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

Detalhes bibliográficos
Autor(a) principal: Pinheiro, Gabriella Xavier Maretto
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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spelling 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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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
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