Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular
Ano de defesa: | 2021 |
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Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Tese |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal da Paraíba
Brasil Ciências Fisiológicas Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas UFPB |
Programa de Pós-Graduação: |
Não Informado pela instituição
|
Departamento: |
Não Informado pela instituição
|
País: |
Não Informado pela instituição
|
Palavras-chave em Português: | |
Link de acesso: | https://repositorio.ufpb.br/jspui/handle/123456789/23055 |
Resumo: | Astrocytic cells modulate neuronal activity, including glutamate uptake from the extracellular environment. In renovascular hypertension (HRv) there is an increase in released glutamate by neurons in brainstem nuclei involved in the cardiovascular modulation, contributing to increasing pre-sympathetic neurons activity. However, it is not clear about the involvement of the astrocytes in the extracellular glutamate uptake and recycling in hypertension. This study aimed to analyze the astroglial participation in the uptake and glutamate recycling in the brainstem and hypothalamus in HRv rats. For this purpose, we performed guide-cannula implantation intracisterna magna (ICM) in SHAM and 2K1C rats (HRv model) for microinjections of: a) astrocytic glutamate transporter EAAT2 / GLT1 inhibitor [DHK (1mM)], b) astrocytic glutamine synthetase inhibitor [L-AAA (2mM)] and c) gliotoxin fluorocitrate [FCt (0.2mM)]. One group of animals (2K1C/LOS) was treated with Losartana (AT1 antagonist) by gavage at a dose of 30 mg/kg/day for 4 weeks. After femoral artery catheterization, we made cardiovascular measurements. For in vitro studies, we analyzed by western blotting the astrocytic cytoskeleton - glial fibrillary acid protein - (GFAP), the glutamate receptors (EAAT2 / GLT1 and EAAT1 / GLAST) and the enzyme glutamine synthetase (GS) protein expression. into subfornical organ (SFO), paraventricular nucleus (PVN), rostral ventrolateral brainstem (RVLM), solitary tract nucleus (NTS) and cortex (control area) regions. Our results showed that DHK, or L-AAA ICM microinjection did not change baseline MAP (mmHg) or HR (bpm) in SHAM, 2K1C or 2K1C/LOS groups. FCt ICM microinjection promoted an increase in MAP (mmHg) in the 2K1C group, but not SHAM or 2K1C/LOS. The western blotting analysis showed t in the RVLM a reduction in the GLT1 / EAAT2 and GLAST / EAAT1 transporters expression in the 2K1C. There was also a decrease in the GFAP and GS expression into NTS and RVLM of 2K1C rats. In addition, we observed a reduction in the GLAST / EAAT1 transporter expression into SFO and an increase in GFAP expression into PVN of 2K1C animals. Our results showed that inhibition of astrocytic glutamate transporters or GS on bulbar surface does not seem to be involved in the cardiovascular modulation in normotensive or 2K1C rats. However, glia appears to be involved with BP modulation in HRv. Furthermore, our in vitro studies showed HRv induce changes in the expression of different astrocytic protein in the brainstem hypothalamic nuclei involved with the cardiovascular modulation. In that regards, our studies suggest the involvement of glial cells in the modulation of blood pressure in HRv. However further studies are needed to better understand the participation of astrocytes to modulate cardiovascular function in hypertensive rats. |
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Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascularAstrócitosBulboAngiotensina IIHipertensão renovascularAstrocytesBrainstemAngiotensin IIRenovascular hypertensionCNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIAAstrocytic cells modulate neuronal activity, including glutamate uptake from the extracellular environment. In renovascular hypertension (HRv) there is an increase in released glutamate by neurons in brainstem nuclei involved in the cardiovascular modulation, contributing to increasing pre-sympathetic neurons activity. However, it is not clear about the involvement of the astrocytes in the extracellular glutamate uptake and recycling in hypertension. This study aimed to analyze the astroglial participation in the uptake and glutamate recycling in the brainstem and hypothalamus in HRv rats. For this purpose, we performed guide-cannula implantation intracisterna magna (ICM) in SHAM and 2K1C rats (HRv model) for microinjections of: a) astrocytic glutamate transporter EAAT2 / GLT1 inhibitor [DHK (1mM)], b) astrocytic glutamine synthetase inhibitor [L-AAA (2mM)] and c) gliotoxin fluorocitrate [FCt (0.2mM)]. One group of animals (2K1C/LOS) was treated with Losartana (AT1 antagonist) by gavage at a dose of 30 mg/kg/day for 4 weeks. After femoral artery catheterization, we made cardiovascular measurements. For in vitro studies, we analyzed by western blotting the astrocytic cytoskeleton - glial fibrillary acid protein - (GFAP), the glutamate receptors (EAAT2 / GLT1 and EAAT1 / GLAST) and the enzyme glutamine synthetase (GS) protein expression. into subfornical organ (SFO), paraventricular nucleus (PVN), rostral ventrolateral brainstem (RVLM), solitary tract nucleus (NTS) and cortex (control area) regions. Our results showed that DHK, or L-AAA ICM microinjection did not change baseline MAP (mmHg) or HR (bpm) in SHAM, 2K1C or 2K1C/LOS groups. FCt ICM microinjection promoted an increase in MAP (mmHg) in the 2K1C group, but not SHAM or 2K1C/LOS. The western blotting analysis showed t in the RVLM a reduction in the GLT1 / EAAT2 and GLAST / EAAT1 transporters expression in the 2K1C. There was also a decrease in the GFAP and GS expression into NTS and RVLM of 2K1C rats. In addition, we observed a reduction in the GLAST / EAAT1 transporter expression into SFO and an increase in GFAP expression into PVN of 2K1C animals. Our results showed that inhibition of astrocytic glutamate transporters or GS on bulbar surface does not seem to be involved in the cardiovascular modulation in normotensive or 2K1C rats. However, glia appears to be involved with BP modulation in HRv. Furthermore, our in vitro studies showed HRv induce changes in the expression of different astrocytic protein in the brainstem hypothalamic nuclei involved with the cardiovascular modulation. In that regards, our studies suggest the involvement of glial cells in the modulation of blood pressure in HRv. However further studies are needed to better understand the participation of astrocytes to modulate cardiovascular function in hypertensive rats.Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPqCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESOs Astrócitos modulam a atividade neuronal por meio de diferentes mecanismos, incluindo a recaptação de neurotransmissores do meio extracelular. Sabe-se que na hipertensão renovascular (HRv) há aumento na liberação do glutamato por neurônios de núcleos bulbares envolvidos com a modulação cardiovascular, contribuindo para o aumento da atividade de neurônios pré-simpáticos. Entretanto, pouco se sabe sobre a participação dos astrócitos na recaptação e conversão do glutamato na região do bulbo de ratos hipertensos. O objetivo deste estudo foi analisar a participação dos astrócitos na recaptação e reciclagem do glutamato no bulbo e no hipotálamo de ratos com HRv. Para tanto, realizamos o implante de cânula-guia na região intracisterna magna (ICM) de ratos normotensos e com HRv (pelo modelo 2 Rins -1 Clipe / 2R1C) para a realização das microinjeções: a) do Inibidor do transportador de glutamato astrocítico GLT1 [DHK (1 mM)], b) do inibidor da glutamina sintetase astrocítica [L-AAA (2 mM)] e c) da gliotoxina fluorocitrato [FCt (0,2 mM)]. Um grupo de animais com 2R1C foi tratado com Losartanaa (antagonista AT1) por gavagem na dose de 30mg/kg/dia durante 4 semanas após o período de estabilização do quadro hipertensivo. Para os estudos in vitro, realizamos, por meio da técnica de western blotting, a análise da expressão proteica do citoesqueleto astrocítico - glial fibrillary acid protein - (GFAP), dos recaptadores de glutamato (GLT1 e GLAST) e da enzima glutamina sintetase (GS) das regiões do órgão subfornicial (SFO), núcleo paraventricular do hipotálamo (PVN), bulbo ventrolateral rostral (RVLM), núcleo do trato solitário (NTS) e Córtex. Nossos resultados mostraram que a inibição dos transportadores de glutamato astrocíticos com o DHK ou a inibição da enzima GS com a L-AAA ICM não promoveu alterações cardiovasculares significativas entre os animais dos grupos SHAM, 2R1C e 2R1C/LOS. Entretanto, a inibição da atividade da glia com o FCt ICM promoveu aumento significativo pontual na pressão arterial média (PAM) dos animais 2R1C, mas não nos animais SHAM ou 2R1C/LOS. A análise da expressão proteica no bulbo mostrou que os animais hipertensos apresentaram redução da expressão dos transportadores GLT1 e GLAST no RVLM, bem como redução na expressão de GFAP e da GS no NTS e no RVLM. Na região do hipotálamo, observamos redução na expressão proteica do transportador GLAST no SFO e aumento na expressão de GFAP no PVN dos animais hipertensos. Nossos resultados mostraram que os transportadores de glutamato astrocíticos e a GS da superfície bulbar parecem não estar envolvidos com a modulação cardiovascular de animais normotensos ou 2R1C. Entretanto, a glia parece estar envolvida com a modulação da PAM nesta fisiopatologia. Além disso, nossos estudos in vitro mostraram alterações na expressão proteica de diferentes marcadores da atividade astrocítica nos núcleos bulbares (NTS e RVLM) e hipotalâmicos (SFO e PVN) de animais 2R1C. Nesse sentido, nossos estudos sugerem a participação das células da glia na modulação da pressão arterial na HRv, contudo são necessários estudos adicionais, para melhor compreendermos a participação dos astrócitos na modulação cardiovascular em ratos hipertensos.Universidade Federal da ParaíbaBrasilCiências FisiológicasPrograma Multicêntrico de Pós-Graduação em Ciências FisiológicasUFPBCruz, Josiane de Camposhttp://lattes.cnpq.br/7245505923489654Flôr, Atalia Ferreira de Lima2022-06-08T18:25:17Z2022-01-242022-06-08T18:25:17Z2021-11-26info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesishttps://repositorio.ufpb.br/jspui/handle/123456789/23055porAttribution-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nd/3.0/br/info:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFPBinstname:Universidade Federal da Paraíba (UFPB)instacron:UFPB2022-08-09T14:05:59Zoai:repositorio.ufpb.br:123456789/23055Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufpb.br/PUBhttp://tede.biblioteca.ufpb.br:8080/oai/requestdiretoria@ufpb.br|| diretoria@ufpb.bropendoar:2022-08-09T14:05:59Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB)false |
dc.title.none.fl_str_mv |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
title |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
spellingShingle |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular Flôr, Atalia Ferreira de Lima Astrócitos Bulbo Angiotensina II Hipertensão renovascular Astrocytes Brainstem Angiotensin II Renovascular hypertension CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA |
title_short |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
title_full |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
title_fullStr |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
title_full_unstemmed |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
title_sort |
Estudo dos mecanismos glutamatérgicos astrogliais do bulbo e hipotálamo na modulação cardiovascular em ratos com hipertensão renovascular |
author |
Flôr, Atalia Ferreira de Lima |
author_facet |
Flôr, Atalia Ferreira de Lima |
author_role |
author |
dc.contributor.none.fl_str_mv |
Cruz, Josiane de Campos http://lattes.cnpq.br/7245505923489654 |
dc.contributor.author.fl_str_mv |
Flôr, Atalia Ferreira de Lima |
dc.subject.por.fl_str_mv |
Astrócitos Bulbo Angiotensina II Hipertensão renovascular Astrocytes Brainstem Angiotensin II Renovascular hypertension CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA |
topic |
Astrócitos Bulbo Angiotensina II Hipertensão renovascular Astrocytes Brainstem Angiotensin II Renovascular hypertension CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA |
description |
Astrocytic cells modulate neuronal activity, including glutamate uptake from the extracellular environment. In renovascular hypertension (HRv) there is an increase in released glutamate by neurons in brainstem nuclei involved in the cardiovascular modulation, contributing to increasing pre-sympathetic neurons activity. However, it is not clear about the involvement of the astrocytes in the extracellular glutamate uptake and recycling in hypertension. This study aimed to analyze the astroglial participation in the uptake and glutamate recycling in the brainstem and hypothalamus in HRv rats. For this purpose, we performed guide-cannula implantation intracisterna magna (ICM) in SHAM and 2K1C rats (HRv model) for microinjections of: a) astrocytic glutamate transporter EAAT2 / GLT1 inhibitor [DHK (1mM)], b) astrocytic glutamine synthetase inhibitor [L-AAA (2mM)] and c) gliotoxin fluorocitrate [FCt (0.2mM)]. One group of animals (2K1C/LOS) was treated with Losartana (AT1 antagonist) by gavage at a dose of 30 mg/kg/day for 4 weeks. After femoral artery catheterization, we made cardiovascular measurements. For in vitro studies, we analyzed by western blotting the astrocytic cytoskeleton - glial fibrillary acid protein - (GFAP), the glutamate receptors (EAAT2 / GLT1 and EAAT1 / GLAST) and the enzyme glutamine synthetase (GS) protein expression. into subfornical organ (SFO), paraventricular nucleus (PVN), rostral ventrolateral brainstem (RVLM), solitary tract nucleus (NTS) and cortex (control area) regions. Our results showed that DHK, or L-AAA ICM microinjection did not change baseline MAP (mmHg) or HR (bpm) in SHAM, 2K1C or 2K1C/LOS groups. FCt ICM microinjection promoted an increase in MAP (mmHg) in the 2K1C group, but not SHAM or 2K1C/LOS. The western blotting analysis showed t in the RVLM a reduction in the GLT1 / EAAT2 and GLAST / EAAT1 transporters expression in the 2K1C. There was also a decrease in the GFAP and GS expression into NTS and RVLM of 2K1C rats. In addition, we observed a reduction in the GLAST / EAAT1 transporter expression into SFO and an increase in GFAP expression into PVN of 2K1C animals. Our results showed that inhibition of astrocytic glutamate transporters or GS on bulbar surface does not seem to be involved in the cardiovascular modulation in normotensive or 2K1C rats. However, glia appears to be involved with BP modulation in HRv. Furthermore, our in vitro studies showed HRv induce changes in the expression of different astrocytic protein in the brainstem hypothalamic nuclei involved with the cardiovascular modulation. In that regards, our studies suggest the involvement of glial cells in the modulation of blood pressure in HRv. However further studies are needed to better understand the participation of astrocytes to modulate cardiovascular function in hypertensive rats. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-11-26 2022-06-08T18:25:17Z 2022-01-24 2022-06-08T18:25:17Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufpb.br/jspui/handle/123456789/23055 |
url |
https://repositorio.ufpb.br/jspui/handle/123456789/23055 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Ciências Fisiológicas Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas UFPB |
publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Ciências Fisiológicas Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas UFPB |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da UFPB instname:Universidade Federal da Paraíba (UFPB) instacron:UFPB |
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Universidade Federal da Paraíba (UFPB) |
instacron_str |
UFPB |
institution |
UFPB |
reponame_str |
Biblioteca Digital de Teses e Dissertações da UFPB |
collection |
Biblioteca Digital de Teses e Dissertações da UFPB |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB) |
repository.mail.fl_str_mv |
diretoria@ufpb.br|| diretoria@ufpb.br |
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1801843204564189184 |