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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...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2015
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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. |
format | Online Article Text |
id | pubmed-4373949 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
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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