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Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide

We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity. Male Wistar rats were sorted randomly into the following two groups: control (Ct) and treatment with 100 ppm of lead (Pb), which was added to drinking water, for 30 days. Systolic blood pr...

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Autores principales: Nunes, Karolini Zuqui, Nunes, Dieli Oliveira, Silveira, Edna Aparecida, Cruz Pereira, Camila Almenara, Broseghini Filho, Gilson Brás, Vassallo, Dalton Valentim, Fioresi, Mirian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4373949/
https://www.ncbi.nlm.nih.gov/pubmed/25807237
http://dx.doi.org/10.1371/journal.pone.0120965
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author Nunes, Karolini Zuqui
Nunes, Dieli Oliveira
Silveira, Edna Aparecida
Cruz Pereira, Camila Almenara
Broseghini Filho, Gilson Brás
Vassallo, Dalton Valentim
Fioresi, Mirian
author_facet Nunes, Karolini Zuqui
Nunes, Dieli Oliveira
Silveira, Edna Aparecida
Cruz Pereira, Camila Almenara
Broseghini Filho, Gilson Brás
Vassallo, Dalton Valentim
Fioresi, Mirian
author_sort Nunes, Karolini Zuqui
collection PubMed
description We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity. Male Wistar rats were sorted randomly into the following two groups: control (Ct) and treatment with 100 ppm of lead (Pb), which was added to drinking water, for 30 days. Systolic blood pressure (BP) was measured weekly. Following treatment, aortic ring vascular reactivity was assessed. Tissue samples were properly stored for further biochemical investigation. The lead concentration in the blood reached approximately 8 μg/dL. Treatment increased blood pressure and decreased the contractile responses of the aortic rings to phenylephrine (1 nM–100 mM). Following N-nitro-L arginine methyl ester (L-NAME) administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on R(max) were decreased compared to control subjects following superoxide dismutase (SOD) administration. Catalase, diethyldithiocarbamic acid (DETCA), and apocynin increased the vasoconstrictor response induced by phenylephrine in the aortas of lead-treated rats but did not increase the vasoconstrictor response in the aortas of untreated rats. Tetraethylammonium (TEA) potentiated the vasoconstrictor response induced by phenylephrine in aortic segments in both groups, but these effects were greater in lead-treated rats. The co-incubation of TEA and catalase abolished the vasodilatory effect noted in the lead group. The present study is the first to demonstrate that blood lead concentrations well below the values established by international legislation increased blood pressure and decreased phenylephrine-induced vascular reactivity. The latter effect was associated with oxidative stress, specifically oxidative stress induced via increases in hydrogen peroxide levels and the subsequent effects of hydrogen peroxide on potassium channels.
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spelling pubmed-43739492015-03-27 Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide Nunes, Karolini Zuqui Nunes, Dieli Oliveira Silveira, Edna Aparecida Cruz Pereira, Camila Almenara Broseghini Filho, Gilson Brás Vassallo, Dalton Valentim Fioresi, Mirian PLoS One Research Article We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity. Male Wistar rats were sorted randomly into the following two groups: control (Ct) and treatment with 100 ppm of lead (Pb), which was added to drinking water, for 30 days. Systolic blood pressure (BP) was measured weekly. Following treatment, aortic ring vascular reactivity was assessed. Tissue samples were properly stored for further biochemical investigation. The lead concentration in the blood reached approximately 8 μg/dL. Treatment increased blood pressure and decreased the contractile responses of the aortic rings to phenylephrine (1 nM–100 mM). Following N-nitro-L arginine methyl ester (L-NAME) administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on R(max) were decreased compared to control subjects following superoxide dismutase (SOD) administration. Catalase, diethyldithiocarbamic acid (DETCA), and apocynin increased the vasoconstrictor response induced by phenylephrine in the aortas of lead-treated rats but did not increase the vasoconstrictor response in the aortas of untreated rats. Tetraethylammonium (TEA) potentiated the vasoconstrictor response induced by phenylephrine in aortic segments in both groups, but these effects were greater in lead-treated rats. The co-incubation of TEA and catalase abolished the vasodilatory effect noted in the lead group. The present study is the first to demonstrate that blood lead concentrations well below the values established by international legislation increased blood pressure and decreased phenylephrine-induced vascular reactivity. The latter effect was associated with oxidative stress, specifically oxidative stress induced via increases in hydrogen peroxide levels and the subsequent effects of hydrogen peroxide on potassium channels. Public Library of Science 2015-03-25 /pmc/articles/PMC4373949/ /pubmed/25807237 http://dx.doi.org/10.1371/journal.pone.0120965 Text en © 2015 Nunes et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Nunes, Karolini Zuqui
Nunes, Dieli Oliveira
Silveira, Edna Aparecida
Cruz Pereira, Camila Almenara
Broseghini Filho, Gilson Brás
Vassallo, Dalton Valentim
Fioresi, Mirian
Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title_full Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title_fullStr Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title_full_unstemmed Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title_short Chronic Lead Exposure Decreases the Vascular Reactivity of Rat Aortas: The Role of Hydrogen Peroxide
title_sort chronic lead exposure decreases the vascular reactivity of rat aortas: the role of hydrogen peroxide
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4373949/
https://www.ncbi.nlm.nih.gov/pubmed/25807237
http://dx.doi.org/10.1371/journal.pone.0120965
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