Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos

Detalhes bibliográficos
Autor(a) principal: Baldo, Marcelo Perim
Data de Publicação: 2008
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/10/7914
Resumo: Background. The granulocyte colony-stimulating factor (G-CSF) mobilizes bone marrow stem cells and in the case of a cardiac pathophysiological event, such as acute myocardial infarction, they would repair the injured myocardium. Improvement in cardiac function, decrease in infarction size and mortality were related to G-CSF treatment. With the knowledge’s evolution in this area, a direct effect on myocardium was evidenced as responsible to some beneficial effects, and that cardiac regeneration had a small contribution to this effects. Aims. In agreement with this data, we propose to evaluate the effects of pretreatment with G-CSF on acute phase of myocardial infarction, and its impacts in the cardiac remodeling process and to heart failure evolution. Methods. Male Wistar rats (180-240g) were randomized to receive G-CSF (50µg/kg, sc) or vehicle, at 7, 3 and 1 days before surgery. Myocardial infarction was induced by permanent occlusion of left descending coronary artery and the infarction size was measured through tripheniltetrazolium chloride (24 hours) or by infarction scar area (15 days). A group of animals were submitted to false-surgery and used as control (Sham). Protein expression was made immediately before myocardial infarction induction by Western blot, in a sample of the left ventricle. To evaluate the postinfarction ventricular arrhythmias, the animals were anesthetized with pentobarbital (60mg/kg, ip) and the electrocardiogram was monitored by 30 minutes after occlusion. The number of premature ventricular complex, incidence and duration of ventricular tachycardia (VT) and the incidence of ventricular fibrillation (VF) were computed. Hemodynamic measurements were performed 15 days after myocardial infarction through ventricular catheterization under ketamine (70mg/kg) and xilazine (10mg/kg) anesthesia. After ventricular catheterization, analysis of left ventricular stiffness was made by pressure-volume curve (P-V). Results. Myocardial infarction size measured 24 hours after coronary occlusion was decreased by G-CSF pretreatment (35.8±2.8 vs. 43.7±2.1 IM; p<0.05). Moreover, 15 days after coronary occlusion, the myocardial infarction was reduced in the IM-GCSF group as compare to IM group (27,2±2,2% vs. 35,9±1,4%, p<0,05). The treatment with G-CSF increase the protein expression of Bcl-2 (8.8±0.9 vs. 5.2±0.6 in IM group, p<0.05), Bcl-xL (5.6±0.8 vs. 3±0.2 in IM group, p<0.05), but doesn’t change Bax expression (5.9±1 vs. 5.5±1.2 in IM group, p>0.05). In the first 24 hours after infarction, mortality was significantly reduced by G-CSF pretreatment (26% vs. 47%, p<0.05), being the reduction more prominent at the first 30 minutes after occlusion (11% vs. 27.6%, p<0.05). The number of events (7±2 vs 29±6, p<0.05) and the duration (13±4 s vs. 43±9 s, p<0.05) of VT were reduced in the animals of IM-GCSF group, as well as the incidence of VF (10% vs 69%, p<0.05). IM group presents less ventricular stiffness as compared to other groups in a initial phase (k=19.9±2.5 vs. k=41±5 in IM-GCSF group and k=42.8±3.5 in Sham group, p<0.05), but at high pressure, the ventricular stiffness in IM only differs from IMGCSF group (k=2.52±0.2, IM; k=3.35±0.2, IM-GCSF; k=3.02±0.7, Sham; p<0.05). Conclusions. The pretreatment with G-CSF was effective in reducing myocardial infarction size evaluated soon after coronary occlusion and this difference was maintained throughout 15 days after occlusion. This result is due to an increase in expression of antiapoptotical factors, reducing the ischemic injury in the initial phase of myocardial infarction. Moreover, the increase in connexin43 expression in pretreated group seems to be responsible for the decrease in ventricular arrhythmias, leading to an important reduction in mortality rate soon after myocardial infarction. All of these results seem to contribute to hemodynamic preservation found 15 days after coronary occlusion in animals that received G-CSF.
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spelling Mill, José GeraldoBaldo, Marcelo PerimCarvalho, Antônio Carlos Campos deMeyrelles, Silvana dos Santos2018-08-01T22:58:30Z2018-08-012018-08-01T22:58:30Z2008-05-16Background. The granulocyte colony-stimulating factor (G-CSF) mobilizes bone marrow stem cells and in the case of a cardiac pathophysiological event, such as acute myocardial infarction, they would repair the injured myocardium. Improvement in cardiac function, decrease in infarction size and mortality were related to G-CSF treatment. With the knowledge’s evolution in this area, a direct effect on myocardium was evidenced as responsible to some beneficial effects, and that cardiac regeneration had a small contribution to this effects. Aims. In agreement with this data, we propose to evaluate the effects of pretreatment with G-CSF on acute phase of myocardial infarction, and its impacts in the cardiac remodeling process and to heart failure evolution. Methods. Male Wistar rats (180-240g) were randomized to receive G-CSF (50µg/kg, sc) or vehicle, at 7, 3 and 1 days before surgery. Myocardial infarction was induced by permanent occlusion of left descending coronary artery and the infarction size was measured through tripheniltetrazolium chloride (24 hours) or by infarction scar area (15 days). A group of animals were submitted to false-surgery and used as control (Sham). Protein expression was made immediately before myocardial infarction induction by Western blot, in a sample of the left ventricle. To evaluate the postinfarction ventricular arrhythmias, the animals were anesthetized with pentobarbital (60mg/kg, ip) and the electrocardiogram was monitored by 30 minutes after occlusion. The number of premature ventricular complex, incidence and duration of ventricular tachycardia (VT) and the incidence of ventricular fibrillation (VF) were computed. Hemodynamic measurements were performed 15 days after myocardial infarction through ventricular catheterization under ketamine (70mg/kg) and xilazine (10mg/kg) anesthesia. After ventricular catheterization, analysis of left ventricular stiffness was made by pressure-volume curve (P-V). Results. Myocardial infarction size measured 24 hours after coronary occlusion was decreased by G-CSF pretreatment (35.8±2.8 vs. 43.7±2.1 IM; p<0.05). Moreover, 15 days after coronary occlusion, the myocardial infarction was reduced in the IM-GCSF group as compare to IM group (27,2±2,2% vs. 35,9±1,4%, p<0,05). The treatment with G-CSF increase the protein expression of Bcl-2 (8.8±0.9 vs. 5.2±0.6 in IM group, p<0.05), Bcl-xL (5.6±0.8 vs. 3±0.2 in IM group, p<0.05), but doesn’t change Bax expression (5.9±1 vs. 5.5±1.2 in IM group, p>0.05). In the first 24 hours after infarction, mortality was significantly reduced by G-CSF pretreatment (26% vs. 47%, p<0.05), being the reduction more prominent at the first 30 minutes after occlusion (11% vs. 27.6%, p<0.05). The number of events (7±2 vs 29±6, p<0.05) and the duration (13±4 s vs. 43±9 s, p<0.05) of VT were reduced in the animals of IM-GCSF group, as well as the incidence of VF (10% vs 69%, p<0.05). IM group presents less ventricular stiffness as compared to other groups in a initial phase (k=19.9±2.5 vs. k=41±5 in IM-GCSF group and k=42.8±3.5 in Sham group, p<0.05), but at high pressure, the ventricular stiffness in IM only differs from IMGCSF group (k=2.52±0.2, IM; k=3.35±0.2, IM-GCSF; k=3.02±0.7, Sham; p<0.05). Conclusions. The pretreatment with G-CSF was effective in reducing myocardial infarction size evaluated soon after coronary occlusion and this difference was maintained throughout 15 days after occlusion. This result is due to an increase in expression of antiapoptotical factors, reducing the ischemic injury in the initial phase of myocardial infarction. Moreover, the increase in connexin43 expression in pretreated group seems to be responsible for the decrease in ventricular arrhythmias, leading to an important reduction in mortality rate soon after myocardial infarction. All of these results seem to contribute to hemodynamic preservation found 15 days after coronary occlusion in animals that received G-CSF.Introdução. Estudos na literatura mostram que o fator estimulante de colônia de granulócitos (G-CSF) é capaz mobilizar células-tronco provenientes da medula óssea que diante de um evento fisiopatológico no coração, como por exemplo o infarto agudo do miocárdio, fariam o reparo do miocárdio perdido. Efeitos como a melhora da função cardíaca, redução do infarto e da mortalidade foram relacionados ao tratamento com G-CSF. Com a evolução do conhecimento na área, foi evidenciado um efeito direto sobre o miocárdio, como sendo responsável por todos os efeitos benéficos, e que as células mobilizadas pelo G-CSF não contribuiriam de forma significativa pelos benefícios. Objetivos. Diante dessas informações, nós objetivamos avaliar os efeitos do pré-tratamento com G-CSF sobre a fase aguda do infarto do miocárdio, e suas repercussões no remodelamento e progressão para a insuficiência cardíaca. Metodologia. Ratos Wistar (180-240g) foram randomizados para receber G-CSF (50Ng/kg, sc) (IM-GCSF) ou placebo (IM), aplicados 7, 3 e 1 dias antes da cirurgia. O infarto foi realizado através da oclusão permanente da artéria coronária descendente anterior esquerda e a extensão do infarto foi determinada através da área corada com trifeniltetrazólio (24 horas) ou pela área da cicatriz (15 dias). Um grupo de animais foi submetido à cirurgia fictícia para ser utilizado como controle (Sham). A medida da expressão protéica de Bcl-2, Bcl-xL e Bax foram realizadas imediatamente antes da indução do infarto por Western blot, utilizando amostras de ventrículo esquerdo. Para avaliar as arritmias ventriculares após o infarto, os animais foram anestesiados com pentobarbital (60mg/kg, ip) e o eletrocardiograma foi monitorado por 30 minutos após a oclusão. O número de extrassístoles ventriculares, incidência e duração de taquicardias ventriculares (TV) e a incidência de fibriliação ventricular (FV) foram computados. Medidas hemodinâmicas foram realizadas 15 dias após o infarto através do cateterismo ventricular sob anestesia de quetamina (70mg/kg) e xilazina (10mg/kg). Após o cateterismo ventricular, a avaliação da rigidez da câmara ventricular esquerda foi feita através da análise da curva pressão-volume (P-V). Resultados. A extensão do infarto medida 24 horas após a oclusão foi reduzida pelo pré-tratamento com G-CSF (35,8±2,8 vs. 43,7±2,1 IM; p<0,05). Da mesma forma, 15 dias após a oclusão, a extensão do infarto se apresentou reduzida no grupo IM-GCSF comparada ao grupo IM (27,2±2,2% vs. 35,9±1,4%, p<0,05). O pré-tratamento com G-CSF aumentou a expressão protéica de Bcl-2 (8,8±0,9 vs. 5,2±0,6 no grupo IM, p<0,05), Bcl-xL (5,6±0,8 vs. 3±0,2 no grupo IM, p<0,05), mas não alterou os níveis de expressão de Bax (5,9±1 vs. 5,5±1,2 no grupo IM, p>0,05). A mortalidade nas primeiras 24 horas após o infarto foi reduzida significativamente diante do pré-tratamento com G-CSF (26% vs. 47%, p<0,05), sendo a redução mais pronunciada nos primeiros 30 minutos seguidos à oclusão (11% vs. 27,6%, p<0,05). Tanto o número de eventos (7±2 vs 29±6, p<0,05) quanto a duração (13±4 seg vs. 43±9 seg, p<0,05) das TV foram reduzidos nos animais do grupo IM-GCSF, assim como a incidência de FV (10% vs 69%, p<0,05). O grupo IM apresentou menor rigidez ventricular quando comparado a outros grupos na fase inicial (k=19,9±2,5 vs. k=41±5 no grupo IM-GCSF e k=42,8±3,5 no grupo Sham, p<0,05), mas sob altas pressões, a rigidez ventricular no grupo IM difere somente do grupo IM-GCSF (k=2,52±0,2, IM; k=3,35±0,2, IM-GCSF; k=3,02±0,7, Sham; p<0,05). Conclusão. O pré-tratamento com G-CSF foi efetivo em reduzir a extensão do infarto avaliada 24 horas após a oclusão, e essa diferença se manteve ao longo dos 15 dias após a oclusão, mesmo diante da interrupção do tratamento. Esse resultado pode ser devido ao aumento na expressão de fatores anti-apoptóticos, reduzindo a injúria isquêmica na fase inicial do infarto. Além disto, o aumento na expressão de conexina43 no grupo pré-tratado pode estar envolvido na redução das arritmias ventriculares, levando a importante redução da mortalidade precocemente ao infarto. Todos estes resultados parecem contribuir para a preservação da função hemodinâmica encontrada 15 dias após o infarto nos animais que receberam G-CSF.Texthttp://repositorio.ufes.br/handle/10/7914porUniversidade Federal do Espírito SantoMestrado em Ciências FisiológicasPrograma de Pós-Graduação em Ciências FisiológicasUFESBRCentro de Ciências da SaúdeMyocardial infarctionApoptosisVentricular arrhythmiasRemodelingMortalityG-CSFInfarto do miocárdioApoptoseArritmias ventricularesRemodelamentoMortalidadeFisiologia612Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratosinfo: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_2997_Dissertação Marcelo Perim Baldo.pdfapplication/pdf1551697http://repositorio.ufes.br/bitstreams/ef0a1ecd-20b7-4183-8854-9a6183076a3b/download974b1236fc3e2f32679adea569af6619MD5110/79142024-07-16 17:03:54.596oai:repositorio.ufes.br:10/7914http://repositorio.ufes.brRepositório InstitucionalPUBhttp://repositorio.ufes.br/oai/requestopendoar:21082024-10-15T17:53:24.227068Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) - Universidade Federal do Espírito Santo (UFES)false
dc.title.none.fl_str_mv Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
title Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
spellingShingle Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
Baldo, Marcelo Perim
Myocardial infarction
Apoptosis
Ventricular arrhythmias
Remodeling
Mortality
G-CSF
Infarto do miocárdio
Apoptose
Arritmias ventriculares
Remodelamento
Mortalidade
Fisiologia
612
title_short Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
title_full Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
title_fullStr Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
title_full_unstemmed Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
title_sort Efeitos do pré-tratamento com o fator estimulante de colônia de granulócitos (G-CSF) sobre o desenvolvimento do infarto do miocárdio em ratos
author Baldo, Marcelo Perim
author_facet Baldo, Marcelo Perim
author_role author
dc.contributor.advisor1.fl_str_mv Mill, José Geraldo
dc.contributor.author.fl_str_mv Baldo, Marcelo Perim
dc.contributor.referee1.fl_str_mv Carvalho, Antônio Carlos Campos de
dc.contributor.referee2.fl_str_mv Meyrelles, Silvana dos Santos
contributor_str_mv Mill, José Geraldo
Carvalho, Antônio Carlos Campos de
Meyrelles, Silvana dos Santos
dc.subject.eng.fl_str_mv Myocardial infarction
Apoptosis
Ventricular arrhythmias
Remodeling
Mortality
topic Myocardial infarction
Apoptosis
Ventricular arrhythmias
Remodeling
Mortality
G-CSF
Infarto do miocárdio
Apoptose
Arritmias ventriculares
Remodelamento
Mortalidade
Fisiologia
612
dc.subject.por.fl_str_mv G-CSF
Infarto do miocárdio
Apoptose
Arritmias ventriculares
Remodelamento
Mortalidade
dc.subject.cnpq.fl_str_mv Fisiologia
dc.subject.udc.none.fl_str_mv 612
description Background. The granulocyte colony-stimulating factor (G-CSF) mobilizes bone marrow stem cells and in the case of a cardiac pathophysiological event, such as acute myocardial infarction, they would repair the injured myocardium. Improvement in cardiac function, decrease in infarction size and mortality were related to G-CSF treatment. With the knowledge’s evolution in this area, a direct effect on myocardium was evidenced as responsible to some beneficial effects, and that cardiac regeneration had a small contribution to this effects. Aims. In agreement with this data, we propose to evaluate the effects of pretreatment with G-CSF on acute phase of myocardial infarction, and its impacts in the cardiac remodeling process and to heart failure evolution. Methods. Male Wistar rats (180-240g) were randomized to receive G-CSF (50µg/kg, sc) or vehicle, at 7, 3 and 1 days before surgery. Myocardial infarction was induced by permanent occlusion of left descending coronary artery and the infarction size was measured through tripheniltetrazolium chloride (24 hours) or by infarction scar area (15 days). A group of animals were submitted to false-surgery and used as control (Sham). Protein expression was made immediately before myocardial infarction induction by Western blot, in a sample of the left ventricle. To evaluate the postinfarction ventricular arrhythmias, the animals were anesthetized with pentobarbital (60mg/kg, ip) and the electrocardiogram was monitored by 30 minutes after occlusion. The number of premature ventricular complex, incidence and duration of ventricular tachycardia (VT) and the incidence of ventricular fibrillation (VF) were computed. Hemodynamic measurements were performed 15 days after myocardial infarction through ventricular catheterization under ketamine (70mg/kg) and xilazine (10mg/kg) anesthesia. After ventricular catheterization, analysis of left ventricular stiffness was made by pressure-volume curve (P-V). Results. Myocardial infarction size measured 24 hours after coronary occlusion was decreased by G-CSF pretreatment (35.8±2.8 vs. 43.7±2.1 IM; p<0.05). Moreover, 15 days after coronary occlusion, the myocardial infarction was reduced in the IM-GCSF group as compare to IM group (27,2±2,2% vs. 35,9±1,4%, p<0,05). The treatment with G-CSF increase the protein expression of Bcl-2 (8.8±0.9 vs. 5.2±0.6 in IM group, p<0.05), Bcl-xL (5.6±0.8 vs. 3±0.2 in IM group, p<0.05), but doesn’t change Bax expression (5.9±1 vs. 5.5±1.2 in IM group, p>0.05). In the first 24 hours after infarction, mortality was significantly reduced by G-CSF pretreatment (26% vs. 47%, p<0.05), being the reduction more prominent at the first 30 minutes after occlusion (11% vs. 27.6%, p<0.05). The number of events (7±2 vs 29±6, p<0.05) and the duration (13±4 s vs. 43±9 s, p<0.05) of VT were reduced in the animals of IM-GCSF group, as well as the incidence of VF (10% vs 69%, p<0.05). IM group presents less ventricular stiffness as compared to other groups in a initial phase (k=19.9±2.5 vs. k=41±5 in IM-GCSF group and k=42.8±3.5 in Sham group, p<0.05), but at high pressure, the ventricular stiffness in IM only differs from IMGCSF group (k=2.52±0.2, IM; k=3.35±0.2, IM-GCSF; k=3.02±0.7, Sham; p<0.05). Conclusions. The pretreatment with G-CSF was effective in reducing myocardial infarction size evaluated soon after coronary occlusion and this difference was maintained throughout 15 days after occlusion. This result is due to an increase in expression of antiapoptotical factors, reducing the ischemic injury in the initial phase of myocardial infarction. Moreover, the increase in connexin43 expression in pretreated group seems to be responsible for the decrease in ventricular arrhythmias, leading to an important reduction in mortality rate soon after myocardial infarction. All of these results seem to contribute to hemodynamic preservation found 15 days after coronary occlusion in animals that received G-CSF.
publishDate 2008
dc.date.issued.fl_str_mv 2008-05-16
dc.date.accessioned.fl_str_mv 2018-08-01T22:58:30Z
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2018-08-01T22:58:30Z
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Mestrado em Ciências Fisiológicas
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publisher.none.fl_str_mv Universidade Federal do Espírito Santo
Mestrado em Ciências Fisiológicas
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