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Kudryavtseva O, Lyngsø KS, Jensen BL, Dimke H. Nitric oxide, endothelium-derived hyperpolarizing factor, and smooth muscle-dependent mechanisms contribute to magnesium-dependent vascular relaxation in mouse arteries. Acta Physiol (Oxf) 2024; 240:e14096. [PMID: 38258597 DOI: 10.1111/apha.14096] [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: 06/08/2023] [Revised: 09/27/2023] [Accepted: 01/01/2024] [Indexed: 01/24/2024]
Abstract
AIM Magnesium (Mg2+ ) is a vasorelaxant. The underlying physiological mechanisms driving this vasorelaxation remain unclear. Studies were designed to test the hypothesis that multiple signaling pathways including nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) in endothelial cells as well as Ca2+ antagonization and TRPM7 channels in vascular smooth muscle cells mediate Mg2+ -dependent vessel relaxation. METHODS To uncover these mechanisms, force development was measured ex vivo in aorta rings from mice using isometric wire myography. Concentration responses to Mg2+ were studied in intact and endothelium-denuded aortas. Key findings were confirmed in second-order mesenteric resistance arteries perfused ex vivo using pressure myography. Effects of Mg2+ on NO formation were measured in Chinese Hamster Ovary (CHO) cells, isolated mesenteric vessels, and mouse urine. RESULTS Mg2+ caused a significant concentration-dependent relaxation of aorta rings. This relaxation was attenuated significantly in endothelium-denuded aortas. The endothelium-dependent portion was inhibited by NO and cGMP blockade but not by cyclooxygenase inhibition. Mg2+ stimulated local NO formation in CHO cells and isolated mesenteric vessels without changing urinary NOx levels. High extracellular Mg2+ augmented acetylcholine-induced relaxation. SKCa and IKCa channel blockers apamin and TRAM34 inhibited Mg2+ -dependent relaxation. The endothelium-independent relaxation in aorta rings was inhibited by high extracellular Ca2+ . Combined blockade of NO, SKCa , and IKCa channels significantly reduced Mg2+ -dependent dilatation in mesenteric resistance vessels. CONCLUSIONS In mouse conductance and resistance arteries Mg2+ -induced relaxation is contributed by endothelial NO formation, EDHF pathways, antagonism of Ca2+ in smooth muscle cells, and additional unidentified mechanisms.
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Affiliation(s)
- Olga Kudryavtseva
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Kristina S Lyngsø
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Boye L Jensen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
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Key Words
- Absorption
- Amphotericin B
- Antibiotics, Chemotherapeutic agents, ATP
- Calcium
- Central Nervous System, CNS
- Distribution
- Excretion
- Hypokalemia, digoxin, hypertension, insulin, intestine
- Hypomagnesemia
- Magnesium
- Metabolism
- Na+ K+/ATP-ase, enolase, pyruvate kinase
- Neuromuscular
- Potassium
- Proton pump inhibitors, Diuretics
- TRPM6 and TRPM7 channels, kidney, nephron, parathyroid hormone (PTH), antidiuretic hormone (ADH)
- TRPM6, atherosclerosis, coronary artery disease, congestive heart failure
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3
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López-Baltanás R, Encarnación Rodríguez-Ortiz M, Canalejo A, Díaz-Tocados JM, Herencia C, Leiva-Cepas F, Torres-Peña JD, Ortíz-Morales A, Muñoz-Castañeda JR, Rodríguez M, Almadén Y. Magnesium supplementation reduces inflammation in rats with induced chronic kidney disease. Eur J Clin Invest 2021; 51:e13561. [PMID: 33870500 DOI: 10.1111/eci.13561] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 03/13/2021] [Accepted: 03/29/2021] [Indexed: 01/27/2023]
Abstract
BACKGROUND Inflammation is a common feature in chronic kidney disease (CKD) that appears specifically associated with cardiovascular derangements in CKD patients. Observational studies have revealed a link between low Mg levels and inflammation. In this study, we hypothesize that Mg might have a modulatory effect on the inflammation induced under the uraemic milieu. METHODS In vivo studies were performed in a 5/6 nephrectomized rat model of CKD. Furthermore, a possible direct effect of Mg was addressed through in vitro studies with vascular smooth muscle cells (VSMCs). RESULTS Uraemic rats fed a normal (0.1%) Mg diet showed a systemic inflammatory response evidenced by the elevation in plasma of the pro-inflammatory cytokines TNF-α, IL-1β and IL-6, and GPx activity, a marker of oxidative stress. Importantly, an increased expression of these cytokines in the aortic tissue was also observed. In contrast, a dietary Mg supplementation (0.6%) greatly prevented the oxidative stress and the pro-inflammatory response. In vitro, in VSMCs cultured in a pro-inflammatory high phosphate medium, incubation with Mg 1.6 mM inhibited the increase in the production of ROS, the rise in the expression of TNF-α, IL-1β, IL-6 and IL-8 and the activation of NF-κB signalling that was observed in cells incubated with a normal (0.8 mM) Mg. CONCLUSION Mg supplementation reduced inflammation associated with CKD, exerting a direct effect on vascular cells. These findings support a possible beneficial effect of Mg supplementation along the clinical management of CKD patients.
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Affiliation(s)
- Rodrigo López-Baltanás
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Córdoba, Spain
| | - Maria Encarnación Rodríguez-Ortiz
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Córdoba, Spain.,Red Nacional de Investigación en Nefrología (REDinREN), Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio Canalejo
- Department of Integrated Sciences/Research Center RENSMA, University of Huelva, Huelva, Spain
| | - Juan M Díaz-Tocados
- Biomedical Research Institute of Lleida (IRBLleida), Vascular and Renal Translational Research Group, Arnau de Vilanova University Hospital, Lleida, Spain.,Carlos III Health Institute (ISCIII), Madrid, Spain
| | - Carmen Herencia
- Renal, Vascular and Diabetes Research Laboratory, Fundación Instituto de Investigaciones Sanitarias-Fundación Jiménez Díaz,, Universidad Autónoma de Madrid, Madrid, Spain
| | - Fernando Leiva-Cepas
- UGC de Anatomía Patología del Hospital Universitario Reina Sofía de Córdoba, Córdoba, Spain.,Departamento de Ciencias Morfológicas y Ciencias Sociosanitarias, Facultad de Medicina y Enfermería, Universidad de Córdoba, Córdoba, Spain
| | - José D Torres-Peña
- Lipid and Atherosclerosis Unit, Department of Internal Medicine, IMIBIC/Reina Sofia University Hospital/University of Cordoba, Córdoba, Spain.,CIBER Fisiopatologia Obesidad y Nutricion (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Ortíz-Morales
- Lipid and Atherosclerosis Unit, Department of Internal Medicine, IMIBIC/Reina Sofia University Hospital/University of Cordoba, Córdoba, Spain.,CIBER Fisiopatologia Obesidad y Nutricion (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Juan Rafael Muñoz-Castañeda
- Red Nacional de Investigación en Nefrología (REDinREN), Instituto de Salud Carlos III, Madrid, Spain.,Instituto Maimonides de Investigacion Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Unidad de Gestión Clinica Nefrología, Córdoba, Spain
| | - Mariano Rodríguez
- Red Nacional de Investigación en Nefrología (REDinREN), Instituto de Salud Carlos III, Madrid, Spain.,Instituto Maimonides de Investigacion Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Unidad de Gestión Clinica Nefrología, Córdoba, Spain
| | - Yolanda Almadén
- CIBER Fisiopatologia Obesidad y Nutricion (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain.,Unidad de Gestión Clinica Medicina Interna, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Córdoba, Spain
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4
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Magnesium and Hypertension in Old Age. Nutrients 2020; 13:nu13010139. [PMID: 33396570 PMCID: PMC7823889 DOI: 10.3390/nu13010139] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/27/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022] Open
Abstract
Hypertension is a complex condition in which various actors and mechanisms combine, resulting in cardiovascular and cerebrovascular complications that today represent the most frequent causes of mortality, morbidity, disability, and health expenses worldwide. In the last decades, there has been an exceptional amount of experimental, epidemiological, and clinical studies confirming a close relationship between magnesium deficit and high blood pressure. Multiple mechanisms may help to explain the bulk of evidence supporting a protective effect of magnesium against hypertension and its complications. Hypertension increases sharply with advancing age, hence older persons are those most affected by its negative consequences. They are also more frequently at risk of magnesium deficiency by multiple mechanisms, which may, at least in part, explain the higher frequency of hypertension and its long-term complications. The evidence for a favorable effect of magnesium on hypertension risk emphasizes the importance of broadly encouraging the intake of foods such as vegetables, nuts, whole cereals and legumes, optimal dietary sources of magnesium, avoiding processed food, which are very poor in magnesium and other fundamental nutrients, in order to prevent hypertension. In some cases, when diet is not enough to maintain an adequate magnesium status, magnesium supplementation may be of benefit and has been shown to be well tolerated.
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Kazemi-Darabadi S, Akbari G. Evaluation of magnesium sulfate effects on fetus development in experimentally induced surgical fetal growth restriction in rat. J Matern Fetal Neonatal Med 2018; 33:2459-2465. [PMID: 30486703 DOI: 10.1080/14767058.2018.1554048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Objective: The objective of this study was to evaluate the effect of magnesium sulfate in the prevention of fetal growth restriction due to the impaired uterine blood supply in the rat model.Methods: A total number of 24 female rats were used in this study. They were mated overnight and randomly divided into control and treatment groups. After anesthesia and incising abdominal midline in day 17 of gestation, the uterine artery was occluded by an atraumatic clamp for 60 min. The rats of the control group received normal saline after surgery and the rats of treatment group received magnesium sulfate subcutaneously. The laparotomy was repeated on day 21 of gestation, and the number of alive and dead fetuses was counted in each horn. The viability of fetuses was evaluated. The weight of the placenta and fetuses and the distance between the head and tail as well as back to the abdomen of the fetuses were also measured. Samples of the amniotic fluid (AF) were collected during both surgeries for biochemical analyses of the glucose, urea, lactate, and pyruvate levels by an AutoAnalyzer.Results: Among the total fetuses in ischemic horn, only 50% survived in the control group. Dead fetuses had less body consistency and had a dark color. In contrary, only 7.6% of the fetuses in the treatment group were absorbed and 92.4% were completely healthy and developed. Parameters related to placenta weight, fetus weight, fetus length, and fetus width had significant differences and those of the treatment group were higher. Glucose and lactate levels of the AF in the treatment group were significantly lower and urea level was significantly higher than the control group in day 21 of gestation. The changes in pyruvate levels were not significant.Conclusion: In conclusion, magnesium sulfate may counteract with the effects of temporary uterine ischemia in pregnant rats and prevent intrauterine growth restriction.
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Affiliation(s)
- Siamak Kazemi-Darabadi
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
| | - Ghasem Akbari
- Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
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Li PC, Pan CH, Sheu MJ, Wu CC, Ma WF, Wu CH. Deep sea water prevents balloon angioplasty-induced hyperplasia through MMP-2: an in vitro and in vivo study. PLoS One 2014; 9:e96927. [PMID: 24824358 PMCID: PMC4019650 DOI: 10.1371/journal.pone.0096927] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 04/13/2014] [Indexed: 11/21/2022] Open
Abstract
Major facts about the development of restenosis include vascular smooth muscle cells (VSMCs) proliferation and migration. A previous study showed that in vitro treatment with magnesium chloride has the potential to affect the proliferation and migration of VSMCs. Magnesium is the major element in deep sea water (DSW) and is a biologically active mineral. It is unclear whether DSW intake can prevent abnormal proliferation and migration of VSMCs as well as balloon angioplasty-induced neointimal hyperplasia. Thus, we attempted to evaluate the anti-restenotic effects of DSW and its possible molecular mechanisms. Several concentrations of DSW, based on the dietary recommendations (RDA) for magnesium, were applied to a model of balloon angioplasty in SD rats. The results showed that DSW intake markedly increased magnesium content within the vascular wall and reduced the development of neointimal hyperplasia. The immunohistochemical analysis also showed that the expression of proteins associated with cell proliferation and migration were decreased in the balloon angioplasty groups with DSW supplement. Furthermore, in vitro treatment with DSW has a dose-dependent inhibitory effect on serum-stimulated proliferation and migration of VSMCs, whose effects might be mediated by modulation of mitogen-activated protein kinase (MAPK) signaling and of the activity of matrix metalloproteinase-2 (MMP-2). Our study suggested that DSW intake can help prevent neointimal hyperplasia (or restenosis), whose effects may be partially regulated by magnesium and other minerals.
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Affiliation(s)
- Pei-Chuan Li
- School of Pharmacy, China Medical University, Taichung, Taiwan
| | - Chun-Hsu Pan
- College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Ming-Jyh Sheu
- School of Pharmacy, China Medical University, Taichung, Taiwan
- * E-mail: (CHW); (MJS)
| | - Chin-Ching Wu
- Department of Public Health, China Medical University, Taichung, Taiwan
| | - Wei-Fen Ma
- School of Nursing, China Medical University, Taichung, Taiwan
| | - Chieh-Hsi Wu
- School of Pharmacy, China Medical University, Taichung, Taiwan
- College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
- * E-mail: (CHW); (MJS)
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7
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Cunha AR, Medeiros F, Umbelino B, Oigman W, Touyz RM, Neves MF. Altered vascular structure and wave reflection in hypertensive women with low magnesium levels. ACTA ACUST UNITED AC 2013; 7:344-52. [DOI: 10.1016/j.jash.2013.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 04/03/2013] [Accepted: 04/21/2013] [Indexed: 11/15/2022]
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8
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Magnesium and vascular changes in hypertension. Int J Hypertens 2012; 2012:754250. [PMID: 22518291 PMCID: PMC3299255 DOI: 10.1155/2012/754250] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 12/19/2011] [Indexed: 12/15/2022] Open
Abstract
Many factors have been implicated in the pathogenesis of hypertension, including changes in intracellular concentrations of calcium, sodium, potassium, and magnesium. There is a significant inverse correlation between serum magnesium and incidence of cardiovascular diseases. Magnesium is a mineral with important functions in the body such as antiarrhythmic effect, actions in vascular tone, contractility, glucose metabolism, and insulin homeostasis. In addition, lower concentrations of magnesium are associated with oxidative stress, proinflammatory state, endothelial dysfunction, platelet aggregation, insulin resistance, and hyperglycemia. The conflicting results of studies evaluating the effects of magnesium supplements on blood pressure and other cardiovascular outcomes indicate that the action of magnesium in the vascular system is present but not yet established. Therefore, this mineral supplementation is not indicated as part of antihypertensive treatment, and further studies are needed to better clarify the role of magnesium in the prevention and treatment of cardiovascular diseases.
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9
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Paravicini TM, Yogi A, Mazur A, Touyz RM. Dysregulation of vascular TRPM7 and annexin-1 is associated with endothelial dysfunction in inherited hypomagnesemia. Hypertension 2008; 53:423-9. [PMID: 19103997 DOI: 10.1161/hypertensionaha.108.124651] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inadequate magnesium intake and hypomagnesemia may contribute to chronic diseases, such as hypertension. The novel magnesium transporter TRPM7 is a critical regulator of magnesium homeostasis in vascular cells, but its role in pathophysiology is unclear. In a model of hypomagnesemia, we examined microvascular structure and function, TRPM7 expression, and vascular inflammatory status using inbred mice selected for normal-high intracellular magnesium levels or low intracellular magnesium levels (MgLs). Blood pressure was significantly increased in MgLs compared with normal-high intracellular magnesium levels. Pressurized myography of mesenteric resistance arteries showed that MgLs had significantly impaired endothelial function together with decreased plasma nitrate levels and endothelial NO synthase expression when compared with normal-high intracellular magnesium levels. Significant differences in vascular structure were also evident in both mesenteric arteries and aortas from MgLs. Aortas from MgLs had increased medial cross-sectional areas, whereas mesenteric arteries from MgLs had increased lumen diameters with increased medial cross-sectional areas, indicating outward hypertrophic remodeling. Expression of the magnesium transporter TRPM7 was significantly elevated in the vasculature of MgLs, whereas expression of a TRPM7 downstream target, the anti-inflammatory molecule annexin-1, was reduced. MgLs had increased expression of vascular cell adhesion molecule-1 and plasminogen activator inhibitor-1, indicating vascular inflammation. Taken together, these data demonstrate that the inherited magnesium status of MgLs and normal-high intracellular magnesium levels mice affects magnesium transporter expression, endothelial function, vascular structure, and inflammation. Our findings suggest a potential regulatory role for TRPM7 signaling in the maintenance of vascular integrity. Alterations in magnesium status and/or TRPM7 signaling may contribute to vascular injury in conditions associated with hypomagnesemia.
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Affiliation(s)
- Tamara M Paravicini
- Kidney Research Centre, University of Ottawa/Ottawa Health Research Institute, 451 Smyth Rd, Ottawa, ON, KIH 8M5 Canada
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10
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Touyz RM. Transient receptor potential melastatin 6 and 7 channels, magnesium transport, and vascular biology: implications in hypertension. Am J Physiol Heart Circ Physiol 2008; 294:H1103-18. [PMID: 18192217 DOI: 10.1152/ajpheart.00903.2007] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Magnesium, an essential intracellular cation, is critically involved in many biochemical reactions involved in the regulation of vascular tone and integrity. Decreased magnesium concentration has been implicated in altered vascular reactivity, endothelial dysfunction, vascular inflammation, and structural remodeling, processes important in vascular changes and target organ damage associated with hypertension. Until recently, very little was known about mechanisms regulating cellular magnesium homeostasis, and processes controlling transmembrane magnesium transport had been demonstrated only at the functional level. Two cation channels of the transient receptor potential melastatin (TRPM) cation channel family have now been identified as magnesium transporters, TRPM6 and TRPM7. These unique proteins, termed chanzymes because they possess a channel and a kinase domain, are differentially expressed, with TRPM6 being found primarily in epithelial cells and TRPM7 occurring ubiquitously. Vascular TRPM7 is modulated by vasoactive agents, pressure, stretch, and osmotic changes and may be a novel mechanotransducer. In addition to its magnesium transporter function, TRPM7 has been implicated as a signaling kinase involved in vascular smooth muscle cell growth, apoptosis, adhesion, contraction, cytoskeletal organization, and migration, important processes involved in vascular remodeling associated with hypertension and other vascular diseases. Emerging evidence suggests that vascular TRPM7 function may be altered in hypertension. This review discusses the importance of magnesium in vascular biology and implications in hypertension and highlights the transport systems, particularly TRPM6 and TRPM7, which may play a role in the control of vascular magnesium homeostasis. Since the recent identification and characterization of Mg2+-selective transporters, there has been enormous interest in the field. However, there is still a paucity of information, and much research is needed to clarify the exact mechanisms of magnesium regulation in the cardiovascular system and the implications of aberrant transmembrane magnesium transport in the pathogenesis of hypertension and other vascular diseases.
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Affiliation(s)
- Rhian M Touyz
- Kidney Research Center, Ottawa Heallth Research Institute, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5.
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Yang HT, Chou HJ, Han BC, Huang SY. Lifelong inorganic arsenic compounds consumption affected blood pressure in rats. Food Chem Toxicol 2007; 45:2479-87. [PMID: 17688991 DOI: 10.1016/j.fct.2007.05.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 04/16/2007] [Accepted: 05/23/2007] [Indexed: 11/24/2022]
Abstract
Chronic arsenic exposure is a known risk factor for cardiovascular disease and has a strong correlation with hypertension. Oxidative stress may be one of the major contributors to arsenic-induced hypertension. To investigate the antioxidative and CYP systems through which inorganic arsenic compounds may contribute to blood pressure elevation in rats, we administered 50ppm arsenic (as arsenite and arsenate) in drinking water to Wistar rats for 200 successive days. Systolic blood pressure was determined every 20 days, and blood samples and tissues were collected at each time point for biological analysis. Compared to the control group, weight gain in the arsenic-exposed animals was slightly but significantly lower, whereas the relative weights of the various tissues was higher. Blood pressure was elevated until day 80 in both arsenic groups followed by a time-dependent change in the antioxidative enzyme system. The hypertensive effect remained until day 200 for arsenite when the change by arsenate was minimized. Patterns of antioxidative enzyme change differed between arsenite and arsenate. However, the most common marker of hypertension, the angiotensin-converting enzyme, showed no significant change in either arsenic group. CYP4A was highly expressed in both arsenic groups, particularly in the arsenite group. These results indicate that low but chronic arsenic exposure might cause elevated blood pressure and antioxidative interference. Furthermore, CYP4A might be more important than ACE in contributing to arsenic-induced hypertension.
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Affiliation(s)
- Hui-Ting Yang
- School of Pharmaceutical Science, Taipei Medical University, Taipei 110, Taiwan
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Karaszewski B, Kozera G, Dorosz A, Łukasiak J, Szczyrba S, Łysiak-Szydłowska W, Nyka WM. High magnesium or potassium hair accumulation is not associated with ischemic stroke risk reduction: A pilot study. Clin Neurol Neurosurg 2007; 109:676-9. [PMID: 17624662 DOI: 10.1016/j.clineuro.2007.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 05/25/2007] [Accepted: 05/26/2007] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Various studies suggest that deficiency of magnesium and potassium may be associated with increased risk of ischemic stroke. However, single time-point serum measurements may not be suitable for assessing long-term tissue levels. PATIENTS AND METHODS We investigated Mg and K levels in hair of patients with acute ischemic stroke. The elements hair accumulation analysis might provide historical information on their concentrations over a longer period of time and probably reflects the corresponding nutritional condition. The concentrations of Mg and K in hair of 48 men with acute ischemic stroke and a control group were measured using spectroscopic methods. RESULTS The mean Mg and K concentrations in hair of patients were significantly higher than in the controls. CONCLUSIONS This analysis does not seem to confirm the results of the previous studies suggesting that Mg or K high levels (or their diet supplementation) might protect humans against ischemic stroke.
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Affiliation(s)
- Bartosz Karaszewski
- Department of Neurology of Adults, Medical University of Gdansk, Ul. Debinki 7, 80-211 Gdansk, Poland.
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Adrian M, Laurant P, Berthelot A. EFFECT OF MAGNESIUM ON MECHANICAL PROPERTIES OF PRESSURIZED MESENTERIC SMALL ARTERIES FROM OLD AND ADULT RATS. Clin Exp Pharmacol Physiol 2004; 31:306-13. [PMID: 15191403 DOI: 10.1111/j.1440-1681.2004.03992.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of the present study was to determine the effects of magnesium (Mg) on the mechanical properties of resistance arteries in adult and old rats. Studies were performed in adult (17 weeks) and old (104 weeks) male Wistar rats. The vasodilatory response and the passive mechanical properties of the wall of isolated perfused and pressurized arterial segments of mesenteric small arteries were investigated after Mg and verapamil application, both known for their calcium antagonistic properties. Mesenteric resistance arteries from old rats exhibited an outward hypertrophic remodelling, with enlargment of the lumen, thickening of the media and enlarged media cross-sectional area. The vasodilatory response induced by the application of increasing extracellular concentrations of Mg and verapamil was significantly smaller in preconstricted mesenteric arteries of old rats than in those of adult rats. Incremental distensibility in response to increasing intravascular pressures did not change. However, the stress-strain curve was shifted to the left in pressurized mesenteric arteries from old rats, indicating arterial wall stiffness. Verapamil (3 micro mol/L) did not modify the stress-strain curves in either adult or aged rats. However, Mg (4.8 mmol/L) significantly shifted the curve to the right in mesenteric arteries from adult rats and, to a greater degree, in those from old rats. Although Mg-induced vasodilatation is impaired in aged rats, increased Mg concentration improved the mechanics of pressurized mesenteric resistance arteries. The fact that Mg decreases arterial stiffness in arteries from old rats suggests that Mg has a beneficial effect on age-related changes to the vascular wall.
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Affiliation(s)
- Mark Adrian
- Laboratoire Physiologie Pharmacologie et Nutrition Préventive Expérimentale, Besançon, France
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Amighi J, Sabeti S, Schlager O, Mlekusch W, Exner M, Lalouschek W, Ahmadi R, Minar E, Schillinger M. Low Serum Magnesium Predicts Neurological Events in Patients With Advanced Atherosclerosis. Stroke 2004; 35:22-7. [PMID: 14657448 DOI: 10.1161/01.str.0000105928.95124.1f] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Magnesium (Mg) deficiency is thought to be a risk factor for cerebrovascular atherosclerosis and complications. We investigated the prognostic impact of Mg serum levels with respect to the occurrence of neurological events in patients with advanced atherosclerosis.
Methods—
We prospectively studied 323 patients with symptomatic peripheral artery disease and intermittent claudication (197 men; median age, 68 years). Serum Mg was determined, and patients were followed for a median of 20 months (interquartile range, 12 to 25 months) for the occurrence of neurological events, defined as ischemic stroke and/or carotid revascularization (carotid endarterectomy or carotid stenting). Multivariate Cox proportional hazards analysis was applied to assess the association of serum Mg (in tertiles) and neurological events.
Results—
Neurological events occurred in 35 patients (11%) (15 patients with stroke, 13 with carotid revascularization, and 7 with stroke and subsequent revascularization). Compared with patients in the highest tertile of Mg serum levels (>0.84 mmol/L), patients with Mg serum values <0.76 mmol/L (lowest tertile) exhibited a 3.29-fold increased adjusted risk (95% CI, 1.34 to 7.90; P=0.009) for neurological events, but patients with Mg serum values of 0.76 mmol/L to 0.84 mmol/L (middle tertile) had no increased risk (adjusted hazard ratio, 1.10; 95% CI, 0.35 to 3.33; P=0.88). Mg serum levels were not associated with all-cause mortality (P=0.87) or coronary events (P=0.67) during follow-up.
Conclusions—
Low Mg serum levels indicate an increased risk for neurological events in patients with symptomatic peripheral artery disease, favoring Mg substitution therapy in those patients with advanced atherosclerosis.
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Affiliation(s)
- Jasmin Amighi
- Department of Angiology, Vienna General Hospital, Medical School, Vienna, Austria
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Touyz RM, Yao G. Inhibitors of Na+/Mg2+ exchange activity attenuate the development of hypertension in angiotensin II-induced hypertensive rats. J Hypertens 2003; 21:337-44. [PMID: 12569264 DOI: 10.1097/00004872-200302000-00025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To investigate whether imipramine and quinidine, inhibitors of the Na /Mg exchanger, influence development of hypertension in rats infused with angiotensin (Ang) II. METHODS Sprague-Dawley rats were divided into six groups: (1) control (vehicle); (2) Ang II (150 ng/kg per min subcutaneously); (3) imipramine alone (5 mg/kg per day in drinking water); (4) quinidine alone (5 mg/kg per day in drinking water); (5) Ang II plus imipramine; (6) Ang II plus quinidine. Rats were studied for 3 weeks. To verify that Ang II directly influences Na -dependent Mg exchange, in-vitro studies were performed in vascular smooth muscle cells (VSMCs) derived from mesenteric arteries. RESULTS Ang II increased systolic blood pressure (SBP) in all groups. The magnitude of the increase was lower ( 0.01) in Ang II groups treated with imipramine (151 +/- 7.4 mmHg) or quinidine (163 +/- 4 mmHg) than in the Ang II only group (205 +/- 4 mmHg). Neither imipramine nor quinidine influenced SBP in vehicle-treated rats. Plasma concentrations of Mg and K were decreased in Ang II rats compared with controls (P < 0.05). Platelet intracellular free Mg concentration was reduced and platelet intracellular free Na concentration was increased in the Ang II group compared with control and treated groups (P < 0.01). These effects were normalized by imipramine and quinidine. Ang II stimulated Na -dependent Mg transport in VSMCs. These actions were abrogated by imipramine and quinidine and in Na -free conditions. CONCLUSIONS Our data demonstrate that inhibitors of Na -dependent Mg transport attenuate development of hypertension in rats infused with Ang II. These findings suggest a possible role for Na /Mg exchange activity in the pathogenesis of Ang II-dependent hypertension.
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Affiliation(s)
- Rhian M Touyz
- Multidisciplinary Group on Hypertension, Clinical Research Institute of Montrel, Quebec, Canada.
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