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Nakatsukasa T, Ishizu T, Ouchi M, Murakoshi N, Sato K, Yamamoto M, Kawanishi K, Seo Y, Ieda M. Sodium Glucose Co-Transporter 2 Inhibitors Improve Renal Congestion and Left Ventricular Fibrosis in Rats With Hypertensive Heart Failure. Circ J 2022; 86:2029-2039. [PMID: 35944977 DOI: 10.1253/circj.cj-22-0105] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Elevated central venous pressure (CVP) in heart failure causes renal congestion, which deteriorates prognosis. Sodium glucose co-transporter 2 inhibitor (SGLT2-i) improves kidney function and heart failure prognosis; however, it is unknown whether they affect renal congestion. This study investigated the effect of SGLT2-i on the kidney and left ventricle using model rats with hypertensive heart failure.Methods and Results: Eight rats were fed a 0.3% low-salt diet (n=7), and 24 rats were fed an 8% high-salt diet, and they were divided into 3 groups of untreated (n=6), SGLT2-i (canagliflozin; n=6), and loop diuretic (furosemide; n=5) groups after 11 weeks of age. At 18 weeks of age, CVP and renal intramedullary pressure (RMP) were monitored directly by catheterization. We performed contrast-enhanced ultrasonography to evaluate intrarenal perfusion. In all high-salt fed groups, systolic blood pressure was elevated (P=0.287). The left ventricular ejection fraction did not differ among high-salt groups. Although CVP decreased in both the furosemide (P=0.032) and the canagliflozin groups (P=0.030), RMP reduction (P=0.003) and preserved renal medulla perfusion were only observed in the canagliflozin group (P=0.001). Histological analysis showed less cast formation in the intrarenal tubule (P=0.032), left ventricle fibrosis (P<0.001), and myocyte thickness (P<0.001) in the canagliflozin group than in the control group. CONCLUSIONS These results suggest that SGLT2-i causes renal decongestion and prevents left ventricular hypertrophy, fibrosis, and dysfunction.
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Affiliation(s)
- Tomofumi Nakatsukasa
- Department of Cardiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Tomoko Ishizu
- Department of Cardiology, Faculty of Medicine, University of Tsukuba
| | - Masumi Ouchi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | | | - Kimi Sato
- Department of Cardiology, Faculty of Medicine, University of Tsukuba
| | | | - Kunio Kawanishi
- Department of Experimental Pathology, Faculty of Medicine, University of Tsukuba
| | - Yoshihiro Seo
- Department of Cardiology, Faculty of Medicine, Nagoya City University Graduate School of Medical Sciences
| | - Masaki Ieda
- Department of Cardiology, Faculty of Medicine, University of Tsukuba
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Amegandjin CA, Jammow W, Laforest S, Riad M, Baharnoori M, Badeaux F, DesGroseillers L, Murai KK, Pasquale EB, Drolet G, Doucet G. Regional expression and ultrastructural localization of EphA7 in the hippocampus and cerebellum of adult rat. J Comp Neurol 2016; 524:2462-78. [PMID: 26780036 DOI: 10.1002/cne.23962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 12/18/2015] [Accepted: 01/04/2016] [Indexed: 11/06/2022]
Abstract
EphA7 is expressed in the adult central nervous system (CNS), where its roles are yet poorly defined. We mapped its distribution using in situ hybridization (ISH) and immunohistochemistry (IHC) combined with light (LM) and electron microscopy (EM) in adult rat and mouse brain. The strongest ISH signal was in the hippocampal pyramidal and granule cell layers. Moderate levels were detected in habenula, striatum, amygdala, the cingulate, piriform and entorhinal cortex, and in cerebellum, notably the Purkinje cell layer. The IHC signal distribution was consistent with ISH results, with transport of the protein to processes, as exemplified in the hippocampal neuropil layers and weakly stained pyramidal cell layers. In contrast, in the cerebellum, the Purkinje cell bodies were the most strongly immunolabeled elements. EM localized the cell surface-expression of EphA7 essentially in postsynaptic densities (PSDs) of dendritic spines and shafts, and on some astrocytic leaflets, in both hippocampus and cerebellum. Perikaryal and dendritic labeling was mostly intracellular, associated with the synthetic and trafficking machineries. Immunopositive vesicles were also observed in axons and axon terminals. Quantitative analysis in EM showed significant differences in the frequency of labeled elements between regions. Notably, labeled dendrites were ∼3-5 times less frequent in cerebellum than in hippocampus, but they were individually endowed with ∼10-40 times higher frequencies of PSDs, on their shafts and spines. The cell surface localization of EphA7, being preferentially in PSDs, and in perisynaptic astrocytic leaflets, provides morphologic evidence that EphA7 plays key roles in adult CNS synaptic maintenance, plasticity, or function. J. Comp. Neurol. 524:2462-2478, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Clara A Amegandjin
- Département de neurosciences and Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC, Canada
| | - Wafaa Jammow
- Département de neurosciences and Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC, Canada
| | - Sylvie Laforest
- Centre hospitalier de l'Université Laval (CHUL), Québec, QC, Canada
| | - Mustapha Riad
- Département de neurosciences and Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC, Canada
| | - Moogeh Baharnoori
- Département de neurosciences and Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC, Canada
| | - Frédérique Badeaux
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Luc DesGroseillers
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Keith K Murai
- Department of Neurology and Neurosurgery, McGill University, and Center for Research in Neuroscience, Montréal, QC, Canada
| | - Elena B Pasquale
- Sanford-Burnham Medical Research Institute, La Jolla, California, and Pathology Department, University of California, San Diego, La Jolla, California, USA
| | - Guy Drolet
- Centre hospitalier de l'Université Laval (CHUL), Québec, QC, Canada
| | - Guy Doucet
- Département de neurosciences and Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC, Canada
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Berret E, Smith PY, Henry M, Soulet D, Hébert SS, Toth K, Mouginot D, Drolet G. Extracellular Na(+) levels regulate formation and activity of the NaX/alpha1-Na(+)/K(+)-ATPase complex in neuronal cells. Front Cell Neurosci 2014; 8:413. [PMID: 25538563 PMCID: PMC4255601 DOI: 10.3389/fncel.2014.00413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 11/13/2014] [Indexed: 11/23/2022] Open
Abstract
MnPO neurons play a critical role in hydromineral homeostasis regulation by acting as sensors of extracellular sodium concentration ([Na+]out). The mechanism underlying Na+-sensing involves Na+-flow through the NaX channel, directly regulated by the Na+/K+-ATPase α1-isoform which controls Na+-influx by modulating channel permeability. Together, these two partners form a complex involved in the regulation of intracellular sodium ([Na+]in). Here we aim to determine whether environmental changes in Na+ could actively modulate the NaX/Na+/K+-ATPase complex activity. We investigated the complex activity using patch-clamp recordings from rat MnPO neurons and Neuro2a cells. When the rats were fed with a high-salt-diet, or the [Na+] in the culture medium was increased, the activity of the complex was up-regulated. In contrast, drop in environmental [Na+] decreased the activity of the complex. Interestingly under hypernatremic condition, the colocalization rate and protein level of both partners were up-regulated. Under hyponatremic condition, only NaX protein expression was increased and the level of NaX/Na+/K+-ATPase remained unaltered. This unbalance between NaX and Na+/K+-ATPase pump proportion would induce a bigger portion of Na+/K+-ATPase-control-free NaX channel. Thus, we suggest that hypernatremic environment increases NaX/Na+/K+-ATPase α1-isoform activity by increasing the number of both partners and their colocalization rate, whereas hyponatremic environment down-regulates complex activity via a decrease in the relative number of NaX channels controlled by the pump.
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Affiliation(s)
| | - Pascal Y Smith
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada
| | - Mélaine Henry
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada
| | - Denis Soulet
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada ; Faculté de Médecine, Département de Psychiatrie et Neurosciences, Université Laval QC, Canada
| | - Sébastien S Hébert
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada ; Faculté de Médecine, Département de Psychiatrie et Neurosciences, Université Laval QC, Canada
| | - Katalin Toth
- Faculté de Médecine, Département de Psychiatrie et Neurosciences, Université Laval QC, Canada ; Institut Universitaire de Santé Mentale de Québec, Université Laval QC, Canada
| | - Didier Mouginot
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada ; Institut Universitaire de Santé Mentale de Québec, Université Laval QC, Canada
| | - Guy Drolet
- Centre de Recherche du CHU de Québec, Axe Neurosciences QC, Canada ; Faculté de Médecine, Département de Psychiatrie et Neurosciences, Université Laval QC, Canada
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Essential hypertension: an approach to its etiology and neurogenic pathophysiology. Int J Hypertens 2013; 2013:547809. [PMID: 24386559 PMCID: PMC3872229 DOI: 10.1155/2013/547809] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 11/06/2013] [Indexed: 12/24/2022] Open
Abstract
Essential hypertension, a rise in blood pressure of undetermined cause, includes 90% of all hypertensive cases and is a highly important public health challenge that remains, however, a major modifiable cause of morbidity and mortality. This review emphasizes that, from an evolutionary point of view, we are adapted to ingest and excrete <1 g of sodium (2.5 g of salt) per day and that essential hypertension develops when the kidneys become unable to excrete the amount of sodium ingested, unless blood pressure is increased. The renal-mean arterial pressure set-point model is briefly described to explain that a shift of the pressure natriuresis relationship toward abnormally high pressure levels is a pathophysiological characteristic of essential hypertension. Evidence indicating that this anomaly in the pressure natriuresis relationship arises from a sympathetic nervous system dysfunction is briefly formulated, and the most widely accepted pathophysiologic proposal to explain the development of this sympathetic dysfunction is described, with commentaries about novel action mechanisms of some drugs currently used in essential hypertension treatment.
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Sakae R, Ishikawa A, Niso T, Komori Y, Aiba T, Kawasaki H, Kurosaki Y. Decreased Lithium Disposition to Cerebrospinal Fluid in Rats with Glycerol-induced Acute Renal Failure. Pharm Res 2008; 25:2243-9. [DOI: 10.1007/s11095-008-9612-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Accepted: 04/25/2008] [Indexed: 10/21/2022]
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Henry M, Drolet G, Mouginot D. Postsynaptic mu-opioid receptor response in the median preoptic nucleus is altered by a systemic sodium challenge in rats. Eur J Neurosci 2008; 27:1197-209. [PMID: 18364037 DOI: 10.1111/j.1460-9568.2008.06087.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The median preoptic nucleus (MnPO) is an integrator site for the chemosensory and neural signals induced by a perturbation in the hydromineral balance, and it is highly involved in controlling fluid and electrolyte ingestion. Here, we hypothesize that opioid peptides, previously recognized to control ingestive behaviors, may regulate the excitability of MnPO neurons and that this regulatory action may depend on the natriuric (Na(+)) status of body fluid compartments. Our results show that activation of mu-, but not delta-, opioid receptors (OR) triggered a membrane hyperpolarization by recruiting a G-protein-regulated inward-rectifier K(+) (GIRK) conductance in 41% of the neurons tested. Interestingly, 24 h Na(+) depletion strengthened this opioid-mediated control of neuronal excitability. In Na(+)-depleted animals, the neuronal population displaying the mu-OR-induced hyperpolarization expanded to 60% (Z-test, P = 0.012), whereas Na(+) repletion restored this population to the control level (39%; Z-test, P = 0.037). Among the neurons displaying mu-OR-induced hyperpolarization, Na(+) depletion specifically increased the neuronal population responsive to variation in ambient Na(+) (from 27% to 43%; Z-test, P = 0.029). In contrast, Na(+) repletion dramatically reduced the population that was unresponsive to Na(+) (from 17% to 3%; Z-test, P = 0.031). Neither the basic properties of the neurons nor the characteristics of the mu-OR-induced response were altered by the body Na(+) challenge. Our results indicate that an episode of Na(+) depletion/Na(+) repletion modifies the organization of the opioid-sensitive network of the MnPO. Such network plasticity might be related to the avid salt ingestion triggered by repeated Na(+) depletion.
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Affiliation(s)
- Mélaine Henry
- Centre de recherche du CHUL (CHUQ), Unité de Neurosciences et Université Laval, Québec, QC, Canada G1V 4G2
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