RESUMO
OBJECTIVE: To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG). METHODS: This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals. RESULTS: High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups. CONCLUSION: Vitamin C has significantly improved the patients' ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group. IRCT CODE: IRCT2016053019470N33.
Assuntos
Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Ponte de Artéria Coronária/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/prevenção & controle , Biomarcadores/sangue , Creatina Quinase Forma BB/sangue , Creatina Quinase Forma MM/sangue , Método Duplo-Cego , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Unidades de Terapia Intensiva , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Traumatismo por Reperfusão Miocárdica/sangue , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Fatores de Tempo , Resultado do Tratamento , Troponina I/sangue , Função Ventricular/efeitos dos fármacosRESUMO
Abstract Objective: To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG). Methods: This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals. Results: High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups. Conclusion: Vitamin C has significantly improved the patients' ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group. IRCT code: IRCT2016053019470N33
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Ácido Ascórbico/administração & dosagem , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Ponte de Artéria Coronária/métodos , Antioxidantes/administração & dosagem , Arritmias Cardíacas/prevenção & controle , Fatores de Tempo , Biomarcadores/sangue , Traumatismo por Reperfusão Miocárdica/sangue , Método Duplo-Cego , Reprodutibilidade dos Testes , Função Ventricular/efeitos dos fármacos , Resultado do Tratamento , Estatísticas não Paramétricas , Troponina I/sangue , Creatina Quinase Forma BB/sangue , Creatina Quinase Forma MM/sangue , Hemodinâmica/efeitos dos fármacos , Unidades de Terapia Intensiva , L-Lactato Desidrogenase/sangueRESUMO
Abstract Background: Although the beneficial effects of resistance training (RT) on the cardiovascular system are well established, few studies have investigated the effects of the chronic growth hormone (GH) administration on cardiac remodeling during an RT program. Objective: To evaluate the effects of GH on the morphological features of cardiac remodeling and Ca2+ transport gene expression in rats submitted to RT. Methods: Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH, RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30 days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3 bouts/wk) for 30 consecutive days. After the experimental period, the following variables were analyzed: final body weight (FBW), left ventricular weight (LVW), LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction, creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a, phospholamban (PLB) and ryanodine (RyR). Results: There was no significant (p > 0.05) difference among groups for FBW, LVW, LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The RT group showed a significant (p < 0.05) increase in collagen fraction compared to the other groups. Additionally, the trained groups (RT and RTGH) had greater CK-MB levels compared to the untrained groups (CT and GH). Conclusion: GH may attenuate the negative effects of RT on cardiac remodeling by counteracting the increased collagen synthesis, without affecting the gene expression that regulates cardiac Ca2+ transport.
Resumo Fundamento: Apesar de os efeitos benéficos do treinamento resistido (TR) sobre o sistema cardiovascular estarem bem estabelecidos, poucos estudos têm investigado os efeitos crônicos da administração de hormônio do crescimento (GH) sobre a remodelação cardíaca durante um programa de TR. Objetivo: avaliar os efeitos do GH sobre a remodelação cardíaca em suas características morfológicas e na expressão dos genes do trânsito de Ca2+ em ratos submetidos ao TR. Métodos: Ratos Wistar machos foram divididos em 4 grupos (n = 7 por grupo): controle (CT), GH, TR e TR com GH (TRGH). A dose de GH foi de 0,2 UI/kg, a cada dois dias, por 30 dias. O modelo de TR utilizado foi o salto vertical em água (4 séries de 10 saltos, 3 vezes/semana) durante 30 dias consecutivos. Após o período experimental, as seguintes variáveis foram analisadas: peso corporal final (PCF), peso do ventrículo esquerdo (PVE), razão PVE/PCF, área seccional de cardiomiócitos (ASC), fração de colágeno, creatina quinase fração músculo-cérebro (CK-MB) e expressão gênica de SERCA2a, fosfolambam (PLB) e rianodina (RyR). Resultados: Não houve diferença significativa (p > 0,05) entre os grupos para PCF, PVE, razão PVE/PCF, ASC, e expressão gênica de SERCA2a, PLB e RyR. O grupo TR mostrou um significativo aumento (p < 0,05) da fração de colágeno em comparação aos outros. Além disso, os grupos treinados (TR e TRGH) apresentaram maiores níveis de CK-MB em comparação aos não treinados (CT e GH). Conclusão: Esses resultados indicam que o GH pode atenuar os efeitos negativos do TR na remodelação cardíaca por contrabalançar o aumento da síntese de colágeno, sem afetar a expressão de genes que regulam o trânsito de Ca2+ cardíaco.
Assuntos
Animais , Masculino , Hormônio do Crescimento/farmacologia , Treinamento Resistido/métodos , Remodelação Ventricular/efeitos dos fármacos , Peso Corporal , Proteínas de Ligação ao Cálcio/análise , Cálcio/metabolismo , Colágeno/análise , Colágeno/efeitos dos fármacos , Creatina Quinase Forma BB/sangue , Creatina Quinase Forma BB/efeitos dos fármacos , Expressão Gênica , Ventrículos do Coração/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Tamanho do Órgão , Reação em Cadeia da Polimerase , Ratos Wistar , Rianodina/análise , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/análise , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/efeitos dos fármacos , Fatores de Tempo , Remodelação Ventricular/genéticaRESUMO
BACKGROUND: Although the beneficial effects of resistance training (RT) on the cardiovascular system are well established, few studies have investigated the effects of the chronic growth hormone (GH) administration on cardiac remodeling during an RT program. OBJECTIVE: To evaluate the effects of GH on the morphological features of cardiac remodeling and Ca2+ transport gene expression in rats submitted to RT. METHODS: Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH, RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30 days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3 bouts/wk) for 30 consecutive days. After the experimental period, the following variables were analyzed: final body weight (FBW), left ventricular weight (LVW), LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction, creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a, phospholamban (PLB) and ryanodine (RyR). RESULTS: There was no significant (p > 0.05) difference among groups for FBW, LVW, LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The RT group showed a significant (p < 0.05) increase in collagen fraction compared to the other groups. Additionally, the trained groups (RT and RTGH) had greater CK-MB levels compared to the untrained groups (CT and GH). CONCLUSION: GH may attenuate the negative effects of RT on cardiac remodeling by counteracting the increased collagen synthesis, without affecting the gene expression that regulates cardiac Ca2+ transport.