Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos

Detalhes bibliográficos
Autor(a) principal: Barreto, George Emílio Sampaio
Data de Publicação: 2005
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da UFRN
Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/13428
Resumo: Aim: The aim of this work was to investigate the hypothesis that catechol and 3MC inhibit FADH2-linked basal respiration in mitochondria isolated from rat liver and brain homogenates. Moreover, catechol ability to induce DNA damage in rat brain cells through the comet assay (alkaline single-cell gel electrophoresis assay) was also observed. Methods: Two different catechols were evaluated: pirocatechol (derived from benzene) and 3-methylcatechol (derived from toluene); rat liver and brain homogenates were incubated with 1mM catechol at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate for a period of 12 minutes. In additional experiments, rat brain cells were treated with 1, 5 and 10mM pirocatechol for up to 20 minutes at 37º C, and submitted to electrophoresis. Results: Catechols (pirocatechol and 3methylcatechol) induced a time-dependent partial inhibition of FADH2-linked basal mitochondrial respiration. Indeed, pirocatechol was able to produce a dosedependent DNA oxidative damage in rat brain cells by 2 and 4 injury levels. These results suggest that reactive oxygen species generated by the oxidation of catechols, induced an impairment on mitochondrial respiration and a DNA damage, which might be related to their citotoxicity. Conclusion: Catechols produced an inhibition of basal respiration associated to FADH2 in isolated liver and brain mitochondria; 3-methylcatechol, at the same concentration, produced similar toxicity in the mitochondrial model. Indeed, pirocatechol induced a DNA damage in rat brain cells, mainly observed in comets formation and consequent DNA degradation
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spelling Barreto, George Emílio Sampaiohttp://lattes.cnpq.br/3703574626920154http://lattes.cnpq.br/6907806915889763El-bachá, Ramon dos Santoshttp://lattes.cnpq.br/3043273291222024Soares, Luíz Alberto LiraEgito, Eryvaldo Sócrates Tabosa do2014-12-17T14:14:04Z2007-08-242014-12-17T14:14:04Z2005-11-03BARRETO, George Emílio Sampaio. Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos. 2005. 124 f. Dissertação (Mestrado em Ciências da Saúde) - Universidade Federal do Rio Grande do Norte, Natal, 2005.https://repositorio.ufrn.br/jspui/handle/123456789/13428Aim: The aim of this work was to investigate the hypothesis that catechol and 3MC inhibit FADH2-linked basal respiration in mitochondria isolated from rat liver and brain homogenates. Moreover, catechol ability to induce DNA damage in rat brain cells through the comet assay (alkaline single-cell gel electrophoresis assay) was also observed. Methods: Two different catechols were evaluated: pirocatechol (derived from benzene) and 3-methylcatechol (derived from toluene); rat liver and brain homogenates were incubated with 1mM catechol at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate for a period of 12 minutes. In additional experiments, rat brain cells were treated with 1, 5 and 10mM pirocatechol for up to 20 minutes at 37º C, and submitted to electrophoresis. Results: Catechols (pirocatechol and 3methylcatechol) induced a time-dependent partial inhibition of FADH2-linked basal mitochondrial respiration. Indeed, pirocatechol was able to produce a dosedependent DNA oxidative damage in rat brain cells by 2 and 4 injury levels. These results suggest that reactive oxygen species generated by the oxidation of catechols, induced an impairment on mitochondrial respiration and a DNA damage, which might be related to their citotoxicity. Conclusion: Catechols produced an inhibition of basal respiration associated to FADH2 in isolated liver and brain mitochondria; 3-methylcatechol, at the same concentration, produced similar toxicity in the mitochondrial model. Indeed, pirocatechol induced a DNA damage in rat brain cells, mainly observed in comets formation and consequent DNA degradationObjetivo Testar a hipótese de catecóis inibirem a respiração basal associada ao FADH2 em frações mitocondriais hepáticas e cerebrais de rato. Também, procurou-se estudar a ocorrência de danos no DNA induzidos por catecol em células de cérebro de ratos. Métodos: Foram avaliados dois catecóis: O pirocatecol (derivado do benzeno) e o 3-metilcatecol (derivado do tolueno); Os homogeneizados de fígado e cérebro de ratos foram incubados com catecol a 1 mM em pH fisiológico. Depois disso, as frações mitocondriais foram isoladas por centrifugação diferencial. O consumo basal de oxigênio foi medido com um eletrodo do tipo Clark após injeção de succinato a 10 mM, e o consumo foi observado por 12 minutos. Em experimentos adicionais, amostras de tecidos cerebrais foram tratadas com pirocatecol em diferentes concentrações (1 mM, 5 mM e 10 mM), durante 0 (sem incubação), 10 e 20 minutos a 37°C, e posteriormente submetidas a el etroforese. Resultados: Os resultados demonstram que os catecóis induziram uma inibição parcial da respiração basal mitocondrial associada ao FADH2 de forma dependente do tempo. Já no caso dos experimentos com o ensaio cometa, os dados obtidos demonstram um aumento na ocorrência de cometas de níveis 2 a 4 de forma dose dependente, sugerindo que as espécies reativas de oxigênio geradas pela oxidação do catecol induzem danos de DNA, o que pode também estar relacionado com citotoxicidade deste composto. Conclusão O pirocatecol produz inibição da respiração basal associada ao FADH2 em mitocôndrias isoladas de fígado e cérebro de ratos; o 3-metilcatecol, nessa mesma concentração, produziu toxicidade semelhante no modelo mitocondrial. Adicionalmente, o pirocatecol induziu a um dano de DNA em células cerebrais de ratos, observado na formação de cometas e conseqüente degradação do DNAFundação de Amparo a Pesquisa do Estado da Bahiaapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em Ciências da SaúdeUFRNBRCiências da SaúdeBenzenotoluenocatecóisradicais livresrespiraçãoBenzeneTolueneCatecholsFree radicalsRespirationCNPQ::CIENCIAS DA SAUDEEstudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratosinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALEstudoEfeitoMetabólitos_Barreto_2005.pdfapplication/pdf1518565https://repositorio.ufrn.br/bitstream/123456789/13428/1/EstudoEfeitoMetab%c3%b3litos_Barreto_2005.pdfbcd5e83ea0cd501b6573d93e3ef15380MD51TEXTGeorgeESC.pdf.txtGeorgeESC.pdf.txtExtracted texttext/plain223746https://repositorio.ufrn.br/bitstream/123456789/13428/6/GeorgeESC.pdf.txt3d753de3d343835ec21b69a7fd7bed1cMD56EstudoEfeitoMetabólitos_Barreto_2005.pdf.txtEstudoEfeitoMetabólitos_Barreto_2005.pdf.txtExtracted texttext/plain223348https://repositorio.ufrn.br/bitstream/123456789/13428/8/EstudoEfeitoMetab%c3%b3litos_Barreto_2005.pdf.txtdd92d764dc82a1047d6978cdc6597be6MD58THUMBNAILGeorgeESC.pdf.jpgGeorgeESC.pdf.jpgIM Thumbnailimage/jpeg2146https://repositorio.ufrn.br/bitstream/123456789/13428/7/GeorgeESC.pdf.jpgee9559de5047c99a670bfd3373d73c82MD57EstudoEfeitoMetabólitos_Barreto_2005.pdf.jpgEstudoEfeitoMetabólitos_Barreto_2005.pdf.jpgGenerated Thumbnailimage/jpeg1241https://repositorio.ufrn.br/bitstream/123456789/13428/9/EstudoEfeitoMetab%c3%b3litos_Barreto_2005.pdf.jpg017e6c62abbeb5ec3522071c2335af23MD59123456789/134282019-05-26 02:21:54.315oai:https://repositorio.ufrn.br:123456789/13428Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2019-05-26T05:21:54Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false
dc.title.por.fl_str_mv Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
title Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
spellingShingle Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
Barreto, George Emílio Sampaio
Benzeno
tolueno
catecóis
radicais livres
respiração
Benzene
Toluene
Catechols
Free radicals
Respiration
CNPQ::CIENCIAS DA SAUDE
title_short Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
title_full Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
title_fullStr Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
title_full_unstemmed Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
title_sort Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos
author Barreto, George Emílio Sampaio
author_facet Barreto, George Emílio Sampaio
author_role author
dc.contributor.authorID.por.fl_str_mv
dc.contributor.authorLattes.por.fl_str_mv http://lattes.cnpq.br/3703574626920154
dc.contributor.advisorID.por.fl_str_mv
dc.contributor.advisorLattes.por.fl_str_mv http://lattes.cnpq.br/6907806915889763
dc.contributor.advisor-co1ID.por.fl_str_mv
dc.contributor.referees1.pt_BR.fl_str_mv Soares, Luíz Alberto Lira
dc.contributor.referees1ID.por.fl_str_mv
dc.contributor.author.fl_str_mv Barreto, George Emílio Sampaio
dc.contributor.advisor-co1.fl_str_mv El-bachá, Ramon dos Santos
dc.contributor.advisor-co1Lattes.fl_str_mv http://lattes.cnpq.br/3043273291222024
dc.contributor.advisor1.fl_str_mv Egito, Eryvaldo Sócrates Tabosa do
contributor_str_mv El-bachá, Ramon dos Santos
Egito, Eryvaldo Sócrates Tabosa do
dc.subject.por.fl_str_mv Benzeno
tolueno
catecóis
radicais livres
respiração
topic Benzeno
tolueno
catecóis
radicais livres
respiração
Benzene
Toluene
Catechols
Free radicals
Respiration
CNPQ::CIENCIAS DA SAUDE
dc.subject.eng.fl_str_mv Benzene
Toluene
Catechols
Free radicals
Respiration
dc.subject.cnpq.fl_str_mv CNPQ::CIENCIAS DA SAUDE
description Aim: The aim of this work was to investigate the hypothesis that catechol and 3MC inhibit FADH2-linked basal respiration in mitochondria isolated from rat liver and brain homogenates. Moreover, catechol ability to induce DNA damage in rat brain cells through the comet assay (alkaline single-cell gel electrophoresis assay) was also observed. Methods: Two different catechols were evaluated: pirocatechol (derived from benzene) and 3-methylcatechol (derived from toluene); rat liver and brain homogenates were incubated with 1mM catechol at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate for a period of 12 minutes. In additional experiments, rat brain cells were treated with 1, 5 and 10mM pirocatechol for up to 20 minutes at 37º C, and submitted to electrophoresis. Results: Catechols (pirocatechol and 3methylcatechol) induced a time-dependent partial inhibition of FADH2-linked basal mitochondrial respiration. Indeed, pirocatechol was able to produce a dosedependent DNA oxidative damage in rat brain cells by 2 and 4 injury levels. These results suggest that reactive oxygen species generated by the oxidation of catechols, induced an impairment on mitochondrial respiration and a DNA damage, which might be related to their citotoxicity. Conclusion: Catechols produced an inhibition of basal respiration associated to FADH2 in isolated liver and brain mitochondria; 3-methylcatechol, at the same concentration, produced similar toxicity in the mitochondrial model. Indeed, pirocatechol induced a DNA damage in rat brain cells, mainly observed in comets formation and consequent DNA degradation
publishDate 2005
dc.date.issued.fl_str_mv 2005-11-03
dc.date.available.fl_str_mv 2007-08-24
2014-12-17T14:14:04Z
dc.date.accessioned.fl_str_mv 2014-12-17T14:14:04Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
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status_str publishedVersion
dc.identifier.citation.fl_str_mv BARRETO, George Emílio Sampaio. Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos. 2005. 124 f. Dissertação (Mestrado em Ciências da Saúde) - Universidade Federal do Rio Grande do Norte, Natal, 2005.
dc.identifier.uri.fl_str_mv https://repositorio.ufrn.br/jspui/handle/123456789/13428
identifier_str_mv BARRETO, George Emílio Sampaio. Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos. 2005. 124 f. Dissertação (Mestrado em Ciências da Saúde) - Universidade Federal do Rio Grande do Norte, Natal, 2005.
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dc.publisher.none.fl_str_mv Universidade Federal do Rio Grande do Norte
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dc.publisher.initials.fl_str_mv UFRN
dc.publisher.country.fl_str_mv BR
dc.publisher.department.fl_str_mv Ciências da Saúde
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