Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais
Autor(a) principal: | |
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Data de Publicação: | 2012 |
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/10/7971 |
Resumo: | Poisoning by organophosphate pesticides is often accompanied by cardiac complications which may be serious and even fatal. However, the effects of these compounds on the cardiovascular mechanisms involved in blood pressure regulation remain unknown. The aim of this study was to evaluate the effects of the administration of a single sublethal dose (8 mg/kg, i.p.) of the organophosphorus insecticide methamidophos on the Bezold-Jarisch reflex (BJR) and on the chemoreflex, as well as the effects of this administration on the activity of the plasma cholinesterase (ChE), creatin kinase-MB (CK-MB) and lactate dehydrogenase (LDH). For the protocols involving the cardiovascular reflexes, male Wistar rats were treated with single intraperitoneal injections of methamidophos (8 mg/kg; n=23; MTF group) or saline (0.9%, n=20; control group, CON). Twenty four hours after the injection procedure the animals underwent catheterization of the femoral artery and vein to allow pressure recordings and drugs administration, respectively. Cardiovascular recordings were performed 24 hours after the catheterization procedures. The chemoreflex and BJR were activated by intravenous (i.v.) injections randomly assigned of KCN (10, 20, 40 and 80 µg/rat) and phenylbiguanide (PBG, 1.5, 3, 6, 12 and 24 µg/kg), respectively. The bradycardic responses of the BJR were expressed as % of fall compared to baseline levels, while the chemoreflex responses were expressed as delta mean arterial pressure and heart rate. Separated groups of rats were treated similarly for the protocols involving measurement of the ChE (n=10/group), CK-MB (n=10/group) and LDH (n=9/group) and blood samples collected 24 h after the treatment. The statistical analysis used for the cardiovascular reflexes was one-way ANOVA for repeated measures followed by the Fisher's post hoc test and for the enzymatic protocols was the Student's t-test. The bradycardic component of the chemoreflex and of the BJR was significantly attenuated in animals treated with methamidophos. Similarly, the cholinesterase activity was significantly reduced in animals treated with this compound. However, no statistical differences were observed in the CK-MB and LDH activities between the studied groups (CON and MTF). Our data show that the acute treatment with methamidophos impairs the function of two cardiovascular reflexes, which could contribute to the cardiovascular complications observed in the acute poisoning by these compounds. |
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Sampaio, Karla NíveaFigueiredo, Suely Gomes dePinheiro, Gabriella Xavier MarettoVasquez, Elisardo CorralAndrade, Tadeu Uggere de2018-08-01T22:58:42Z2018-08-012018-08-01T22:58:42Z2012-06-29Poisoning by organophosphate pesticides is often accompanied by cardiac complications which may be serious and even fatal. However, the effects of these compounds on the cardiovascular mechanisms involved in blood pressure regulation remain unknown. The aim of this study was to evaluate the effects of the administration of a single sublethal dose (8 mg/kg, i.p.) of the organophosphorus insecticide methamidophos on the Bezold-Jarisch reflex (BJR) and on the chemoreflex, as well as the effects of this administration on the activity of the plasma cholinesterase (ChE), creatin kinase-MB (CK-MB) and lactate dehydrogenase (LDH). For the protocols involving the cardiovascular reflexes, male Wistar rats were treated with single intraperitoneal injections of methamidophos (8 mg/kg; n=23; MTF group) or saline (0.9%, n=20; control group, CON). Twenty four hours after the injection procedure the animals underwent catheterization of the femoral artery and vein to allow pressure recordings and drugs administration, respectively. Cardiovascular recordings were performed 24 hours after the catheterization procedures. The chemoreflex and BJR were activated by intravenous (i.v.) injections randomly assigned of KCN (10, 20, 40 and 80 µg/rat) and phenylbiguanide (PBG, 1.5, 3, 6, 12 and 24 µg/kg), respectively. The bradycardic responses of the BJR were expressed as % of fall compared to baseline levels, while the chemoreflex responses were expressed as delta mean arterial pressure and heart rate. Separated groups of rats were treated similarly for the protocols involving measurement of the ChE (n=10/group), CK-MB (n=10/group) and LDH (n=9/group) and blood samples collected 24 h after the treatment. The statistical analysis used for the cardiovascular reflexes was one-way ANOVA for repeated measures followed by the Fisher's post hoc test and for the enzymatic protocols was the Student's t-test. The bradycardic component of the chemoreflex and of the BJR was significantly attenuated in animals treated with methamidophos. Similarly, the cholinesterase activity was significantly reduced in animals treated with this compound. However, no statistical differences were observed in the CK-MB and LDH activities between the studied groups (CON and MTF). Our data show that the acute treatment with methamidophos impairs the function of two cardiovascular reflexes, which could contribute to the cardiovascular complications observed in the acute poisoning by these compounds.Intoxicações por compostos organofosforados são muitas vezes acompanhadas por complicações cardíacas, que podem ser graves e até fatais. No entanto, os efeitos desses compostos sobre os mecanismos cardiovasculares envolvidos na regulação da pressão arterial não são conhecidos. O objetivo desse estudo foi avaliar os efeitos da administração de uma dose subletal (8 mg/kg, i.p.) do organofosforado metamidofós sobre o reflexo Bezold-Jarisch (RBJ) e sobre o quimiorreflexo, bem como os efeitos desta administração sobre a atividade das enzimas colinesterase plasmática (ChE), creatina quinase-MB (CK-MB) e desidrogenase láctica (LDH). Para os protocolos envolvendo os reflexos cardiovasculares, ratos machos Wistar foram tratados com injeções intraperitoniais únicas de metamidofós (8,0 mg/kg; n=23; grupo MTF) ou solução salina (0,9%; n=20; grupo controle, CON). Vinte quatro horas após as injeções, os animais foram submetidos à cateterização da artéria e veia femorais para registros pressóricos e administração de drogas, respectivamente. Os registros cardiovasculares foram realizados 24 horas após os procedimentos cirúrgicos de cateterização. O quimiorreflexo e o RBJ foram ativados por administração intravenosa (i.v.) aleatória de doses crescentes de KCN (10, 20, 40 e 80 µg/rato) e fenilbiguanida (FBG; 1,5; 3,0; 6,0; 12 e 24 µg/kg), respectivamente. As respostas bradicárdicas do RBJ foram expressas como % de queda em relação aos níveis basais. Grupos separados de ratos, submetidos ao mesmo protocolo de tratamento, foram usados para os protocolos de dosagem das atividades de ChE (n=10/grupo), CK-MB (n=10/grupo) e LDH (n=9/grupo) e as amostras de sangue coletadas 24 horas após o tratamento. A análise estatística empregada para avaliação dos reflexos foi análise de variância (ANOVA) de uma via para medidas repetidas, com análise Post-Hoc pelo teste de Fisher e para as dosagens enzimáticas, o teste t-Student. O componente bradicárdico do quimiorreflexo e RBJ foi significativamente atenuado em animais tratados com metamidofós. Do mesmo modo, a atividade colinesterásica foi significativamente reduzida nos animais tratados com este composto. No entanto, não foram observadas diferenças estatisticamente significantes nas atividades de CK-MB e LDH entre os grupos estudados (CON e MTF). Nossos dados mostram que o tratamento agudo com o metamidofós prejudica a função de dois reflexos cardiovasculares, o que poderia contribuir para as complicações cardiovasculares observadas na intoxicação aguda por estes compostos.Texthttp://repositorio.ufes.br/handle/10/7971porUniversidade Federal do Espírito SantoMestrado em Ciências FisiológicasPrograma de Pós-Graduação em Ciências FisiológicasUFESBRCentro de Ciências da SaúdeMethamidophosBezold-Jarisch reflexChemorereceptor reflexCardiovascular functionCholinesteraseCK-MBLDHMetamidofósReflexo Bezold-JarischQuimiorreflexoFunção cardiovascularColinesteraseFisiologia612Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentaisinfo: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_5836_Dissertação Gabriella Xavier Maretto Pinheiro.pdfapplication/pdf4150182http://repositorio.ufes.br/bitstreams/d599fe2b-2103-4129-aab5-9365134ceca7/download78691a09d040c84621d0862f530061bcMD5110/79712024-07-16 17:07:23.627oai:repositorio.ufes.br:10/7971http://repositorio.ufes.brRepositório InstitucionalPUBhttp://repositorio.ufes.br/oai/requestopendoar:21082024-10-15T17:54:02.982240Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) - Universidade Federal do Espírito Santo (UFES)false |
dc.title.none.fl_str_mv |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
title |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
spellingShingle |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais Pinheiro, Gabriella Xavier Maretto Methamidophos Bezold-Jarisch reflex Chemorereceptor reflex Cardiovascular function Cholinesterase CK-MB LDH Metamidofós Reflexo Bezold-Jarisch Quimiorreflexo Função cardiovascular Colinesterase Fisiologia 612 |
title_short |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
title_full |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
title_fullStr |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
title_full_unstemmed |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
title_sort |
Avaliação dos efeitos tóxicos da exposição ao inseticida, fosforoamidotioato de O,S-Dimetila (Metamidofós) sobre o reflexo Bezold-Jarisch e sobre o quimiorreflexo em animais experimentais |
author |
Pinheiro, Gabriella Xavier Maretto |
author_facet |
Pinheiro, Gabriella Xavier Maretto |
author_role |
author |
dc.contributor.advisor-co1.fl_str_mv |
Sampaio, Karla Nívea |
dc.contributor.advisor1.fl_str_mv |
Figueiredo, Suely Gomes de |
dc.contributor.author.fl_str_mv |
Pinheiro, Gabriella Xavier Maretto |
dc.contributor.referee1.fl_str_mv |
Vasquez, Elisardo Corral |
dc.contributor.referee2.fl_str_mv |
Andrade, Tadeu Uggere de |
contributor_str_mv |
Sampaio, Karla Nívea Figueiredo, Suely Gomes de Vasquez, Elisardo Corral Andrade, Tadeu Uggere de |
dc.subject.eng.fl_str_mv |
Methamidophos Bezold-Jarisch reflex Chemorereceptor reflex Cardiovascular function Cholinesterase |
topic |
Methamidophos Bezold-Jarisch reflex Chemorereceptor reflex Cardiovascular function Cholinesterase CK-MB LDH Metamidofós Reflexo Bezold-Jarisch Quimiorreflexo Função cardiovascular Colinesterase Fisiologia 612 |
dc.subject.por.fl_str_mv |
CK-MB LDH Metamidofós Reflexo Bezold-Jarisch Quimiorreflexo Função cardiovascular Colinesterase |
dc.subject.cnpq.fl_str_mv |
Fisiologia |
dc.subject.udc.none.fl_str_mv |
612 |
description |
Poisoning by organophosphate pesticides is often accompanied by cardiac complications which may be serious and even fatal. However, the effects of these compounds on the cardiovascular mechanisms involved in blood pressure regulation remain unknown. The aim of this study was to evaluate the effects of the administration of a single sublethal dose (8 mg/kg, i.p.) of the organophosphorus insecticide methamidophos on the Bezold-Jarisch reflex (BJR) and on the chemoreflex, as well as the effects of this administration on the activity of the plasma cholinesterase (ChE), creatin kinase-MB (CK-MB) and lactate dehydrogenase (LDH). For the protocols involving the cardiovascular reflexes, male Wistar rats were treated with single intraperitoneal injections of methamidophos (8 mg/kg; n=23; MTF group) or saline (0.9%, n=20; control group, CON). Twenty four hours after the injection procedure the animals underwent catheterization of the femoral artery and vein to allow pressure recordings and drugs administration, respectively. Cardiovascular recordings were performed 24 hours after the catheterization procedures. The chemoreflex and BJR were activated by intravenous (i.v.) injections randomly assigned of KCN (10, 20, 40 and 80 µg/rat) and phenylbiguanide (PBG, 1.5, 3, 6, 12 and 24 µg/kg), respectively. The bradycardic responses of the BJR were expressed as % of fall compared to baseline levels, while the chemoreflex responses were expressed as delta mean arterial pressure and heart rate. Separated groups of rats were treated similarly for the protocols involving measurement of the ChE (n=10/group), CK-MB (n=10/group) and LDH (n=9/group) and blood samples collected 24 h after the treatment. The statistical analysis used for the cardiovascular reflexes was one-way ANOVA for repeated measures followed by the Fisher's post hoc test and for the enzymatic protocols was the Student's t-test. The bradycardic component of the chemoreflex and of the BJR was significantly attenuated in animals treated with methamidophos. Similarly, the cholinesterase activity was significantly reduced in animals treated with this compound. However, no statistical differences were observed in the CK-MB and LDH activities between the studied groups (CON and MTF). Our data show that the acute treatment with methamidophos impairs the function of two cardiovascular reflexes, which could contribute to the cardiovascular complications observed in the acute poisoning by these compounds. |
publishDate |
2012 |
dc.date.issued.fl_str_mv |
2012-06-29 |
dc.date.accessioned.fl_str_mv |
2018-08-01T22:58:42Z |
dc.date.available.fl_str_mv |
2018-08-01 2018-08-01T22:58:42Z |
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info:eu-repo/semantics/publishedVersion |
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info:eu-repo/semantics/masterThesis |
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masterThesis |
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publishedVersion |
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http://repositorio.ufes.br/handle/10/7971 |
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http://repositorio.ufes.br/handle/10/7971 |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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Text |
dc.publisher.none.fl_str_mv |
Universidade Federal do Espírito Santo Mestrado em Ciências Fisiológicas |
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Programa de Pós-Graduação em Ciências Fisiológicas |
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UFES |
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BR |
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Centro de Ciências da Saúde |
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Universidade Federal do Espírito Santo Mestrado em Ciências Fisiológicas |
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Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) |
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