Influência da deficiência de taurina no coração
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Data
2010-02-26
Autores
Pansani, Mariele Castilho [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Há evidências que pacientes com insuficiência cardíaca são deficientes em muitos micronutrientes, que representam importante papel na manutenção da homeostase do cálcio, no controle do estresse oxidativo e do metabolismo energético-protéico. Estes pacientes podem apresentar necessidades nutricionais que são diferentes daquelas de indivíduos com estado fisiológico normal. A taurina é um destes nutrientes e corresponde a 50% do total de aminoácidos livres do coração. Estudos in vivo mostraram que a deficiência de taurina está associada à cardiomiopatia, à degeneração da retina e ao retardo do crescimento. Foi realizado estudo experimental para analisar a estrutura e a função cardíaca de ratos Wistar com deficiência de taurina induzida por ß-alanina. Foram estudados 34 ratos machos, Wistar, pesando 100g, casualizados em 2 grupos: grupo controle (C), grupo deficiente em taurina (T (-)). O grupo T (-) recebeu 3% de beta-alanina na água para provocar a deficiência de taurina. Após 1 mês de tratamento os animais foram submetidos à avaliação ecocardiográfica, avaliação funcional pelo coração isolado, avaliação morfométrica, avaliação histopatológica, avaliação da atividade das metalloproteinasess e determinação da concentração de taurina no plasma e no tecido cardíaco. A deficiência de taurina por tratamento com solução de ß-alanina resultou em atrofia cardíaca verificada por afinamento da espessura da parede ventricular, menor peso seco do ventrículo esquerdo e por menores valores de área seccional dos miócitos. Outro achado em nosso estudo foi que o grupo deficiente em taurina apresentou remodelação excêntrica verificada por maior cavidade ventricular (diâmetro sistólico do ventrículo esquerdo), menor espessura da parede posterior do ventrículo esquerdo e menor valor da geometria ventricula...
Micronutrients deficiency is observed in heart failure patients. These micronutrients play important role in maintaining calcium homeostasis, controlling oxidative stress and protein/energy metabolism. Heart failure patients may present different nutritional requirements than those individuals who are healthy. Taurine is one of these nutrients and represents 50% of total free amino acids of the heart. Additionally, in vivo studies have related taurine deficiency to poor growth, cardiomyopathy and retina degeneration. One study was conducted to evaluate the structure and cardiac function of rats with or without taurine deficiency. Thirty-four male Wistar rats (body weight = 100g) were weighed and randomly assigned to 1 of 2 treatments (d 0): Control (C) or taurine-deficient (T (-)). Betaalanine in a concentration of 3% was added to water to induce taurine deficiency in T (-). On d 30, rats were individually submitted to echocardiography, functional assessment of isolated heart, morphometrical, histopathological and metalloproteinase activity evaluation. At the same day individual blood and cardiac tissue samples were collected to determine taurine concentration in plasma and heart. Rats treated T (-) presented cardiac atrophy verified by lower ventricular wall thickness, lesser dry weight of left ventricle, lower myocytes sectional area, eccentric cardiac remodeling verified by larger ventricular cavity (systolic diameter of left ventricle), lower posterior wall thickness of left ventricle and lower ventricular geometry (ratio between the measurements of posterior wall thickness and diastolic diameter of left ventricle). In addition, diastolic function was affect in T (-) rats due to diastole impairment. Rats treated T (-) showed lower velocity of A wave, higher ratio between E and A wave, and tend to have lower isovolumetric relaxation time... (Complete abstract click electronic access below)
Micronutrients deficiency is observed in heart failure patients. These micronutrients play important role in maintaining calcium homeostasis, controlling oxidative stress and protein/energy metabolism. Heart failure patients may present different nutritional requirements than those individuals who are healthy. Taurine is one of these nutrients and represents 50% of total free amino acids of the heart. Additionally, in vivo studies have related taurine deficiency to poor growth, cardiomyopathy and retina degeneration. One study was conducted to evaluate the structure and cardiac function of rats with or without taurine deficiency. Thirty-four male Wistar rats (body weight = 100g) were weighed and randomly assigned to 1 of 2 treatments (d 0): Control (C) or taurine-deficient (T (-)). Betaalanine in a concentration of 3% was added to water to induce taurine deficiency in T (-). On d 30, rats were individually submitted to echocardiography, functional assessment of isolated heart, morphometrical, histopathological and metalloproteinase activity evaluation. At the same day individual blood and cardiac tissue samples were collected to determine taurine concentration in plasma and heart. Rats treated T (-) presented cardiac atrophy verified by lower ventricular wall thickness, lesser dry weight of left ventricle, lower myocytes sectional area, eccentric cardiac remodeling verified by larger ventricular cavity (systolic diameter of left ventricle), lower posterior wall thickness of left ventricle and lower ventricular geometry (ratio between the measurements of posterior wall thickness and diastolic diameter of left ventricle). In addition, diastolic function was affect in T (-) rats due to diastole impairment. Rats treated T (-) showed lower velocity of A wave, higher ratio between E and A wave, and tend to have lower isovolumetric relaxation time... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Insuficiencia cardiaca, Coração - Doenças - Aspectos nutricionais, Cardiac remodeling, Taurine, Wistar rats
Como citar
PANSANI, Mariele Castilho. Influência da deficiência de taurina no coração. 2010. 88 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2010.