A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) |
Texto Completo: | http://repositorio.ufes.br/handle/10/7999 |
Resumo: | We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity.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. Following LNAME administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on Rmax were decreased compared to control subjects following superoxide dismutase administration, Catalase, 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. 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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Fioresi, MirianVassallo, Dalton ValentimNunes, Karolini ZuquiGouvea, Sonia AlvesMoyses, Margareth RibeiroPeçanha, Giulia Alessandra Wiggers2018-08-01T22:58:47Z2018-08-012018-08-01T22:58:47Z2014-12-17We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity.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. Following LNAME administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on Rmax were decreased compared to control subjects following superoxide dismutase administration, Catalase, 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. 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.Foi investigado os efeitos da exposição a baixas concentrações de chumbo na reatividade vascular. Ratos Wistars foram aleatoriamente classificados em dois grupos: controle (CT) e exposto à 100 ppm de acetato de chumbo (Pb) adicionado à água de beber durante 30 dias. A pressão arterial sistólica (PA) foi medida semanalmente. Após o tratamento, a reatividade vascular em anéis de aorta foi avaliada. As amostras de tecido foram devidamente armazenadas para posteriores investigações bioquímicas. Ao final do tratamento a concentração de chumbo no sangue foi de aproximadamente 8 μg/dL. A exposição ao chumbo aumentou a pressão arterial e diminuiu a resposta contrátil dos anéis de aorta à fenilefrina. Após a administração de L-NAME, as respostas contráteis aumentaram em ambos os grupos, mas não diferiram significativamente entre si. Os efeitos do chumbo sobre Rmáx foram diminuídos em comparação com grupo controle após a administração da superóxido dismutase, catalase e DETCA. A apocinina aumentou a resposta vasoconstritora induzida pela fenilefrina em aortas do grupo Pb, mas não aumentou a resposta vasoconstritora em aortas de ratos não do grupo Ct. O TEA potencializou a resposta vasoconstritora induzida pela fenilefrina em segmentos de aorta em ambos os grupos, mas estes efeitos foram maiores nos ratos do grupo Pb. A coincubação do TEA e catalase aboliu o efeito vasodilatador observado no grupo Pb. O cotratamento com ácido ascórbico reverteu a reatividade do grupo chumbo para situação controle. O presente estudo demonstrou que a concentração de chumbo no sangue abaixo dos valores estabelecidos pela legislação internacional foi capaz de aumentar a pressão arterial e diminuir a reatividade vascular induzida pela fenilefrina. Esse efeito foi relacionado com o estresse oxidativo induzido especificamente através do aumento nos níveis de peróxido de hidrogênio e os seus efeitos sobre os canais para potássio.Texthttp://repositorio.ufes.br/handle/10/7999porUniversidade Federal do Espírito SantoMestrado em Ciências FisiológicasPrograma de Pós-Graduação em Ciências FisiológicasUFESBRCentro de Ciências da SaúdeLead acetateHydrogen peroxideOxidative stressHypertensionAcetato de chumboAortaPeróxido de hidrogênioEstresse oxidativoHipertensãoFisiologia612A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênioinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)instname:Universidade Federal do Espírito Santo (UFES)instacron:UFESORIGINALtese_8474_Dissertação Karolini Zuqui Nunes20150211-114634.pdfapplication/pdf1582561http://repositorio.ufes.br/bitstreams/3749c841-ce36-46b2-b7cf-9b67873df220/downloadf4b44f21b78ef9e1d864c9df6ce770abMD5110/79992024-06-27 10:58:59.851oai:repositorio.ufes.br:10/7999http://repositorio.ufes.brRepositório InstitucionalPUBhttp://repositorio.ufes.br/oai/requestopendoar:21082024-06-27T10:58:59Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) - Universidade Federal do Espírito Santo (UFES)false |
dc.title.none.fl_str_mv |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
title |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
spellingShingle |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio Nunes, Karolini Zuqui Lead acetate Hydrogen peroxide Oxidative stress Hypertension Acetato de chumbo Aorta Peróxido de hidrogênio Estresse oxidativo Hipertensão Fisiologia 612 |
title_short |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
title_full |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
title_fullStr |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
title_full_unstemmed |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
title_sort |
A exposição crônica ao chumbo diminui a reatividade vascular em aorta de ratos: papel do peróxido de hidrogênio |
author |
Nunes, Karolini Zuqui |
author_facet |
Nunes, Karolini Zuqui |
author_role |
author |
dc.contributor.advisor-co1.fl_str_mv |
Fioresi, Mirian |
dc.contributor.advisor1.fl_str_mv |
Vassallo, Dalton Valentim |
dc.contributor.author.fl_str_mv |
Nunes, Karolini Zuqui |
dc.contributor.referee1.fl_str_mv |
Gouvea, Sonia Alves |
dc.contributor.referee2.fl_str_mv |
Moyses, Margareth Ribeiro |
dc.contributor.referee3.fl_str_mv |
Peçanha, Giulia Alessandra Wiggers |
contributor_str_mv |
Fioresi, Mirian Vassallo, Dalton Valentim Gouvea, Sonia Alves Moyses, Margareth Ribeiro Peçanha, Giulia Alessandra Wiggers |
dc.subject.eng.fl_str_mv |
Lead acetate Hydrogen peroxide Oxidative stress Hypertension |
topic |
Lead acetate Hydrogen peroxide Oxidative stress Hypertension Acetato de chumbo Aorta Peróxido de hidrogênio Estresse oxidativo Hipertensão Fisiologia 612 |
dc.subject.por.fl_str_mv |
Acetato de chumbo Aorta Peróxido de hidrogênio Estresse oxidativo Hipertensão |
dc.subject.cnpq.fl_str_mv |
Fisiologia |
dc.subject.udc.none.fl_str_mv |
612 |
description |
We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity.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. Following LNAME administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on Rmax were decreased compared to control subjects following superoxide dismutase administration, Catalase, 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. 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. |
publishDate |
2014 |
dc.date.issued.fl_str_mv |
2014-12-17 |
dc.date.accessioned.fl_str_mv |
2018-08-01T22:58:47Z |
dc.date.available.fl_str_mv |
2018-08-01 2018-08-01T22:58:47Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufes.br/handle/10/7999 |
url |
http://repositorio.ufes.br/handle/10/7999 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
Text |
dc.publisher.none.fl_str_mv |
Universidade Federal do Espírito Santo Mestrado em Ciências Fisiológicas |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Ciências Fisiológicas |
dc.publisher.initials.fl_str_mv |
UFES |
dc.publisher.country.fl_str_mv |
BR |
dc.publisher.department.fl_str_mv |
Centro de Ciências da Saúde |
publisher.none.fl_str_mv |
Universidade Federal do Espírito Santo Mestrado em Ciências Fisiológicas |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) instname:Universidade Federal do Espírito Santo (UFES) instacron:UFES |
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Universidade Federal do Espírito Santo (UFES) |
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UFES |
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UFES |
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Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) |
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Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) |
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