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Sepulchro Mulher LCC, Simões RP, Rossi KA, Schereider IRG, Silva Nascimento CLD, Ávila RA, Padilha AS. In vitro cadmium exposure induces structural damage and endothelial dysfunction in female rat aorta. Biometals 2023; 36:1405-1420. [PMID: 37651061 DOI: 10.1007/s10534-023-00526-5] [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: 06/09/2023] [Accepted: 07/31/2023] [Indexed: 09/01/2023]
Abstract
Cadmium is a heavy metal that is widespread in the environment and has been described as a metalloestrogen and a cardiovascular risk factor. Experimental studies conducted in male animals have shown that cadmium exposure induces vascular dysfunction, which could lead to vasculopathies caused by this metal. However, it is necessary to investigate the vascular effects of cadmium in female rats to understand its potential sex-dependent impact on the cardiovascular system. While its effects on male rats have been studied, cadmium may act differently in females due to its potential as a metalloestrogen. In vitro studies conducted in a controlled environment allow for a direct assessment of cadmium's impact on vascular function, and the use of female rats ensures that sex-dependent effects are evaluated. Therefore, the aim of this study was to investigate the in vitro effects of Cadmium Chloride (CdCl2, 5 µM) exposure on vascular reactivity in the isolated aorta of female Wistar rats. Exposure to CdCl2 damaged the architecture of the vascular endothelium. CdCl2 incubation increased the production and release of O2•-, reduced the participation of potassium (K+) channels, and increased the participation of the angiotensin II pathway in response to phenylephrine. Moreover, estrogen receptors alpha (Erα) modulated vascular reactivity to phenylephrine in the presence of cadmium, supporting the hypothesis that cadmium could act as a metalloestrogen. Our results demonstrated that in vitro cadmium exposure induces damage to endothelial architecture and an increase in oxidative stress in the isolated aorta of female rats, which could precipitate vasculopathies. Graphical Abstract. Own source from Canva and Servier Medical Art servers.
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Affiliation(s)
- Lorraine Christiny Costa Sepulchro Mulher
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Rakel Passos Simões
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Karoline Alves Rossi
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Ingridy Reinholz Grafites Schereider
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Camilla Lóren da Silva Nascimento
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Renata Andrade Ávila
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil
| | - Alessandra Simão Padilha
- Physiological Sciences Post-Graduation Program, CCS/UFES, Federal University of Espírito Santo, Av. Marechal Campos, 1468, 26 Maruípe, Vitoria, ES, 29043-900, Brazil.
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Schereider IRG, Vassallo DV, Simões MR. Chronic mercury exposure induces oxidative stress in female rats by endothelial nitric oxide synthase uncoupling and cyclooxygenase-2 activation, without affecting oestrogen receptor function. Basic Clin Pharmacol Toxicol 2021; 129:470-485. [PMID: 34491608 DOI: 10.1111/bcpt.13655] [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: 12/02/2020] [Revised: 08/04/2021] [Accepted: 09/02/2021] [Indexed: 11/29/2022]
Abstract
Mercury has been shown to be a significant health risk factor and is positively associated with cardiovascular diseases. Evidence reveals that men are more likely to develop cardiovascular diseases than women during reproductive age. However, the effects of mercury in females remain poorly investigated, despite the finding that female hormones demonstrate a cardioprotective role. In the present study, we evaluated whether chronic mercury chloride exposure could alter blood pressure and vascular function of the female rat aorta. Ten-week-old female Wistar rats were divided into two groups: control (vehicle) and mercury treated (first dose of 4.6 μg/kg, subsequent daily doses of 0.07 μg/kg), im. Mercury treatment did not modify systolic blood pressure (SBP) but increased vascular reactivity due to the reduction of nitric oxide bioavailability associated with the increase in reactive oxygen species from endothelial nitric oxide synthase (eNOS) uncoupling. Furthermore, increased participation of the cyclooxygenase-2 pathway occurred through an imbalance in thromboxane 2 and prostacyclin 2. However, the oestrogen signalling pathway was not altered in either group. These results demonstrated that chronic exposure to mercury in females induced endothelial dysfunction and, consequently, increased aortic vascular reactivity, causing vascular damage to the female rat aorta and representing a risk of cardiovascular diseases.
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Affiliation(s)
| | - Dalton Valentim Vassallo
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil.,Health Science Center of Vitória, School of Sciences of Santa Casa de Misericórdia de Vitória - EMESCAM, Vitória, Espírito Santo, Brazil
| | - Maylla Ronacher Simões
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
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Effect of essential fatty acid blend on circadian variations of ambulatory blood pressure in patients with essential hypertension and coronary artery disease risk markers. J Hum Hypertens 2021; 36:289-298. [PMID: 33758346 DOI: 10.1038/s41371-021-00520-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 12/30/2020] [Accepted: 02/24/2021] [Indexed: 11/08/2022]
Abstract
Flaxseed oil is an excellent source of alpha-linolenic acid ALA known for its antihypertensive action. Flaxseed oil is unstable and its dose is not achievable in our conventional diet hence blending of natural flaxseed oil with palm oil, containing high flavonoids may be a better strategy, to stabilize the blend and provide proper balance of essential fatty acids and potential antioxidant effects. Aim of this study was to access the effect of blended flaxseed oil on 24 h 7-day circadian variations of blood pressure in subjects with essential hypertension. Assessment of CHAT (circadian hyper amplitude tension) using ABPM is the best marker for cardiovascular function. We registered 50 subjects with CAD (Group 1) and 50 subjects with Essential hypertension HT (Group 2) and 52 control subjects with CAD/Hypertension. Group 1 and 2 participant was supplemented with blended flaxseed oil (BFO) (30 ml/day) for the period of 24 weeks, while control group administered available oils sunflower in identical containers, for a follow-up period of 24 weeks. Twenty four hour seven days continuous ambulatory blood pressure monitoring was done initially and after six months of BFO supplementation. There were significant changes noted in lipid profile along with Ambulatory blood pressure parameters like MESOR, ACROPHASE, Hyperbaric Indexes, and CHAT. Circadian hyper amplitude tension (CHAT) incidence decreased after BFO supplementation. Study results suggest that blended flaxseed oil administration can be a potent natural vegetarian antihypertensive supplement which helps in synchronization of cardiac rhythms, and can be used as a preventive treatment of hypertension and as effective vegetarian source of maintaining Omega 3 and omega 6 ratios of essential fatty acids in the body.
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Bujok J, Miśta D, Wincewicz E, Króliczewska B, Dzimira S, Żuk M. Atherosclerosis Development and Aortic Contractility in Hypercholesterolemic Rabbits Supplemented with Two Different Flaxseed Varieties. Foods 2021; 10:534. [PMID: 33806676 PMCID: PMC8001360 DOI: 10.3390/foods10030534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 11/16/2022] Open
Abstract
Alpha-linolenic acid (ALA) is widely regarded as the main beneficial component of flax for the prevention of cardiovascular disease. We evaluated the effect of the transgenic flaxseed W86-which is rich in ALA-on the lipid profile, atherosclerosis progression, and vascular reactivity in hypercholesterolemic rabbits compared to the parental cultivar Linola with a very low ALA content. Rabbits were fed a basal diet (control) or a basal diet supplemented with 1% cholesterol, 1% cholesterol and 10% flaxseed W86, or 1% cholesterol and 10% Linola flaxseed. A high-cholesterol diet resulted in an elevated plasma cholesterol and triglyceride levels compared to the control animals. Aortic sections from rabbits fed Linola had lower deposits of foamy cells than those from rabbits fed W86. A potassium-induced and phenylephrine-induced contractile response was enhanced by a high-cholesterol diet and not influenced by the W86 or Linola flaxseed. Pretreatment of the aortic rings with nitro-L-arginine methyl ester resulted in a concentration-dependent tendency to increase the reaction amplitude in the control and high-cholesterol diet groups but not the flaxseed groups. Linola flaxseed with a low ALA content more effectively reduced the atherosclerosis progression compared with the W86 flaxseed with a high concentration of stable ALA. Aorta contractility studies suggested that flaxseed ameliorated an increased contractility in hypercholesterolemia but had little or no impact on NO synthesis in the vascular wall.
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Affiliation(s)
- Jolanta Bujok
- Department of Animal Physiology and Biostructure, Wroclaw University of Environmental and Life Sciences, C.K. Norwida 31, 50-375 Wrocław, Poland; (D.M.); (E.W.); (B.K.)
| | - Dorota Miśta
- Department of Animal Physiology and Biostructure, Wroclaw University of Environmental and Life Sciences, C.K. Norwida 31, 50-375 Wrocław, Poland; (D.M.); (E.W.); (B.K.)
| | - Edyta Wincewicz
- Department of Animal Physiology and Biostructure, Wroclaw University of Environmental and Life Sciences, C.K. Norwida 31, 50-375 Wrocław, Poland; (D.M.); (E.W.); (B.K.)
| | - Bożena Króliczewska
- Department of Animal Physiology and Biostructure, Wroclaw University of Environmental and Life Sciences, C.K. Norwida 31, 50-375 Wrocław, Poland; (D.M.); (E.W.); (B.K.)
| | - Stanisław Dzimira
- Department of Pathology, Wroclaw University of Environmental and Life Sciences, C.K. Norwida 31, 50-375 Wrocław, Poland;
| | - Magdalena Żuk
- Department of Genetic Biochemistry, Faculty of Biotechnology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wrocław, Poland;
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Piper K, Garelnabi M. Eicosanoids: Atherosclerosis and cardiometabolic health. J Clin Transl Endocrinol 2020; 19:100216. [PMID: 32071878 PMCID: PMC7013337 DOI: 10.1016/j.jcte.2020.100216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/22/2020] [Accepted: 02/01/2020] [Indexed: 02/08/2023] Open
Abstract
Cardiovascular diseases (CVD) have been the leading causes of death in the U.S. for nearly a century. Numerous studies have linked eicosanoids to cardiometabolic disease. Objectives and Methods: This review summaries recent advances and innovative research in eicosanoids and CVD. Numerous review articles and their original human or animal studies were assessed in the relevant and recent studies. OUTCOME We identified and discussed recent trends in eicosanoids known for their roles in CVD. Their subsequent relationships were assessed for any possible implications associated with consumption of different dietary lipids, essentially omega fatty acids. Eicosanoids have been heavily sought after over recent decades for their direct role in mediating the enhancement and resolution of acute immune responses. Given the short half-life of these oxidized lipid metabolites, studies on atherosclerosis have had to rely on the metabolites that are actively involved in eicosanoid production, signaling or redox reactions as markers for atherosclerosis-related molecular behaviors. CONCLUSION Further investigations expending current knowledge, should be applied to narrow the specific class and species of eicosanoids responsible for inciting inflammation especially in the context of recent clinical studies assessing the role of dietary lipid in cardiovascular diseases.
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de Carvalho EF, Gadelha KKL, de Oliveira DMN, Lima-Silva K, Batista-Lima FJ, de Brito TS, Paula SM, da Silva MTB, Dos Santos AA, Magalhães PJC. Neryl butyrate induces contractile effects on isolated preparations of rat aorta. Naunyn Schmiedebergs Arch Pharmacol 2019; 393:43-55. [PMID: 31420719 DOI: 10.1007/s00210-019-01709-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 08/06/2019] [Indexed: 02/07/2023]
Abstract
Neryl butyrate is a constituent of volatile oils obtained from aromatic plants. Aliphatic organic compound analogues chemically close to neryl butyrate possess vasodilator properties in rat aorta. To evaluate whether neryl butyrate has relaxing properties, this study tested its effects on isolated rat aorta. Unlike the analogues, neryl butyrate did not show relaxant profile in aortic rings precontracted with phenylephrine, but induced a contraction when it stimulated aortic rings under resting tonus. The contractile effect augmented in endothelium-denuded aortic rings. Treatment of endothelium-intact preparations with the nitric oxide synthase inhibitor L-NAME or the guanylyl cyclase inhibitor ODQ also augmented the contractile effect of neryl butyrate. Such phenomenon was absent in the presence of the cyclooxygenase inhibitor indomethacin. Contractile responses decreased in the presence of verapamil, a L-type Ca2+ channel blocker, or when Ca2+ was removed from the extracellular solution. Antagonists of α-adrenergic receptors (prazosin and yohimbine), but not the thromboxane-prostanoid receptor seratrodast, reversed the contraction induced by neryl butyrate. The α1A selective antagonist RS-17053 antagonized the neryl butyrate-induced contraction. The contraction caused by neryl butyrate was decreased by inhibiting the phospholipase C or the rho-associated kinase with U-73122 or Y-27632, respectively. Injected intravenously to awake rats, neryl butyrate induced arterial hypotension and bradycardia. Decreased frequency was also present in isolated right atrium preparations. In conclusion, the contractile effects of neryl butyrate were inhibited by α-adrenergic antagonists, indicating the involvement of α-adrenoceptors in the mechanism of action. In vivo, neryl butyrate caused hypotension, suggesting that other systemic influence than vasoconstriction may occur.
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Affiliation(s)
| | | | | | - Karine Lima-Silva
- Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, CE, Brazil
| | | | | | - Suliana Mesquita Paula
- Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, CE, Brazil
| | | | | | - Pedro Jorge Caldas Magalhães
- Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, CE, Brazil. .,Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará, R. Cel. Nunes de Melo 1315, Centro de Biomedicina, Rodolfo Teófilo, Fortaleza, CE, 60.430-270, Brazil.
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Effect of flaxseed consumption on flow-mediated dilation and inflammatory biomarkers in patients with coronary artery disease: a randomized controlled trial. Eur J Clin Nutr 2018; 73:258-265. [DOI: 10.1038/s41430-018-0268-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/18/2018] [Accepted: 07/05/2018] [Indexed: 12/23/2022]
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Simões FV, de Batista PR, Botelho T, Ribeiro-Júnior RF, Padilha AS, Vassallo DV. Treatment with high dose of atorvastatin reduces vascular injury in diabetic rats. Pharmacol Rep 2016; 68:865-73. [PMID: 27351941 DOI: 10.1016/j.pharep.2016.04.022] [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] [Received: 04/04/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Previous reports showed conflicting results regarding the treatment effects of statin on Diabetes mellitus (DM). We investigated how treatment with high dose of atorvastatin affects the impaired vascular function in diabetic rats. METHODS Atorvastatin (80mg/kg/day, oral gavage, 4 weeks) or its vehicle was administered to male control or streptozotocin (STZ)-induced diabetic rats. Aortic segments were used to investigate the vascular reactivity, protein expression of cyclooxygenase-2 (COX-2) and nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) 1 (NOX1) and superoxide anions levels. RESULTS Atorvastatin treatment did not affect glycemia levels. In diabetic rats, the vascular reactivity to phenylephrine increased compared with controls and the atorvastatin treatment reduced this response. Removal of the endothelium increased the response to phenylephrine in control rats, but not in the diabetic group. Atorvastatin increased the endothelial modulation in diabetic rats. L-NAME (100μM) increased the reactivity in all groups, but this effect was greater in atorvastatin-treated diabetic rats. Indomethacin (10μM) and NS398 (1μM) decreased the contractile response in diabetic rats and atorvastatin reversed these effects, without changing COX-2 expression. Apocynin (30μM) decreased the phenylephrine response in diabetic rats, which also showed increased NOX1 and superoxide anions; these effects were prevented by atorvastatin treatment. CONCLUSIONS The results suggest that treatment with high dose of atorvastatin, independent of glycemia, improves endothelial function in aortas from diabetic rats by reducing the constrictor prostanoids derived from COX-2 and by reducing the oxidative stress by NADPH oxidase, as well as a possible increasing of nitric oxide participation.
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Affiliation(s)
- Fabiana Vieira Simões
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Priscila Rossi de Batista
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Tatiani Botelho
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | | | - Alessandra Simão Padilha
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Dalton Valentim Vassallo
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil; Escola Superior de Ciências da Santa Casa de Misericórdia de Vitória (EMESCAM), Vitória, ES, Brazil.
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Ursoniu S, Sahebkar A, Andrica F, Serban C, Banach M. Effects of flaxseed supplements on blood pressure: A systematic review and meta-analysis of controlled clinical trial. Clin Nutr 2016; 35:615-25. [DOI: 10.1016/j.clnu.2015.05.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 05/04/2015] [Accepted: 05/19/2015] [Indexed: 12/22/2022]
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Rossi EM, Marques VB, Nunes DDO, Carneiro MTWD, Podratz PL, Merlo E, dos Santos L, Graceli JB. Acute iron overload leads to hypothalamic-pituitary-gonadal axis abnormalities in female rats. Toxicol Lett 2015; 240:196-213. [PMID: 26536400 DOI: 10.1016/j.toxlet.2015.10.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 10/28/2015] [Accepted: 10/28/2015] [Indexed: 01/01/2023]
Abstract
Iron plays a critical role in a mammal's physiological processes. However, iron tissue deposits have been shown to act as endocrine disrupters. Studies that evaluate the effect of acute iron overload on hypothalamic-pituitary-gonadal (HPG) axis health are particularly sparse. This study demonstrates that acute iron overload leads to HPG axis abnormalities, including iron accumulation and impairment in reproductive tract morphology. Female rats were treated with iron-dextran (Fe rats) to assess their HPG morphophysiology. The increasing serum iron levels due to iron-dextran treatment were positively correlated with higher iron accumulation in the HPG axis and uterus of Fe rats than in control rats. An increase in the production of superoxide anions was observed in the pituitary, uterus and ovary of Fe rats. Morphophysiological reproductive tract abnormalities, such as abnormal ovarian follicular development and the reduction of serum estrogen levels, were observed in Fe rats. In addition, a significant negative correlation was obtained between ovary superoxide anion and serum estrogen levels. Together, these data provide in vivo evidence that acute iron overload is toxic for the HPG axis, a finding that may be associated with the subsequent development of the risk of reproductive dysfunction.
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Affiliation(s)
- Emilly M Rossi
- Department of Physiological Sciences, Federal University of Espirito Santo, Brazil
| | - Vinicius B Marques
- Department of Physiological Sciences, Federal University of Espirito Santo, Brazil
| | - Dieli de O Nunes
- Department of Physiological Sciences, Federal University of Espirito Santo, Brazil
| | | | | | - Eduardo Merlo
- Department of Morphology, Federal University of Espirito Santo, Brazil
| | - Leonardo dos Santos
- Department of Physiological Sciences, Federal University of Espirito Santo, Brazil
| | - Jones B Graceli
- Department of Morphology, Federal University of Espirito Santo, Brazil.
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Marques VB, Nascimento TB, Ribeiro RF, Broseghini-Filho GB, Rossi EM, Graceli JB, dos Santos L. Chronic iron overload in rats increases vascular reactivity by increasing oxidative stress and reducing nitric oxide bioavailability. Life Sci 2015; 143:89-97. [PMID: 26523985 DOI: 10.1016/j.lfs.2015.10.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/13/2015] [Accepted: 10/28/2015] [Indexed: 02/07/2023]
Abstract
AIMS Iron overload in animal models and humans increases oxidative stress and induces cardiomyopathy. It has been suggested that the vasculature is also damaged, but the impacts on vascular reactivity and the underlying mechanisms remain poorly understood. In this study, we aimed to identify possible changes in the vascular reactivity of aortas from iron overloaded rats and investigate the underlying mechanisms. MAIN METHODS Rats were treated with 100mg/kg/day iron-dextran, ip, five days a week for four weeks and compared to a saline-injected group. KEY FINDINGS Chronic iron administration increased serum iron and transferrin saturation with significant deposition in the liver. Additionally, iron overload significantly increased the vasoconstrictor response in aortic rings as assessed in vitro, with reduced influence of endothelial denudation or l-NAME incubation on the vascular reactivity. In vitro assay with DAF-2 indicated reduced NO production in the iron overload group. Iron overload-induced vascular hyperactivity was reversed by incubation with tiron, catalase, apocynin, allopurinol and losartan. Moreover, malondialdehyde was elevated in the plasma, and O2(•-) generation and NADPH oxidase subunit (p22phox) expression were increased in the aortas of iron-loaded rats. SIGNIFICANCE Our results demonstrated that chronic iron overload is associated with altered vascular reactivity and the loss of endothelial modulation of the vascular tone. This iron loading-induced endothelial dysfunction and reduced nitric oxide bioavailability may be a result of increased production of reactive oxygen species and local renin-angiotensin system activation.
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Affiliation(s)
| | | | | | | | - Emilly Martinelly Rossi
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil
| | | | - Leonardo dos Santos
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil.
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