSS rats and normotensive Sprague-Dawley rats (SD), the genetic background for DSS rats. Eight-week-old male SD and DSS rats were given an HS diet (8% NaCl, n = 18/group) or a low-salt diet (LS; 0.1% NaCl, n = 14-18/group) for 8 weeks or MBG (50 µg/kg/day, n = 15-18/group) administered via osmotic minipumps for 4 weeks in the presence of the LS diet. The MBG-treated groups received the LS diet. The systolic BP (SBP); the aortic pulse wave velocity (aPWV), a marker of CAS; MBG levels; spatial memory, measured by a water maze task; and tissue collection for the histochemical analysis were assessed at the end of the experiment. DSS-LS rats had higher SBP, higher aPWV, and poorer spatial memory than SD-LS rats. The administration of stressors HS and MBG increased aPWV, SBP, and aortic wall collagen abundance in both strains vs. their LS controls. In SD rats, HS or MBG administration did not affect heart parameters, as assessed by ECHO vs. the SD-LS control. In DSS rats, impaired whole-heart structure and function were observed after HS diet administration in DSS-HS vs. DSS-LS rats. MBG treatment did not affect the ECHO parameters in DSS-MBG vs. DSS-LS rats. The HS diet led to an increase in endogenous plasma and urine MBG levels in both SD and DSS groups. Thus, the prohypertensive and profibrotic effect of HS diet might be partially attributed to an increase in MBG. The prohypertensive and profibrotic functions of MBG were pronounced in both DSS and SD rats, although quantitative PCR revealed that different profiles of profibrotic genes in DSS and SD rats was activated after MBG or HS administration. Spatial memory was not affected by HS diet or MBG treatment in either SD or DSS rats. Impaired cognitive function was associated with higher BP, CAS, and cardiovascular remodeling in young DSS-LS rats, as compared to young SD-LS rats. MBG and HS had similar effects on the cardiovascular system and its function in DSS and SD rats, although the rate of change in SD rats was lower than in DSS rats. The absence of a cumulative effect of increased aPWV and BP on spatial memory can be explained by the cerebrovascular and brain plasticity in young rats, which help the animals to tolerate CAS elevated by HS and MBG and to counterbalance the profibrotic effect of heightened MBG.
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Affiliation(s)
- Yulia N. Grigorova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Ondrej Juhasz
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Jeffrey M. Long
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (J.M.L.); (A.M.); (K.H.L.); (P.R.R.)
| | - Valentina I. Zernetkina
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Mikayla L. Hall
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Wen Wei
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Christopher H. Morrell
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Natalia Petrashevskaya
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Audrey Morrow
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (J.M.L.); (A.M.); (K.H.L.); (P.R.R.)
| | - Katherine H. LaNasa
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (J.M.L.); (A.M.); (K.H.L.); (P.R.R.)
| | - Alexei Y. Bagrov
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Peter R. Rapp
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (J.M.L.); (A.M.); (K.H.L.); (P.R.R.)
| | - Edward G. Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
| | - Olga V. Fedorova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (Y.N.G.); (O.J.); (V.I.Z.); (M.L.H.); (W.W.); (C.H.M.); (N.P.); (A.Y.B.); (E.G.L.)
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A New Method to Estimate Inhibition Percentage of Endogenous Digitalis in Patients with Pre-eclampsia. Rep Biochem Mol Biol 2022; 11:138-145. [PMID: 35765519 PMCID: PMC9208553 DOI: 10.52547/rbmb.11.1.138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/29/2021] [Indexed: 01/11/2023]
Abstract
Background Pre-eclampsia is an idiopathic pregnancy disorder characterized by appearance proteinuria and hypertension, with poorly understood etiology. It has been linked to a variety of system abnormalities, including ion transport disorders in neonatal, maternal, and placental cell lines. A new method was described to evaluate the inhibition percentage of endogenous digitalis in plasma of pre-eclampsia patients compared with normal pregnancies, with the estimation of sensitivity and specificity of the proposed test. Methods This was a case-control study consisting of 130 cases that were divided into three groups, 55 normal pregnancies (positive control), 30 non-pregnant women (negative control), and 45 pre-eclampsia (patients). The new method included the estimation of the percentage inhibition of endogenous digitalis by measuring specific enzyme activity of Na-K ATPase for the patient and positive control. The results were analyzed using the statistical package for social sciences (SPSS®) software version 26.0. A p-value of≤ 0.05 was considered significant. Results In the pre-eclampsia patient, the specific activity of Na-K ATPase was significantly lower with mean= 0.239 mg/g±0.043 compared to the control group which was 0.397 mg/g±0.021, p< 0.001. While the result of inhibition percentage of endogenous digitalis showed significantly higher in the pre-eclampsia patient (mean= 35.852 mg/g %±2.692%) compared to the control group (mean= 17.964%±1.784), with a p< 0.001. Conclusion Pre-eclampsia is linked with lower erythrocyte sodium pump activity significantly in pre-eclampsia patients than in normal pregnancies. Also, results show the inhibited percentage of endogenous digitalis elevation in patients with pre-eclampsia compared with normal pregnancy.
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Tegin G, Gao Y, Hamlyn JM, Clark BJ, El-Mallakh RS. Inhibition of endogenous ouabain by atrial natriuretic peptide is a guanylyl cyclase independent effect. PLoS One 2021; 16:e0260131. [PMID: 34793577 PMCID: PMC8601428 DOI: 10.1371/journal.pone.0260131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 11/03/2021] [Indexed: 12/15/2022] Open
Abstract
Background Endogenous ouabain (EO) and atrial natriuretic peptide (ANP) are important in regulation of sodium and fluid balance. There is indirect evidence that ANP may be involved in the regulation of endogenous cardenolides. Methods H295R are human adrenocortical cells known to release EO. Cells were treated with ANP at physiologic concentrations or vehicle (0.1% DMSO), with or without guanylyl cyclase inhibitor 1,2,4 oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Cyclic guanosine monophosphate (cGMP), the intracellular second messenger of ANP, was measured by a chemiluminescent immunoassay and EO was measured by radioimmunoassay of C18 extracted samples. Results EO secretion is inhibited by ANP treatment, with the most prolonged inhibition (90 min vs ≤ 60 min) occurring at physiologic ANP concentrations (50 pg/mL). Inhibition of guanylyl cyclase with ODQ, also reduces EO secretion. The inhibitory effects on EO release in response to cotreatment with ANP and ODQ appeared to be additive. Conclusions ANP inhibits basal EO secretion, and it is unlikely that this is mediated through ANP-A or ANP-B receptors (the most common natriuretic peptide receptors) or their cGMP second messenger; the underlying mechanisms involved are not revealed in the current studies. The role of ANP in the control of EO synthesis and secretion in vivo requires further investigation.
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Affiliation(s)
- Gulay Tegin
- Department of Psychiatry and Behavioral Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - Yonglin Gao
- Department of Psychiatry and Behavioral Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - John M. Hamlyn
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Mississippi, United States of America
| | - Barbara J. Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky, United States of America
| | - Rif S. El-Mallakh
- Department of Psychiatry and Behavioral Sciences, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
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Li Y, Lyu Y, Huang J, Huang K, Yu J. Transcriptome sequencing reveals high-salt diet-induced abnormal liver metabolic pathways in mice. BMC Gastroenterol 2021; 21:335. [PMID: 34454434 PMCID: PMC8397858 DOI: 10.1186/s12876-021-01912-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 08/19/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Although salt plays an important role in maintaining the normal physiological metabolism of the human body, many abnormalities in the liver caused by a high-salt diet, especially with normal pathological results, are not well characterized. METHODS Eight-week-old female C57BL/6 mice were randomly divided into a normal group and a high salt group. These groups were then fed with normal or sodium-rich chow (containing 6% NaCl) for 6 weeks. Liver injury was evaluated, and the influences of a high-salt diet on the liver were analyzed by transcriptome sequencing at the end of week 6. RESULTS We found that although no liver parenchymal injury could be found after high-salt feeding, many metabolic abnormalities had formed based on transcriptome sequencing results. GO and KEGG enrichment analyses of differentially expressed genes revealed that at least 15 enzymatic activities and the metabolism of multiple substances were affected by a high-salt diet. Moreover, a variety of signaling and metabolic pathways, as well as numerous biological functions, were involved in liver dysfunction due to a high-salt diet. This included some known pathways and many novel ones, such as retinol metabolism, linoleic acid metabolism, steroid hormone biosynthesis, and signaling pathways. CONCLUSIONS A high-salt diet can induce serious abnormal liver metabolic activities in mice at the transcriptional level, although substantial physical damage may not yet be visible. This study, to our knowledge, was the first to reveal the impact of a high-salt diet on the liver at the omics level, and provides theoretical support for potential clinical risk evaluation, pathogenic mechanisms, and drug design for combating liver dysfunction. This study also provides a serious candidate direction for further research on the physiological impacts of high-salt diets.
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Affiliation(s)
- Yanping Li
- Department of Gastroenterology, Civil Aviation General Hospital, No. 1, Gaojingjia, Chaoyang District, China
| | - Yufei Lyu
- Beijing Institute of Biotecnology, No. 20, Dongda Street, Fengtai District, Beijing, China
| | - Jing Huang
- Beijing Institute of Biotecnology, No. 20, Dongda Street, Fengtai District, Beijing, China
| | - Kun Huang
- Department of Gastroenterology, Civil Aviation General Hospital, No. 1, Gaojingjia, Chaoyang District, China.
| | - Jiufei Yu
- Department of Gastroenterology, Civil Aviation General Hospital, No. 1, Gaojingjia, Chaoyang District, China.
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Yang JL, Yang MD, Chen JC, Lu KW, Huang YP, Peng SF, Chueh FS, Liu KC, Lin TS, Chen PY, Chen WJ. Ouabain Induces DNA Damage in Human Osteosarcoma U-2 OS Cells and Alters the Expression of DNA Damage and DNA Repair-associated Proteins. In Vivo 2021; 35:2687-2696. [PMID: 34410957 DOI: 10.21873/invivo.12552] [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: 06/08/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM Ouabain, isolated from natural plants, exhibits anticancer activities; however, no report has presented its mechanism of DNA damage induction in human osteosarcoma cancer cells in vitro. The aim of this study was to investigate whether ouabain induces DNA damage and repair, accompanied with molecular pathways in human osteosarcoma cancer U-2 OS cells in vitro. MATERIALS AND METHODS The percentage of viable cell number was measured by flow cytometric assay; DNA damage was assayed by DAPI staining, comet assay, and agarose gel electrophoresis. DNA damage and repair associated protein expressions were assayed by western blotting assays. RESULTS Ouabain reduced total cell viability, induced chromatin condensation, DNA fragmentation, and DNA damage in U-2 OS cells. Ouabain increased p-ATMSer1981, p-ATRSer428, and p53 at 2.5-10 μM, increased p-p53Ser15 at 10 μM; however, it decreased p-MDM2Ser166 at 2.5-10 μM. Ouabain increased p-H2A.XSer139, MDC-1, and PARP at 2.5-10 μM and BRCA1 at 5-10 μM; however, it decreased DNA-PK and MGMT at 2.5-10 μM in U-2 OS cells at 48 h treatment. Ouabain promoted expression and nuclear translocation of p-H2A.XSer139 in U-2 OS cells and this was confirmed by confocal laser microscopy. CONCLUSION Ouabain reduced total viable cell number through triggering DNA damage and altering the protein expression of DNA damage and repair system in U-2 OS cells in vitro.
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Affiliation(s)
- Jiun-Long Yang
- Department of Nursing, Saint Mary's Junior College of Medicine, Nursing and Management, Yilan, Taiwan, R.O.C
| | - Mei-Due Yang
- Department of Surgery, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Jaw-Chyun Chen
- Department of Medicinal Botany and Health Applications, Da-Yeh University, Changhua, Taiwan, R.O.C
| | - Kung-Wen Lu
- College of Chinese Medicine, School of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C
| | - Yi-Ping Huang
- Department of Physiology, School of Medicine, China Medical University, Taichung, Taiwan, R.O.C
| | - Shu-Fen Peng
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, R.O.C.,Department of Medical Research, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Fu-Shin Chueh
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan, R.O.C
| | - Kuo-Ching Liu
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan, R.O.C
| | - Tzu-Shun Lin
- Department of Nursing, Saint Mary's Junior College of Medicine, Nursing and Management, Yilan, Taiwan, R.O.C.,Department of Pharmacy, Saint Mary's Hospital Luodong, Yilan, Taiwan, R.O.C
| | - Po-Yuan Chen
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, R.O.C.;
| | - Wei-Jen Chen
- Department of Orthopedics, Chang Bing Show-Chwan Memorial Hospital, Changhua, Taiwan, R.O.C.; .,Department of Orthopedics, Show-Chwan Memorial Hospital, Changhua, Taiwan, R.O.C
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Venkatakrishnan K, Chiu HF, Wang CK. Impact of functional foods and nutraceuticals on high blood pressure with a special focus on meta-analysis: review from a public health perspective. Food Funct 2021; 11:2792-2804. [PMID: 32248209 DOI: 10.1039/d0fo00357c] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In recent times many researchers are expressing immense interest in nutraceuticals and functional foods for combating various diseases or abnormal conditions, especially against hypertension (HT). Persistent HT is medically referred to as chronic high blood pressure (BP) and considered to be one of the major risk factors for the deadliest diseases including cardiovascular disease (CVD) and cerebrovascular diseases. Hence HT poses a serious socio-economic burden worldwide, particularly to developing countries. The current treatment strategy for HT includes standard anti-hypertensive drugs, which are associated with many adverse effects and lower drug adherence rates. Therefore, an alternative or complementary natural therapy (functional foods or nutraceuticals or dietary supplements) would be the alternate choice along with a modified lifestyle pattern that might help to manage or combat HT and its related complications. During this review, the author would like to shed light on the basic science behind HT including pathophysiology and the impact of dietary salt on HT and the impact of various functional foods or nutraceuticals against HT in humans (meta-analysis and systemic review). This contribution gives a better idea (public health perspective) for choosing the best functional foods/nutraceuticals for the prevention, management or delaying the onset of HT and its associated conditions along with modified lifestyle patterns and standard anti-hypertensive drugs.
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Affiliation(s)
- Kamesh Venkatakrishnan
- School of Nutrition, Chung Shan Medical University, 110, Sec. 1, Jianguo North Road, Taichung City-40201, Taiwan, Republic of China.
| | - Hui-Fang Chiu
- Department of Chinese Medicine, Taichung Hospital Ministry of Health and Welfare, Taichung-40301, Taiwan, Republic of China
| | - Chin-Kun Wang
- School of Nutrition, Chung Shan Medical University, 110, Sec. 1, Jianguo North Road, Taichung City-40201, Taiwan, Republic of China.
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11
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Valenzuela PL, Carrera-Bastos P, Gálvez BG, Ruiz-Hurtado G, Ordovas JM, Ruilope LM, Lucia A. Lifestyle interventions for the prevention and treatment of hypertension. Nat Rev Cardiol 2020; 18:251-275. [PMID: 33037326 DOI: 10.1038/s41569-020-00437-9] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2020] [Indexed: 02/07/2023]
Abstract
Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.
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Affiliation(s)
| | - Pedro Carrera-Bastos
- Centre for Primary Health Care Research, Lund University/Region Skane, Skane University Hospital, Malmö, Sweden
| | - Beatriz G Gálvez
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain
| | - Gema Ruiz-Hurtado
- Research Institute of the Hospital Universitario 12 de Octubre (imas12), Madrid, Spain.,CIBER-CV, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - José M Ordovas
- Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.,IMDEA Alimentacion, Madrid, Spain
| | - Luis M Ruilope
- Research Institute of the Hospital Universitario 12 de Octubre (imas12), Madrid, Spain.,CIBER-CV, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Alejandro Lucia
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain. .,Research Institute of the Hospital Universitario 12 de Octubre (imas12), Madrid, Spain.
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12
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Jafarnejad S, Mirzaei H, Clark CCT, Taghizadeh M, Ebrahimzadeh A. The hypotensive effect of salt substitutes in stage 2 hypertension: a systematic review and meta-analysis. BMC Cardiovasc Disord 2020; 20:98. [PMID: 32106813 PMCID: PMC7047420 DOI: 10.1186/s12872-020-01347-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 01/20/2020] [Indexed: 12/11/2022] Open
Abstract
Background Hypertension (HTN) is a ubiquitous risk factor for numerous non-communicable diseases, including cardiovascular disease and stroke. There are currently no wholly effective pharmacological therapies for subjects with HTN. However, salt substitutes have emerged as a potential therapy for the treatment of HTN. The aim of the present study was to assess the effect of salt substitutes on reducing systolic blood pressure (SBP) and diastolic BP (DBP), following a meta-analysis of randomized controlled trials. Methods Studies were found via systematic searches of the Pubmed/Medline, Scopus, Ovid, Google Scholar and Cochrane library. Ten studies, comprised of 11 trials and 1119 participants, were included in the meta-analysis. Results Pooled weighted mean differences showed significant reductions of SBP (WMD − 8.87 mmHg; 95% CI − 11.19, − 6.55, p < 0.001) and DBP (WMD − 4.04 mmHg; 95% CI − 5.70, − 2.39) with no statistically significant heterogeneity between the 11 included comparisons of SBPs and DBPs. The stratified analysis of trials based on the mean age of participants showed a significant reduction in the mean difference of SBP in both adults (< 65 years old) and elderly (≥65 years old). However, the DBP-lowering effect of salt substitutes was only observed in adult patients (WMD − 4.22 mmHg; 95% CI − 7.85, − 0.58), but not in the elderly subjects. Conclusions These findings suggest that salt-substitution strategies could be used for lowering SBP and DBP in patients with stage 2 HTN; providing a nutritional platform for the treatment, amelioration, and prevention of HTN.
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Affiliation(s)
- Sadegh Jafarnejad
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan, University of Medical Sciences, Kashan, IR, Iran.
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan, University of Medical Sciences, Kashan, IR, Iran
| | - Cain C T Clark
- Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, UK
| | - Mohsen Taghizadeh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan, University of Medical Sciences, Kashan, IR, Iran
| | - Armin Ebrahimzadeh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan, University of Medical Sciences, Kashan, IR, Iran
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13
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Influence of Endogenous Cardiac Glycosides, Digoxin, and Marinobufagenin in the Physiology of Epithelial Cells. Cardiol Res Pract 2019; 2019:8646787. [PMID: 32089875 PMCID: PMC7024086 DOI: 10.1155/2019/8646787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Cardiac glycosides are a group of compounds widely known for their action in cardiac tissue, some of which have been found to be endogenously produced (ECG). We have previously studied the effect of ouabain, an endogenous cardiac glycoside, on the physiology of epithelial cells, and we have shown that in concentrations in the nanomolar range, it affects key properties of epithelial cells, such as tight junction, apical basolateral polarization, gap junctional intercellular communication (GJIC), and adherent junctions. In this work, we study the influence of digoxin and marinobufagenin, two other endogenously expressed cardiac glycosides, on GJIC as well as the degree of transepithelial tightness due to tight junction integrity (TJ). We evaluated GJIC by dye transfer assays and tight junction integrity by transepithelial electrical resistance (TER) measurements, as well as immunohistochemistry and western blot assays of expression of claudins 2 and 4. We found that both digoxin and marinobufagenin improve GJIC and significantly enhance the tightness of the tight junctions, as evaluated from TER measurements. Immunofluorescence assays show that both compounds promote enhanced basolateral localization of claudin-4 but not claudin 2, while densitometric analysis of western blot assays indicate a significantly increased expression of claudin 4. These changes, induced by digoxin and marinobufagenin on GJIC and TER, were not observed on MDCK-R, a modified MDCK cell line that has a genetically induced insensitive α1 subunit, indicating that Na-K-ATPase acts as a receptor mediating the actions of both ECG. Plus, the fact that the effect of both cardiac glycosides was suppressed by incubation with PP2, an inhibitor of c-Src kinase, PD98059, an inhibitor of mitogen extracellular kinase-1 and Y-27632, a selective inhibitor of ROCK, and a Rho-associated protein kinase, indicate altogether that the signaling pathways involved include c-Src and ERK1/2, as well as Rho-ROCK. These results widen and strengthen our general hypothesis that a very important physiological role of ECG is the control of the epithelial phenotype and the regulation of cell-cell contacts.
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14
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Intracerebroventricular injection of ouabain causes mania-like behavior in mice through D2 receptor activation. Sci Rep 2019; 9:15627. [PMID: 31666560 PMCID: PMC6821712 DOI: 10.1038/s41598-019-52058-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/11/2019] [Indexed: 01/07/2023] Open
Abstract
Intracerebroventricular (ICV) administration of ouabain, an inhibitor of the Na, K-ATPase, is an approach used to study the physiological functions of the Na, K-ATPase and cardiotonic steroids in the central nervous system, known to cause mania-like hyperactivity in rats. We describe a mouse model of ouabain-induced mania-like behavior. ICV administration of 0.5 µl of 50 µM (25 pmol, 14.6 ng) ouabain into each lateral brain ventricle results in increased locomotor activity, stereotypical behavior, and decreased anxiety level an hour at minimum. Fast-scan cyclic voltammetry showed that administration of 50 µM ouabain causes a drastic drop in dopamine uptake rate, confirmed by elevated concentrations of dopamine metabolites detected in the striatum 1 h after administration. Ouabain administration also caused activation of Akt, deactivation of GSK3β and activation of ERK1/2 in the striatum of ouabain-treated mice. All of the abovementioned effects are attenuated by haloperidol (70 µg/kg intraperitoneally). Observed effects were not associated with neurotoxicity, since no dystrophic neuron changes in brain structures were demonstrated by histological analysis. This newly developed mouse model of ouabain-induced mania-like behavior could provide a perspective tool for studying the interactions between the Na,K-ATPase and the dopaminergic system.
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15
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Askari A. The sodium pump and digitalis drugs: Dogmas and fallacies. Pharmacol Res Perspect 2019; 7:e00505. [PMID: 31360524 PMCID: PMC6639696 DOI: 10.1002/prp2.505] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 11/29/2022] Open
Abstract
The sodium pump (Na/K-ATPase) is a plasma membrane enzyme that transports Na+ and K+ against their physiological gradients in most eukaryotic cells. Besides pumping ions, the enzyme may also interact with neighboring proteins to activate cell signaling pathways that regulate cell growth. Digitalis drugs, useful for the treatment of heart failure and atrial arrhythmias, inhibit the pumping function of Na/K-ATPase and stimulate its signaling function. In the current field of research on the sodium pump and digitalis drugs, some issues that are commonly accepted to be well established are not so, and this may impede progress. Here, several such issues are identified, their histories are discussed, and their open discussions are urged. The covered unsettled questions consist of (a) the suggested hormonal role of endogenous digitalis compounds; (b) the specificity of Na/K-ATPase as the receptor for digitalis compounds; (c) the relevance of the positive inotropic action of digitalis to its use for the treatment of heart failure; (d) the conflicting findings on digitalis-induced signaling function of Na/K-ATPase; and (e) the uncertainties about the structure of Na/K-ATPase in the native cell membrane.
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Affiliation(s)
- Amir Askari
- Department of Cancer Biology, College of Medicine and Life SciencesUniversity of ToledoToledoOhio
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16
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Strauss M, Smith W, Wei W, Fedorova OV, Schutte AE. Autonomic activity and its relationship with the endogenous cardiotonic steroid marinobufagenin: the African-PREDICT study. Nutr Neurosci 2019; 23:849-859. [PMID: 30614779 DOI: 10.1080/1028415x.2018.1564985] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Aim: Marinobufagenin (MBG), a cardiotonic steroid and a natriuretic hormone, is elevated in response to high salt diet consumption. In animal models salt intake stimulates adrenocortical MBG secretion via increased angiotensin II, sympathetic activity and aldosterone. No evidence in humans exists to suggest the involvement of the angiotensinergic-sympatho-excitatory pathway in MBG production. We investigated whether MBG is related to indices of autonomic activity in men and women. Methods: This cross-sectional study included 680 black and white, men and women from the African-PREDICT study (aged 20-30 years). Continuous 24 hr ECG recordings were used to obtain low and high frequency (LF, HF) heart rate variability (HRV). We measured 24 hr urinary MBG excretion and serum aldosterone. Results: We found a positive association of MBG excretion with estimated salt intake (P < 0.001) and aldosterone (P < 0.001) in women and men. In women only, a positive relationship was evident between MBG excretion and LF HRV in multivariate adjusted regression analyses (Adj. R 2 = 0.33; β = 0.11; P = 0.030). In men, MBG excretion associated positively with HF HRV in similar regression analyses (R 2 = 0.36; β = 0.12; P = 0.034). Sex-specific results were corroborated only in blacks, namely, a positive association of MBG excretion with LF HRV in black women (R 2 = 0.38; β = 0.13; P = 0.036), and negative association with HF HRV in black men (R 2 = 0.40; β = 0.18; P = 0.045). No relationships were evident in white women (P = 0.58) or men (P = 0.27). Conclusion: Our findings in this human cohort support suggested mechanisms whereby MBG is elevated as a result of increased salt intake, including autonomic activity, previously demonstrated in Dahl salt-sensitive hypertension.
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Affiliation(s)
- Michél Strauss
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.,MRC Research Unit: Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Wen Wei
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Aletta E Schutte
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.,MRC Research Unit: Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
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17
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Dietary Sodium Restriction Reduces Arterial Stiffness, Vascular TGF-β-Dependent Fibrosis and Marinobufagenin in Young Normotensive Rats. Int J Mol Sci 2018; 19:ijms19103168. [PMID: 30326586 PMCID: PMC6214093 DOI: 10.3390/ijms19103168] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/14/2018] [Accepted: 10/10/2018] [Indexed: 12/27/2022] Open
Abstract
High salt (HS) intake stimulates the production of marinobufagenin (MBG), an endogenous steroidal Na/K-ATPase ligand, which activates profibrotic signaling. HS is accompanied by a blood pressure (BP) increase in salt-sensitive hypertension, but not in normotensive animals. Here, we investigated whether HS stimulates MBG production and activates transforming growth factor-beta (TGF-β) profibrotic signaling in young normotensive rats, and whether these changes can be reversed by reducing salt to a normal salt (NS) level. Three-month old male Sprague–Dawley rats received NS for 4 and 8 weeks (0.5% NaCl; NS4 and NS8), or HS for 4 and 8 weeks (4% NaCl; HS4 and HS8), or HS for 4 weeks followed by NS for 4 weeks (HS4/NS4), n = 8/group. Systolic BP (SBP), pulse wave velocity (PWV), MBG excretion, aortic collagen 1α2, collagen 4α1 and TGF-β, Smad2, Smad3, Fli-1 mRNA, and total collagen abundance were measured at baseline (BL), and on weeks 4 and 8. Statistical analysis was performed using one-way ANOVA. SBP was not affected by HS (125 ± 5 and 126 ± 6 vs. 128 ± 7 mmHg, HS4 and HS8 vs. BL, p > 0.05). HS increased MBG (164 ± 19 vs. 103 ± 19 pmol/24 h/kg, HS4 vs. BL, p < 0.05) and PWV (3.7 ± 0.2 vs. 2.7 ± 0.2 m/s, HS4 vs. NS4, p < 0.05). HS8 was associated with a further increase in MBG and PWV, with an increase in aortic Col1a2 80%), Col4a1 (50%), Tgfb1 (30%), Smad2 (30%) and Smad3 (45%) mRNAs, and aortic wall collagen (180%) vs. NS8 (all p < 0.05). NS following HS downregulated HS-induced factors: in HS4/NS4, the MBG level was 91 ± 12 pmol/24 h/kg (twofold lower than HS8, p < 0.01), PWV was 3.7 ± 0.3 vs. 4.7 ± 0.2 m/s (HS4/NS4 vs. HS8, p < 0.05), aortic wall Tgfb1, Col1a2, Col4a1, Smad2, Smad3 mRNAs, and collagen abundance were reversed by salt reduction to the BL levels (p < 0.05). HS was associated with an activation of TGF-β signaling, aortic fibrosis and aortic stiffness accompanied by an MBG increase in the absence of SBP changes in young normotensive rats. The reduction of dietary salt following HS decreased MBG, PWV, aortic wall collagen and TGF-β. Thus, HS-induced aortic stiffness in normotensive animals occurred in the context of elevated MBG, which may activate SMAD-dependent TGF-β pro-fibrotic signaling. This data suggests that a decrease in salt consumption could help to restore aortic elasticity and diminish the risk of cardiovascular disease by reducing the production of the pro-fibrotic factor MBG.
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18
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Kanbay M, Aslan G, Afsar B, Dagel T, Siriopol D, Kuwabara M, Incir S, Camkiran V, Rodriguez‐Iturbe B, Lanaspa MA, Covic A, Johnson RJ. Acute effects of salt on blood pressure are mediated by serum osmolality. J Clin Hypertens (Greenwich) 2018; 20:1447-1454. [PMID: 30232829 PMCID: PMC8030773 DOI: 10.1111/jch.13374] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/06/2018] [Accepted: 07/15/2018] [Indexed: 02/06/2023]
Abstract
It is classically thought that it is the amount of salt that is critical for driving acute blood pressure responses. However, recent studies suggest that blood pressure responses, at least acutely, may relate to changes in serum osmolality. Here, we test the hypothesis that acute blood pressure responses to salt can be altered by concomitant water loading. Ten healthy patients free of any disease and medication underwent 4 interventions each a week apart in which they took 300 mL of lentil soup with no salt (visit 1), lentil soup with 3 g salt (visit 2), or lentil soup with 3 g salt and 500 mL water (visit 3) or 750 mL water (visit 4). At each visit, hourly blood measurements and blood pressure measurements (baseline, 1st, 2nd, 3rd, and 4th hour) were performed and plasma osmolarity, sodium and copeptin levels were measured. Patients receiving the 3 g salt showed a 6 mOsm/L change in osmolality with a 2.5 mmol/L change in plasma sodium and 10 mm Hg rise in systolic blood pressure at 2 hours. When the same patients drank salty soup with water, the changes in plasma osmolarity, plasma sodium, and blood pressure were prevented. The ability to raise blood pressure acutely with salt appears dependent on changes in plasma osmolality rather than the amount of salt. Our findings suggest that concurrent intake of water must be considered when evaluating the role of salt in blood pressure.
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Affiliation(s)
- Mehmet Kanbay
- Division of Nephrology, Department of MedicineKoc University School of MedicineIstanbulTurkey
| | - Gamze Aslan
- Department of CardiologyKoc University HospitalIstanbulTurkey
| | - Baris Afsar
- Division of Nephrology, Department of Internal MedicineSuleyman Demirel University School of MedicineIspartaTurkey
| | - Tuncay Dagel
- Division of Nephrology, Department of MedicineKoc University School of MedicineIstanbulTurkey
| | - Dimitrie Siriopol
- Department of NephrologyUniversity of Medicine and Pharmacy "Gr. T. Popa"lasiRomania
| | - Masanari Kuwabara
- Division of Renal Diseases and Hypertension, School of MedicineUniversity of Colorado DenverAuroraColorado
- Department of CardiologyToranomon HospitalTokyoJapan
| | - Said Incir
- Department of BiochemistryKoc University HospitalIstanbulTurkey
| | - Volkan Camkiran
- Department of CardiologyKoc University HospitalIstanbulTurkey
| | - Bernardo Rodriguez‐Iturbe
- Instituto Venezolano de Investigaciones CientÍficas (IVIC‐Zulia), Nephrology Service Hospital Universitario, Universidad del ZuliaMaracaiboVenezuela
| | - Miguel A. Lanaspa
- Division of Renal Diseases and Hypertension, School of MedicineUniversity of Colorado DenverAuroraColorado
| | - Adrian Covic
- Department of NephrologyUniversity of Medicine and Pharmacy "Gr. T. Popa"lasiRomania
| | - Richard J. Johnson
- Division of Renal Diseases and Hypertension, School of MedicineUniversity of Colorado DenverAuroraColorado
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19
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Endogenous Ouabain and Related Genes in the Translation from Hypertension to Renal Diseases. Int J Mol Sci 2018; 19:ijms19071948. [PMID: 29970843 PMCID: PMC6073363 DOI: 10.3390/ijms19071948] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 01/22/2023] Open
Abstract
The endogenous ouabain (EO) is a steroid hormone secreted by the adrenal gland with cardio-tonic effects. In this article, we have reviewed and summarized the most recent reports about EO, particularly with regard to how it may interact with specific genetic backgrounds. We have focused our attention on the EO’s potential pathogenic role in several diseases, including renal failure, essential hypertension and heart failure. Notably, these reports have demonstrated that EO acts as a pro-hypertrophic and growth-promoting hormone, which might lead to a cardiac remodeling affecting cardiovascular functions and structures. In addition, a possible role of EO in the development of acute kidney injury has been hypothesized. During the last decays, many important improvements permitted a deeper understanding of EO’s metabolisms and functions, including the characteristics of its receptor and the effects of its activation. Such progresses indicated that EO has significant implications in the pathogenesis of many common diseases. The patho-physiological role of EO in the development of hypertension and other cardiac and renal complications have laid the basis for the development of a new selective compound that could selectively modulate the genetic and molecular mechanisms involved in EO’s action. It is evident that the knowledge of EO has incredibly increased; however, many important areas remain to be further investigated.
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20
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Cheng X, Song Y, Wang Y. pNaKtide ameliorates renal interstitial fibrosis through inhibition of sodium-potassium adenosine triphosphatase-mediated signaling pathways in unilateral ureteral obstruction mice. Nephrol Dial Transplant 2018; 34:242-252. [DOI: 10.1093/ndt/gfy107] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/17/2018] [Indexed: 01/02/2023] Open
Affiliation(s)
- Xi Cheng
- Renal Division, Department of Medicine, Peking University First Hospital
- Institute of Nephrology, Peking University
- Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education
| | - Yi Song
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Yu Wang
- Renal Division, Department of Medicine, Peking University First Hospital
- Institute of Nephrology, Peking University
- Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education
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21
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Lenaerts C, Bond L, Tuytten R, Blankert B. Revealing of endogenous Marinobufagin by an ultra-specific and sensitive UHPLC-MS/MS assay in pregnant women. Talanta 2018; 187:193-199. [PMID: 29853035 DOI: 10.1016/j.talanta.2018.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 01/24/2023]
Abstract
Marinobufagenin (MBG) is a bufadienolide cardiac inotrope implicated in volume expansion-mediated hypertensive states including essential hypertension and preeclampsia (PE). Endogenous MBG is an inhibitor of the α1-isoform of Na+,K+-ATPase with vasoconstrictive and cardiotonic properties, causing hypertension and natriuresis. Elevated endogenous MBG-like material levels have been described by immunoassays in salt-sensitive pregnant and preeclamptic rats as well as in preeclamptic human patients. The rise of endogenous MBG-like material appears prior the development of the main symptoms of PE, leading us to consider MBG as one of the potential biomarkers for PE. The weak specificity and the high variability of the published immunoassays gives no certification about endogenous MBG existence. This led us to set-up a highly specific and sensitive analytical method to detect MBG in plasma at low levels relying on liquid chromatography combined to mass spectrometry (UHPLC-MS/MS) with recording of 7 highly specific MRM transitions for MBG. Pure MBG standard used in the method development was obtained by purification from the Bufo marinus toad venom. d3-25-hydroxyvitamin D3 was used as internal standard. An increasing organic gradient with mobile phase A and B composed of 97:3 (v/v) H2O: MeOH and 50:45:5 (v/v/v) MeOH:IPA:H2O at pH 4.5 respectively was used on a Pursuit 3 PFP column (100 mm × 3 mm; 3 µm) to allow elution and separation of the plasmatic compounds. Chromatographic analyses of plasma samples were preceded by a precipitation of proteins pretreatment. The developed UHPLC-MS/MS assay has been applied to early-pregnant women plasma samples allowing us to investigate MBG plasma levels. Thanks to the high specificity of the assay we were able to authenticate and certify the presence of endogenous MBG in early-pregnant women plasma with the use of the 7 selected specific mass transitions. These pioneering preliminary results are giving a promising perspective for early preeclampsia risk assessment in pregnant women.
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Affiliation(s)
- Charline Lenaerts
- Laboratory of Pharmaceutical Analysis, Faculty of medicine and pharmacy, Research Institute for Health Sciences and Technology, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Liz Bond
- Metabolomic Diagnostics, Little Island, Cork, Ireland
| | - Robin Tuytten
- Metabolomic Diagnostics, Little Island, Cork, Ireland
| | - Bertrand Blankert
- Laboratory of Pharmaceutical Analysis, Faculty of medicine and pharmacy, Research Institute for Health Sciences and Technology, University of Mons, Place du Parc 20, 7000 Mons, Belgium.
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22
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Lopachev AV, Abaimov DA, Fedorova TN, Lopacheva OM, Akkuratova NV, Akkuratov EE. Cardiotonic Steroids as Potential Endogenous Regulators in the Nervous System. NEUROCHEM J+ 2018. [DOI: 10.1134/s1819712418010087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Estapé ES, González-Sepúlveda L, Wei W, Rodríguez-Rivera I, Torres-Negrón I. Low to Normal Plasma Levels of Marinobufagenin 24 Hours or More after an Ischemic Stroke: A Pilot Study. ACTA ACUST UNITED AC 2018; 4. [PMID: 30957100 DOI: 10.23937/2572-4142.1510006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Background Numerous studies have demonstrated a strong relationship between circulating levels of marinobufagenin (MBG) and salt-sensitivity. Since salt-sensitive hypertensives have increased plasma levels of MBG and are known to be at a higher risk of having cardiovascular events, stroke and increased mortality, we evaluated the possibility of an association between MBG and ischemic stroke. In this pilot study, we determined plasma MBG levels in patients after surviving an ischemic stroke compared to similar age and gender groups of treated hypertensives and normotensive controls. Methods We measured plasma MBG levels in a total of 40 participants subdivided into three groups: After an ischemic stroke STR (n = 13), participants with a diagnosis of hypertension receiving blood pressure medication HT (n = 14) and normotensive control subjects CTL (n = 13). We used inferential statistics (parametric or non-parametric) and ordered logistic regression models (unadjusted and adjusted) and all statistical analyses were performed using Stata 14. Results We did not include a subject from the CTL group because of a diagnosis of glucose-6-phosphate dehydrogenase deficiency and an extreme plasma MBG value of 2,246 pmol/L. Participants' mean age was 60.4 ± 11.5 years; 56% were male. There was no significant difference between study groups (p > 0.05) for gender, age, and body mass index. HbA1c levels were significantly higher in the STR as compared to the CTL p < 0.05). In the STR group MBG levels were below the normal range (< 200 pmol/L) in three (23%), eight (61%) were in the normal range (200-400 pmol/L), while two (16%) had increased MBG values (> 400 pmol/L). Also, among the STR, the plasma MBG levels did not differ between those receiving and not receiving thrombolytic therapy (p > 0.05). From the 14 HT participants, six (43%) had MBG plasma levels within the normal range, and eight (57%) had high concentrations (> 400 pmol/L). Four (29%) of the treated hypertensives had extreme MBG levels (> 1,000 pmol/L) and normal values of blood pressure. Conclusion There was no significant elevation of plasma MBG in survivors 24 h or more after an ischemic stroke. The extreme values of plasma MBG in 29% of the treated hypertensives suggests the presence of salt-sensitivity and a possible side effect of a specific combination of medications. Both of these findings contribute new knowledge to the design of studies to define if there is an MBG molecular mechanism underlying the complex associations among salt-sensitivity, hypertension, and ischemic stroke.
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Affiliation(s)
- Estela S Estapé
- University of Puerto Rico, Medical Sciences Campus, Puerto Rico.,San Juan Bautista School of Medicine, Caguas, Puerto Rico
| | | | - Wen Wei
- National Institute of Aging, National Institutes of Health, Baltimore, MD, USA
| | | | - Ivette Torres-Negrón
- Universidad del Turabo, Ana G Méndez University System, Puerto Rico.,Universidad Metropolitana, Ana G Méndez University System, Puerto Rico
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Blaustein MP. The pump, the exchanger, and the holy spirit: origins and 40-year evolution of ideas about the ouabain-Na + pump endocrine system. Am J Physiol Cell Physiol 2017; 314:C3-C26. [PMID: 28971835 DOI: 10.1152/ajpcell.00196.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two prescient 1953 publications set the stage for the elucidation of a novel endocrine system: Schatzmann's report that cardiotonic steroids (CTSs) are all Na+ pump inhibitors, and Szent-Gyorgi's suggestion that there is an endogenous "missing screw" in heart failure that CTSs like digoxin may replace. In 1977 I postulated that an endogenous Na+ pump inhibitor acts as a natriuretic hormone and simultaneously elevates blood pressure (BP) in salt-dependent hypertension. This hypothesis was based on the idea that excess renal salt retention promoted the secretion of a CTS-like hormone that inhibits renal Na+ pumps and salt reabsorption. The hormone also inhibits arterial Na+ pumps, elevates myocyte Na+ and promotes Na/Ca exchanger-mediated Ca2+ gain. This enhances vasoconstriction and arterial tone-the hallmark of hypertension. Here I describe how those ideas led to the discovery that the CTS-like hormone is endogenous ouabain (EO), a key factor in the pathogenesis of hypertension and heart failure. Seminal observations that underlie the still-emerging picture of the EO-Na+ pump endocrine system in the physiology and pathophysiology of multiple organ systems are summarized. Milestones include: 1) cloning the Na+ pump isoforms and physiological studies of mutated pumps in mice; 2) discovery that Na+ pumps are also EO-triggered signaling molecules; 3) demonstration that ouabain, but not digoxin, is hypertensinogenic; 4) elucidation of EO's roles in kidney development and cardiovascular and renal physiology and pathophysiology; 5) discovery of "brain ouabain", a component of a novel hypothalamic neuromodulatory pathway; and 6) finding that EO and its brain receptors modulate behavior and learning.
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Affiliation(s)
- Mordecai P Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine , Baltimore, Maryland
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25
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Blaustein MP. How does pressure overload cause cardiac hypertrophy and dysfunction? High-ouabain affinity cardiac Na + pumps are crucial. Am J Physiol Heart Circ Physiol 2017; 313:H919-H930. [PMID: 28733446 PMCID: PMC5792198 DOI: 10.1152/ajpheart.00131.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022]
Abstract
Left ventricular hypertrophy is frequently observed in hypertensive patients and is believed to be due to the pressure overload and cardiomyocyte stretch. Three recent reports on mice with genetically engineered Na+ pumps, however, have demonstrated that cardiac ouabain-sensitive α2-Na+ pumps play a key role in the pathogenesis of transaortic constriction-induced hypertrophy. Hypertrophy was delayed/attenuated in mice with mutant, ouabain-resistant α2-Na+ pumps and in mice with cardiac-selective knockout or transgenic overexpression of α2-Na+ pumps. The latter, seemingly paradoxical, findings can be explained by comparing the numbers of available (ouabain-free) high-affinity (α2) ouabain-binding sites in wild-type, knockout, and transgenic hearts. Conversely, hypertrophy was accelerated in α2-ouabain-resistant (R) mice in which the normally ouabain-resistant α1-Na+ pumps were mutated to an ouabain-sensitive (S) form (α1S/Sα2R/R or "SWAP" vs. wild-type or α1R/R α2S/S mice). Furthermore, transaortic constriction-induced hypertrophy in SWAP mice was prevented/reversed by immunoneutralizing circulating endogenous ouabain (EO). These findings show that EO and its receptor, ouabain-sensitive α2, are critical factors in pressure overload-induced cardiac hypertrophy. This complements reports linking elevated plasma EO to hypertension, cardiac hypertrophy, and failure in humans and elucidates the underappreciated role of the EO-Na+ pump pathway in cardiovascular disease.
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Affiliation(s)
- Mordecai P. Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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26
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Dmitrieva RI, Cranford SM, Doris PA. Genetic Control of Serum Marinobufagenin in the Spontaneously Hypertensive Rat and the Relationship to Blood Pressure. J Am Heart Assoc 2017; 6:JAHA.117.006704. [PMID: 28982675 PMCID: PMC5721872 DOI: 10.1161/jaha.117.006704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND We have investigated serum levels of immunoreactive marinobufagenin (MBG) in 16- to 20-week-old spontaneously hypertensive rats (SHRs)-A3 and in the normotensive Wistar-Kyoto (WKY) rat strain in the absence of salt loading, and we have investigated the genetic control of serum MBG. METHODS AND RESULTS We genotyped the F2 progeny of an SHR-A3×WKY intercross using a genome-wide panel of 253 single-nucleotide polymorphism markers that were dimorphic between SHR-A3 and WKY and measured serum MBG by ELISA. Serum MBG levels were lower in SHR-A3 than WKY rats (0.39±0.07 and 1.27±0.40 nmol/L, respectively), suggesting that MBG may not play a role in the markedly divergent blood pressure measured by telemetry in rats of these 2 strains (SHR-A3 and WKY, 198.3±4.43 and 116.8±1.51 mm Hg, respectively). The strain difference in serum MBG was investigated to determine whether genomic regions influencing MBG might be identified by genetic mapping. Quantitative trait locus mapping indicated a single locus influencing serum MBG in the region of chromosome 6q12. Homozygosity of WKY alleles at this locus was associated with increased serum MBG levels. We surveyed whole genome sequences from our SHR-A3 and WKY lines, seeking coding sequence variation between SHR-A3 and WKY within the mapped locus that might explain the inherited strain difference in serum MBG. CONCLUSIONS We identified amino acid substitution in the sterol transport protein Abcg5, present in SHR-A3, but absent in WKY, that is a potential mechanism influencing MBG levels.
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Affiliation(s)
- Renata I Dmitrieva
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, TX
| | - Stacy M Cranford
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, TX
| | - Peter A Doris
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, TX
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27
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Leenen FHH, Blaustein MP, Hamlyn JM. Update on angiotensin II: new endocrine connections between the brain, adrenal glands and the cardiovascular system. Endocr Connect 2017; 6:R131-R145. [PMID: 28855243 PMCID: PMC5613704 DOI: 10.1530/ec-17-0161] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/30/2017] [Indexed: 12/11/2022]
Abstract
In the brain, angiotensinergic pathways play a major role in chronic regulation of cardiovascular and electrolyte homeostasis. Increases in plasma angiotensin II (Ang II), aldosterone, [Na+] and cytokines can directly activate these pathways. Chronically, these stimuli also activate a slow neuromodulatory pathway involving local aldosterone, mineralocorticoid receptors (MRs), epithelial sodium channels and endogenous ouabain (EO). This pathway increases AT1R and NADPH oxidase subunits and maintains/further increases the activity of angiotensinergic pathways. These brain pathways not only increase the setpoint of sympathetic activity per se, but also enhance its effectiveness by increasing plasma EO and EO-dependent reprogramming of arterial and cardiac function. Blockade of any step in this slow pathway or of AT1R prevents Ang II-, aldosterone- or salt and renal injury-induced forms of hypertension. MR/AT1R activation in the CNS also contributes to the activation of sympathetic activity, the circulatory and cardiac RAAS and increase in circulating cytokines in HF post MI. Chronic central infusion of an aldosterone synthase inhibitor, MR blocker or AT1R blocker prevents a major part of the structural remodeling of the heart and the decrease in LV function post MI, indicating that MR activation in the CNS post MI depends on aldosterone, locally produced in the CNS. Thus, Ang II, aldosterone and EO are not simply circulating hormones that act on the CNS but rather they are also paracrine neurohormones, locally produced in the CNS, that exert powerful effects in key CNS pathways involved in the long-term control of sympathetic and neuro-endocrine function and cardiovascular homeostasis.
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Affiliation(s)
- Frans H H Leenen
- Brain and Heart Research GroupUniversity of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Mordecai P Blaustein
- Department of PhysiologyUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of MedicineUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
| | - John M Hamlyn
- Department of PhysiologyUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
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28
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Gable M, Ellis L, Fedorova OV, Bagrov AY, Askari A. Comparison of Digitalis Sensitivities of Na +/K +-ATPases from Human and Pig Kidneys. ACS OMEGA 2017; 2:3610-3615. [PMID: 28782051 PMCID: PMC5537699 DOI: 10.1021/acsomega.7b00591] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/06/2017] [Indexed: 05/16/2023]
Abstract
Digitalis drugs are selective inhibitors of the plasma membrane Na+/K+-ATPase. There are many studies on molecular mechanisms of digitalis interaction with purified pig kidney enzyme, with the tacit assumption that it is a good model of human kidney enzyme. However, previous studies on crude or recombinant human kidney enzymes are limited, and have not resulted in consistent findings on their digitalis sensitivities. Hence, we prepared comparably purified enzymes from human and pig kidneys and determined inhibitory constants of digoxin, ouabain, ouabagenin, bufalin, and marinobufagenin (MBG) on enzyme activity under optimal turnover conditions. We found that each compound had the same potency against the two enzymes, indicating that (i) the pig enzyme is an appropriate model of the human enzyme, and (ii) prior discrepant findings on human kidney enzymes were either due to structural differences between the natural and recombinant enzymes or because potencies were determined using binding constants of digitalis for enzymes under nonphysiological conditions. In conjunction with previous findings, our newly determined inhibitory constants of digitalis compounds for human kidney enzymes indicate that (i) of the compounds that have long been advocated to be endogenous hormones, only bufalin and MBG may act as such at kidney tubules, and (ii) beneficial effects of digoxin, the only digitalis with extensive clinical use, does not involve its inhibitory effect on renal tubular Na+/K+-ATPase.
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Affiliation(s)
- Marjorie
E. Gable
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
| | - Linda Ellis
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
| | - Olga V. Fedorova
- Laboratory
of Cardiovascular Science, National Institute of Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Alexei Y. Bagrov
- Laboratory
of Cardiovascular Science, National Institute of Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
- Sechenov
Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg 194223, Russia
| | - Amir Askari
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
- E-mail: . Phone: 419-383-3982
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29
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Salt and essential hypertension: pathophysiology and implications for treatment. ACTA ACUST UNITED AC 2017; 11:385-391. [DOI: 10.1016/j.jash.2017.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/13/2017] [Accepted: 04/05/2017] [Indexed: 12/24/2022]
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30
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Liu J, Yan Y, Nie Y, Shapiro JI. Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress. Antioxidants (Basel) 2017; 6:E18. [PMID: 28257114 PMCID: PMC5384181 DOI: 10.3390/antiox6010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/10/2017] [Accepted: 02/22/2017] [Indexed: 02/07/2023] Open
Abstract
Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Yanling Yan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Ying Nie
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Joseph I Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
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31
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Abstract
Significant hemodynamic changes ensue with aging, leading to an ever-growing epidemic of hypertension. Alterations in central arterial properties play a major role in these hemodynamic changes. These alterations are characterized by an initial decline in aortic distensibility and an increase of diastolic blood pressure, followed by a sharp increase in pulse wave velocity (PWV), and an increase in pulse pressure (PP) beyond the sixth decade. However, the trajectories of PWV and PP diverge with advancing age. There is an increased prevalence of salt-sensitive hypertension with advancing age that is, in part, mediated by marinobufagenin, an endogenous sodium pump ligand.
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Affiliation(s)
- Majd AlGhatrif
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA; Department of Medicine, Johns Hopkins Bayview Medical Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Alexei Y Bagrov
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA.
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Shah PT, Martin R, Yan Y, Shapiro JI, Liu J. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis. Front Physiol 2016; 7:256. [PMID: 27445847 PMCID: PMC4923243 DOI: 10.3389/fphys.2016.00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/11/2016] [Indexed: 01/01/2023] Open
Abstract
Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).
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Affiliation(s)
- Preeya T Shah
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Rebecca Martin
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
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33
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Martin R, Shapiro JI. Role of adipocytes in hypertension. World J Hypertens 2016; 6:66-75. [DOI: 10.5494/wjh.v6.i2.66] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/02/2016] [Indexed: 02/06/2023] Open
Abstract
Although it has known for some time that obesity is associated with salt sensitivity and hypertension, recent data suggests that the adipocyte may actually be the proximate cause of this physiological changes. In the following review, the data demonstrating this association as well as the potentially operative pathophysiological mechanisms are reviewed and discussed.
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Acsai K, Ördög B, Varró A, Nánási PP. Role of the dysfunctional ryanodine receptor - Na(+)-Ca(2+)exchanger axis in progression of cardiovascular diseases: What we can learn from pharmacological studies? Eur J Pharmacol 2016; 779:91-101. [PMID: 26970182 DOI: 10.1016/j.ejphar.2016.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 12/28/2022]
Abstract
Abnormal Ca(2+)homeostasis is often associated with chronic cardiovascular diseases, such as hypertension, heart failure or cardiac arrhythmias, and typically contributes to the basic ethiology of the disease. Pharmacological targeting of cardiac Ca(2+)handling has great therapeutic potential offering invaluable options for the prevention, slowing down the progression or suppression of the harmful outcomes like life threatening cardiac arrhythmias. In this review we outline the existing knowledge on the involvement of malfunction of the ryanodine receptor and the Na(+)-Ca(2+)exchanger in disturbances of Ca(2+)homeostasis and discuss important proof of concept pharmacological studies targeting these mechanisms in context of hypertension, heart failure, atrial fibrillation and ventricular arrhythmias. We emphasize the promising results of preclinical studies underpinning the potential benefits of the therapeutic strategies based on ryanodine receptor or Na(+)-Ca(2+)exchanger inhibition.
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Affiliation(s)
- Károly Acsai
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Szeged, Hungary
| | - Balázs Ördög
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Faculty of Medicine, Szeged, Hungary
| | - András Varró
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Szeged, Hungary; Department of Pharmacology and Pharmacotherapy, University of Szeged, Faculty of Medicine, Szeged, Hungary
| | - Péter P Nánási
- Department of Physiology, University of Debrecen, Debrecen, Hungary; Department of Dentistry, University of Debrecen, Debrecen, Hungary.
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Yan Y, Shapiro JI. The physiological and clinical importance of sodium potassium ATPase in cardiovascular diseases. Curr Opin Pharmacol 2016; 27:43-9. [PMID: 26891193 PMCID: PMC5161351 DOI: 10.1016/j.coph.2016.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/14/2016] [Accepted: 01/29/2016] [Indexed: 12/14/2022]
Abstract
The Na/K-ATPase has been extensively studied, but it is only recently that its role as a scaffolding and signaling protein has been identified. It has been identified that cardiotonic steroids (CTS) such as digitalis mediate signal transduction through the Na/K-ATPase in a process found to result in the generation of reactive oxygen species (ROS). As these ROS also appear capable of initiating this signal cascade, a feed forward amplification process has been postulated and subsequently implicated in some disease pathways including uremic cardiomyopathy.
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Affiliation(s)
- Yanling Yan
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA
| | - Joseph I Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA.
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36
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Rogachevskii IV, Shelykh TN, Podzorova SA, Krylov BV, Plakhova VB. Ab initio conformational analysis of marinobufagenin molecule and molecular targets of the action of cardiotonic steroids. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2015. [DOI: 10.1134/s1070428015110172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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37
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Feniman-De-Stefano GMM, Zanati-Basan SG, De Stefano LM, Xavier PS, Castro AD, Caramori JCT, Barretti P, Franco RJDS, Martin LC. Spironolactone is secure and reduces left ventricular hypertrophy in hemodialysis patients. Ther Adv Cardiovasc Dis 2015; 9:158-67. [PMID: 26116627 DOI: 10.1177/1753944715591448] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES There is recent evidence that aldosterone play a role in the pathogenesis of cardiovascular disease in dialysis patients, which leads to the opportunity to block its actions for the benefit of these patients. In nondialytic chronic kidney disease, spironolactone was safe and effective in reducing left ventricular hypertrophy. However, routine use has been precluded in hemodialysis patients due to the risk of hyperkalemia. The aim of this study is to verify the safety and efficacy in regression of left ventricular hypertrophy with spironolactone in hemodialysis patients undergoing pharmacotherapeutic monitoring. METHODS We performed a controlled, randomized, double blind study evaluating 17 hemodialysis patients who received spironolactone at a dose of 12.5 mg titrated, in the second week, to 25 mg of spironolactone or placebo. The patients were treated for 6 months. RESULTS The groups were composed of eight patients (intervention) and nine patients (control). These groups did not differ in their baseline characteristics. The group receiving spironolactone had a left ventricular mass index reduction from 77 ± 14.6 g/m(2.7) to 69 ± 10.5 g/m(2.7), p < 0.04, whereas in placebo group there was an increase from 71 ± 14.2 g/m(2.7) to 74 ± 17.4 g/m(2.7). Systolic or diastolic blood pressure did not change during the study. Potassium did not differ statistically between groups in all instances. CONCLUSION Spironolactone treatment in hemodialysis patients was secure and effective in regression of left ventricular hypertrophy, a major risk factor for cardiovascular events in these patients. This effect occurred in spite of blood pressure stability. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT01128101.
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Affiliation(s)
| | | | | | | | - Ana Dóris Castro
- Dpto de Medicamentos - Faculdade de Ciências Farmacêuticas - UNESP, Brazil
| | | | - Pasqual Barretti
- Dpto de Clínica Médica da Faculdade de Medicina de Botucatu - UNESP, Brazil
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Estape ES, Torres-Negron I, Gonzalez L, Martinez-Maldonado M. A New Animal Model to Study Endogenous Cardiotonic Steroids and the Progression of Cardiovascular Events in Salt-Sensitive Hypertension. INTERNATIONAL ARCHIVES OF TRANSLATIONAL MEDICINE 2015; 1:002. [PMID: 26457335 PMCID: PMC4599712 DOI: 10.23937/2572-4142.1510002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Dahl salt-sensitive rat is a well-established model to study essential hypertension. We first described a subgroup of these rats based on the unique response pattern in systolic blood pressure during the first weeks of exposure to a high salt diet that included cataract formation. We classified this group as cataract-prone Dahl salt-sensitive rat. We also were able to predict and prevent cataract formation in these rats. Further studies showed an inhibition of lens Na, K-ATPase activity which may be in part responsible for the cataract formation. Other studies in Dahl salt-sensitive rats maintained on a high salt diet have also shown decreased Na, K-ATPase activity in several tissues and increased levels of endogenous circulating Na, K pump inhibitors. For over 20 years, endogenous cardiotonic steroids have been postulated to inhibit Na, K-ATPase in both humans as well as in experimental animal models of hypertension. Recent findings have shown results suggesting that there are several forms of cardiotonic steroids with minor differences in structural functionalities, site of production, and specific pump selectivity. We present original data that supports a role for cardiotonic steroids in disease progression related to increased salt-sensitivity. We found increased levels of free endogenous cardiotonic steroids in those rats that were classified as cataract-prone according to their initial systolic blood pressure response to a high salt intake when compared to non-cataract prone Dahl salt-sensitive rats and their control Dahl salt-resistant rats. The cataract-prone Dahl salt-sensitive rat is an animal model that can help and contribute to open a new door to possibly elucidate the role of endogenous cardiotonic steroids in the pathogenesis and progression of diseases related to salt-sensitive hypertension.
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Affiliation(s)
- Estela S Estape
- School of Health Professions, Medical Sciences Campus, University of Puerto Rico, Puerto Rico
| | - Ivette Torres-Negron
- School of Environmental Affairs, Universidad Metropolitana, Ana G Méndez University System, Puerto Rico
| | - Lorena Gonzalez
- Puerto Rico Clinical and Translational Research Consortium, Medical Sciences Campus, University of Puerto Rico, Puerto Rico
| | - Manuel Martinez-Maldonado
- Consultant, University of Puerto Rico, Medical Sciences Campus, Puerto Rico Clinical and Translational Research Consortium, Puerto Rico
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Gonano LA, Petroff MV. Subcellular Mechanisms Underlying Digitalis-Induced Arrhythmias: Role of Calcium/Calmodulin-Dependent Kinase II (CaMKII) in the Transition from an Inotropic to an Arrhythmogenic Effect. Heart Lung Circ 2014; 23:1118-24. [DOI: 10.1016/j.hlc.2014.07.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/03/2014] [Accepted: 07/23/2014] [Indexed: 11/27/2022]
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Ghadhanfar E, Al-Bader M, Turcani M. Wistar rats resistant to the hypertensive effects of ouabain exhibit enhanced cardiac vagal activity and elevated plasma levels of calcitonin gene-related peptide. PLoS One 2014; 9:e108909. [PMID: 25279791 PMCID: PMC4184851 DOI: 10.1371/journal.pone.0108909] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 08/28/2014] [Indexed: 01/03/2023] Open
Abstract
Ouabain is a cardiac glycoside produced in the adrenal glands and hypothalamus. It affects the function of all cells by binding to Na+/K+-ATPase. Several lines of evidence suggest that endogenous ouabain could be involved in the pathogenesis of essential (particularly, salt-sensitive) hypertension. However, information regarding the postulated hypertensive effect of the long-term administration of low-dose exogenous ouabain is inconsistent. This study was designed to help settle this controversy through the use of telemetric monitoring of arterial blood pressure and to elucidate the ouabain-induced alterations that could either promote or prevent hypertension. Ouabain (63 and 324 µg/kg/day) was administered subcutaneously to male Wistar rats. Radiotelemetry was used to monitor blood pressure, heart rate and measures of cardiovascular variability and baroreflex sensitivity. The continuous administration of ouabain for 3 months did not elevate arterial blood pressure. The low-frequency power of systolic pressure variability, urinary excretion of catecholamines, and cardiovascular response to restraint stress and a high-salt diet as well as the responsiveness to α1-adrenergic stimulation were all unaltered by ouabain administration, suggesting that the activity of the sympathetic nervous system was not increased. However, surrogate indices of cardiac vagal nerve activity based on heart rate variability were elevated. Molecular remodeling in mesenteric arteries that could support the development of hypertension (increased expression of the genes for the Na+/Ca2+ exchanger and Na+/K+-ATPase α2 isoform) was not evident. Instead, the plasma level of vasodilatory calcitonin gene-related peptide (CGRP) significantly rose from 55 (11, SD) in the control group to 89 (20, SD) pg/ml in the ouabain-treated rats (PTukey's = 18.10(-5)). These data show that long-term administration of exogenous ouabain does not necessarily cause hypertension in rodents. The augmented parasympathetic activity and elevated plasma level of CGRP could be linked to the missing hypertensive effect of ouabain administration.
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Affiliation(s)
- Elham Ghadhanfar
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Maie Al-Bader
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Marian Turcani
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
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Song D, Du T. Ammonium activates ouabain-activated signalling pathway in astrocytes: therapeutic potential of ouabain antagonist. Curr Neuropharmacol 2014; 12:334-41. [PMID: 25342941 PMCID: PMC4207073 DOI: 10.2174/1570159x12666140828222115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 01/16/2023] Open
Abstract
The causal role of ammonium in hepatic encephalopathy was identified in 1930s. Astroglial cells are primary cellular elements of hepatic encephalopathy which conceptually, can be considered a toxic astrogliopathology. Previously we have reported that acute exposure to ammonium activated ouabain/Na,K-ATPase signalling pathway, which includes Src, EGF receptor, Raf, Ras, MEK and ERK1/2. Chronic incubation of astrocytes with ammonium increased production of endogenous ouabain-like compound. Ouabain antagonist canrenone abolished effects of ammonium on astrocytic swelling, ROS production, and upregulation of gene expression and function of TRPC1 and Cav1.2. However, ammonium induces multiple pathological modifications in astrocytes, and some of them may be not related to this signalling pathway. In this review, we focus on the effect of ammonium on ouabain/Na,K-ATPase signalling pathway and its involvement in ammonium-induced ROS production, cell swelling and aberration of Ca(2+) signals in astrocytes. We also briefly discuss Na,K-ATPase, EGF receptor, endogenous ouabain and ouabain antagonist.
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Affiliation(s)
- Dan Song
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
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Khundmiri SJ. Advances in understanding the role of cardiac glycosides in control of sodium transport in renal tubules. J Endocrinol 2014; 222:R11-24. [PMID: 24781255 DOI: 10.1530/joe-13-0613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cardiotonic steroids have been used for the past 200 years in the treatment of congestive heart failure. As specific inhibitors of membrane-bound Na(+)/K(+) ATPase, they enhance cardiac contractility through increasing myocardial cell calcium concentration in response to the resulting increase in intracellular Na concentration. The half-minimal concentrations of cardiotonic steroids required to inhibit Na(+)/K(+) ATPase range from nanomolar to micromolar concentrations. In contrast, the circulating levels of cardiotonic steroids under physiological conditions are in the low picomolar concentration range in healthy subjects, increasing to high picomolar levels under pathophysiological conditions including chronic kidney disease and heart failure. Little is known about the physiological function of low picomolar concentrations of cardiotonic steroids. Recent studies have indicated that physiological concentrations of cardiotonic steroids acutely stimulate the activity of Na(+)/K(+) ATPase and activate an intracellular signaling pathway that regulates a variety of intracellular functions including cell growth and hypertrophy. The effects of circulating cardiotonic steroids on renal salt handling and total body sodium homeostasis are unknown. This review will focus on the role of low picomolar concentrations of cardiotonic steroids in renal Na(+)/K(+) ATPase activity, cell signaling, and blood pressure regulation.
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Affiliation(s)
- Syed Jalal Khundmiri
- Division of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USADivision of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USA
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Tomaschitz A, Piecha G, Ritz E, Meinitzer A, Haas J, Pieske B, Wiecek A, Rus-Machan J, Toplak H, März W, Verheyen N, Gaksch M, Amrein K, Kraigher-Krainer E, Fahrleitner-Pammer A, Pilz S. Marinobufagenin in essential hypertension and primary aldosteronism: a cardiotonic steroid with clinical and diagnostic implications. Clin Exp Hypertens 2014; 37:108-15. [PMID: 24785704 DOI: 10.3109/10641963.2014.913604] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The cardiotonic steroid marinobufagenin (MBG) is increasingly suggested to be responsible for some of the cardiovascular injury that has been previously attributed to aldosterone. We examined the clinical correlates of circulating MBG concentrations in hypertensive patients and tested the hypothesis that MBG serves as a reliable diagnostic tool for detecting primary aldosteronism (PA). METHODS Plasma MBG concentrations (mean: 0.51±0.25 nmol/l) were measured in the morning fasting samples in 20 patients with PA and 20 essential hypertensive (EH) controls matched for age, sex, body mass index, renal function, urinary sodium and intake of antihypertensive medication (mean age: 51.6 years; 52.2% women). RESULTS Overall, plasma MBG was directly correlated with plasma aldosterone, aldosterone to active renin ratio (AARR), diastolic blood pressure, mean carotid intima-media thickness, serum sodium, urinary protein to creatinine ratio and inversely with serum potassium levels. Plasma MBG levels were significantly higher in patients with PA compared to EH (mean: 0.68±0.12 versus 0.35±0.24 nmol/l; p<0.001). ROC analysis yielded a greater AUC for plasma MBG compared to the AARR, PAC and serum potassium levels for detecting PA. Youden's Index analyses yielded the optimal plasma MBG cut-off score for diagnosing PA at >0.49 nmol/l with specificity and sensitivity values of 0.85 and 0.95, respectively, which were higher than those at the optimum AARR cut-off at >3.32 ng/dl/µU/ml. CONCLUSIONS In a well-characterized cohort, values of plasma MBG were significantly related to clinical correlates of cardiovascular and renal disease. Plasma MBG emerged as a valuable alternative to the AARR for screening of PA.
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Konerman MC, Hummel SL. Sodium restriction in heart failure: benefit or harm? CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2014; 16:286. [PMID: 24398803 DOI: 10.1007/s11936-013-0286-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OPINION STATEMENT Current guidelines vary in the recommended amount of dietary sodium intake for heart failure (HF) patients. Observational studies and the hypertension literature support the concept that sodium restriction improves HF outcomes. In contrast, several randomized controlled trials imply that dietary sodium restriction can cause harm through hypovolemia and increased neurohormonal activation. Data from hypertensive animal models and humans suggest that dietary sodium intake may need to be individually tailored based on HF severity and the physiologic response to sodium loading. Future studies must assess interactions between sodium intake, fluid intake, and diuretics to match clinical practice and improve safety. More information is needed in multiple areas, including accurate measurement of sodium intake, implementation of dietary changes in HF patients, and establishment of biomarkers that predict response to changes in sodium intake. Additional research is urgently needed to determine the true impact of the most commonly recommended self-care strategy in HF.
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Affiliation(s)
- Matthew C Konerman
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI, USA
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Xie JX, Shapiro AP, Shapiro JI. The Trade-Off between Dietary Salt and Cardiovascular Disease; A Role for Na/K-ATPase Signaling? Front Endocrinol (Lausanne) 2014; 5:97. [PMID: 25101054 PMCID: PMC4101451 DOI: 10.3389/fendo.2014.00097] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/07/2014] [Indexed: 12/12/2022] Open
Abstract
It has been postulated for some time that endogenous digitalis-like substances, also called cardiotonic steroids (CTS), exist, and that these substances are involved in sodium handling. Within the past 20 years, these substances have been unequivocally identified and measurements of circulating and tissue concentrations have been made. More recently, it has been identified that CTS also mediate signal transduction through the Na/K-ATPase, and consequently been implicated in profibrotic pathways. This review will discuss the mechanism of CTS in renal sodium handling and a potential "trade-off" effect from their role in inducing tissue fibrosis.
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Affiliation(s)
- Joe X. Xie
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anna Pearl Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH, USA
| | - Joseph Isaac Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
- *Correspondence: Joseph Isaac Shapiro, Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, 1600 Medical Center Drive Suite 3408, Huntington, WV 25701, USA e-mail:
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Renal artery nerve distribution and density in the porcine model: biologic implications for the development of radiofrequency ablation therapies. Transl Res 2013; 162:381-9. [PMID: 23911638 DOI: 10.1016/j.trsl.2013.07.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 07/02/2013] [Accepted: 07/07/2013] [Indexed: 11/24/2022]
Abstract
Catheter-based renal artery denervation has demonstrated to be effective in decreasing blood pressure among patients with refractory hypertension. The anatomic distribution of renal artery nerves may influence the safety and efficacy profile of this procedure. We aimed to describe the anatomic distribution and density of periarterial renal nerves in the porcine model. Thirty arterial renal sections were included in the analysis by harvesting a tissue block containing the renal arteries and perirenal tissue from each animal. Each artery was divided into 3 segments (proximal, mid, and distal) and assessed for total number, size, and depth of the nerves according to the location. Nerve counts were greatest proximally (45.62% of the total nerves) and decreased gradually distally (mid, 24.58%; distal, 29.79%). The distribution in nerve size was similar across all 3 sections (∼40% of the nerves, 50-100 μm; ∼30%, 0-50 μm; ∼20%, 100-200 μm; and ∼10%, 200-500 μm). In the arterial segments ∼45% of the nerves were located within 2 mm from the arterial wall whereas ∼52% of all nerves were located within 2.5 mm from the arterial wall. Sympathetic efferent fibers outnumbered sensory afferent fibers overwhelmingly, intermixed within the nerve bundle. In the porcine model, renal artery nerves are seen more frequently in the proximal segment of the artery. Nerve size distribution appears to be homogeneous throughout the artery length. Nerve bundles progress closer to the arterial wall in the distal segments of the artery. This anatomic distribution may have implications for the future development of renal denervation therapies.
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Yan Y, Shapiro AP, Haller S, Katragadda V, Liu L, Tian J, Basrur V, Malhotra D, Xie ZJ, Abraham NG, Shapiro JI, Liu J. Involvement of reactive oxygen species in a feed-forward mechanism of Na/K-ATPase-mediated signaling transduction. J Biol Chem 2013; 288:34249-34258. [PMID: 24121502 DOI: 10.1074/jbc.m113.461020] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cardiotonic steroids (such as ouabain) signaling through Na/K-ATPase regulate sodium reabsorption in the renal proximal tubule. We report here that reactive oxygen species are required to initiate ouabain-stimulated Na/K-ATPase·c-Src signaling. Pretreatment with the antioxidant N-acetyl-L-cysteine prevented ouabain-stimulated Na/K-ATPase·c-Src signaling, protein carbonylation, redistribution of Na/K-ATPase and sodium/proton exchanger isoform 3, and inhibition of active transepithelial (22)Na(+) transport. Disruption of the Na/K-ATPase·c-Src signaling complex attenuated ouabain-stimulated protein carbonylation. Ouabain-stimulated protein carbonylation is reversed after removal of ouabain, and this reversibility is largely independent of de novo protein synthesis and degradation by either the lysosome or the proteasome pathways. Furthermore, ouabain stimulated direct carbonylation of two amino acid residues in the actuator domain of the Na/K-ATPase α1 subunit. Taken together, the data indicate that carbonylation modification of the Na/K-ATPase α1 subunit is involved in a feed-forward mechanism of regulation of ouabain-mediated renal proximal tubule Na/K-ATPase signal transduction and subsequent sodium transport.
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Affiliation(s)
- Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755; Institute of Biomedical Engineering, Yanshan University, Qinhuangdao 066004, China
| | - Anna P Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Steven Haller
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Vinai Katragadda
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Lijun Liu
- Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Jiang Tian
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614; Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109
| | - Deepak Malhotra
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Zi-Jian Xie
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614; Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Nader G Abraham
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755; Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755.
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Abstract
PURPOSE OF REVIEW Endogenous cardiotonic steroids (CTS) exert long-term effects on salt and blood pressure homeostasis. Here we discuss recent observations on mechanisms of salt sensitivity that involve endogenous ouabain and novel pathways in the brain and discuss their possible relationship to arterial and renal function in hypertension. RECENT FINDINGS Chronic elevation of brain sodium promotes sustained hypertension mediated by central endogenous ouabain and the Na(+) pump α-2 catalytic subunit. The intermediary pressor mechanism in the brain involves aldosterone biosynthesis, activation of mineralocorticoid receptors and increased epithelial sodium channel activity. In the periphery, elevated plasma CTS raise contractility and blood pressure by augmentation of sympathetic nerve responses, increasing arterial Ca(2+) signaling and blunting nitric oxide production in the renal medulla and collecting ducts. SUMMARY Endogenous ouabain in the brain appears to play a critical role in salt sensitivity and hypertension. In the periphery, the J-shaped relationship of plasma endogenous ouabain in response to short-term changes in salt balance in humans raises the possibility that endogenous ouabain contributes to the increased risk of adverse cardiovascular events associated with both low and high salt intakes.
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Age-associated increase in salt sensitivity is accompanied by a shift in the atrial natriuretic peptide modulation of the effect of marinobufagenin on renal and vascular sodium pump. J Hypertens 2012; 30:1817-26. [PMID: 22796708 DOI: 10.1097/hjh.0b013e328356399b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Marinobufagenin (MBG) promotes natriuresis via inhibition of renotubular Na/K-ATPase (NKA) and causes vasoconstriction via inhibition of vascular NKA. Atrial natriuretic peptide (ANP), via cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG)-dependent mechanism, sensitizes renal NKA to MBG but reduces MBG-induced inhibition of vascular NKA. As aging is associated with a downregulation of cGMP/PKG signaling, we hypothesized that in older rats, ANP would not potentiate renal effects of MBG and would not oppose vascular effects of MBG. METHODS In younger (3-month-old) and older (12-month-old) Sprague-Dawley rats, we compared SBP, natriuresis, activity of NKA in aorta and renal medulla, and levels of MBG and α-ANP at baseline and following acute NaCl loading (20%, 2.5 ml/kg, intraperitoneally), and studied modulation of MBG-induced NKA inhibition by α-ANP in vitro. RESULTS As compared with younger rats, NaCl-loaded older rats exhibited a greater MBG response, greater SBP elevation (25 vs. 10 mmHg, P < 0.01) and greater inhibition of NKA in aorta (39 vs. 7%, P < 0.01), 30% less natriuresis, and less inhibition of renal NKA (25 vs. 42%, P < 0.05) in the presence of comparable responses of α-ANP and cGMP. In aorta and kidney of older rats, the levels of PKG were reduced, the levels of phosphodiesterase-5 were increased compared with that in young rats, and α-ANP failed to modulate MBG-induced NKA inhibition. CONCLUSION Age-associated downregulation of cGMP/PKG-dependent signaling impairs the ability of ANP to modulate the effects of MBG on the sodium pump, which contributes to salt sensitivity.
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