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Orientador: Katashi Okoshi / Banca: Beatriz Bojikian Matsubara / Banca: Marcia Kiyomi Koike / Resumo: A hipertensão arterial sistêmica é uma das principais causas de insuficiência cardíada (IC). No processo do desenvolvimento da hipertrofia miocárdica e a evolução pra IC, decorrente da sobrecarga pressórica, a ativação dos sistemas nervoso simpático e renina-angiotensina-aldosterona exerce papel fundamental, e a aldosterona tem sido responsabilizada por muitos desses efeitos. Diversos estudos clínicos e experimentais mostraram que o bloqueio da aldosterona atenua a remodelação ventricular na IC avançada. Considerando os efeitos adversos da aldosterona, o bloqueio de seus receptores, na fase mais precoce ao desenvolvimento da IC, poderá ser também benéfico atenuando a progressão da remodelação cardíaca. Para investigar essa questão, foram utilizados ratos espontaneamente hipertensos, com 16 meses de idade, divididos em dois grupos experimentais: controle (CTL) e tratado com espironolactona 20 mg/kg/dia (ESP) por seis meses. A pressão arterial sistólica (PAS) foi medida no início e no final do experimento. A avaliação estrutural e funcional cardíaca in vivo foi realizada por ecocardiograma. O estudo funcional in vitro foi realizado pela técnica do músculo papilar do ventrículo esquerdo (VE). A reserva contrátil foi avaliada após o aumento da concentração de cálcio extracelular, contração pós-pausa e estimulação por β-agonista isoproterenol. Para análise estrutural in vitro foram medidos os pesos do VE, ventrículo direito, átrios, pulmão e amostra de fígado, e calculada a razão peso úmido/peso seco desses órgãos. Amostras do VE foram obtidas para análise histológica, com a finalidade de medira área seccional dos cardiomiócitos (hematoxilina e eosina) e a área ocupada pelo colágeno (picrosirius red), para quantificação de hidroxiprolina e realização da técnica do RT-PCR em tempo real... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Arterial hypertension is one of the main causes of heart failure (HF). In the process of myocardial hypertrophy and HF development due to pressure overload, activation of sympathetic nervous system and renin-angiotensin system plays a fundamental role. Several clinical and experimental studies have been shown that aldosterone blockade attenuates ventricular remodeling in advanced HF. Considering the aldosterone deleterious effects, we hypothesized that the blockade of its receptors in the early phase of HF development can attenuate the progression of cardiac remodeling. To investigate this issue, 16 month-old spontaneously hypertensive rats were used. Rats were separated into two groups: control (CTL) and spironolactone treated (SPR, 20 mg/kg/day) for six months. Systolic arterial pressure (SAP) was measured at the beginning and the end of the experiment. In vivo cardiac structural and functional evaluation was performed by echocardiogram. In vitro myocardial function was analyzed in left ventricular (LV) papillary muscles under isometric contractions. Contractiel reserve was evaluated after extracellular calcium concentration increase, post-pause contractions, and β-agonist isoproterenol stimulation. In vitro structural analysis was done bay measuring LV, right ventricle, and atria weight, and the wet-to-dry weight ratio of these organs and also lung and liver samples. LV samples were stored for histological analysis (cardiomyocyte cross-sectional area and myocardial collagen fraction), measurement of hydroxyproline concentration, and quantification of gene expression of proteins related to cardiac remodeling by real-time RT-PCR. According to sample distribution, normal or non-normal, Student's t test or Mann-Whitney test was used to compare the groups. Mortality rate was analyzed by log-rank test (Kaplan Meier curve). Statistical analysis... (Complete abstract click electronic access below) / Mestre

West African immigrants appear to carry a heavier burden of hypertensive heart disease than the native-born African Americans in the United States. In this study, I used the socioecological model theory as a guide to examine the association between perceived stress, length of stay in United States, smoking status, housing conditions, and the risk of hypertensive heart disease among West African immigrants, ages 18 - 54 years in DeKalb County, Georgia. In this quantitative, cross-sectional design, self-reported data were collected from a sample of West African immigrant (N=107) in the DeKalb County of Georgia, using a demographic data/screening sheet and the Perceived Stress Scale. Multivariate logistic regression analysis was used to determine the association between hypertensive heart disease and perceived stress, smoking status, length of stay in the United States, and housing condition, having adjusted for the modifying variables age and education. Results indicated that length of stay in the United States [p =.019, Phi =.331], housing condition [p=.156, R2 =.019], smoking status [p=.050, R2 =.036] and experienced perceived stress experienced [p=.312, R2=.010] are associated with risk of developing hypertensive heart disease. There was a statistically significant association between age [p=.002] and the development of hypertensive heart disease. The result of this study can contribute to positive social change by helping public health agencies to target some of the identified risk factors for hypertensive heart disease in foreign born African American population so as to mitigate the adverse health outcomes associated with hypertensive heart disease.

Made available in DSpace on 2014-06-11T19:23:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T18:50:43Z : No. of bitstreams: 1 cezar_mdm_me_botfm.pdf: 590654 bytes, checksum: 33eb8534bd0be27d262392bb6adb637d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A hipertensão arterial sistêmica é uma das principais causas de insuficiência cardíada (IC). No processo do desenvolvimento da hipertrofia miocárdica e a evolução pra IC, decorrente da sobrecarga pressórica, a ativação dos sistemas nervoso simpático e renina-angiotensina-aldosterona exerce papel fundamental, e a aldosterona tem sido responsabilizada por muitos desses efeitos. Diversos estudos clínicos e experimentais mostraram que o bloqueio da aldosterona atenua a remodelação ventricular na IC avançada. Considerando os efeitos adversos da aldosterona, o bloqueio de seus receptores, na fase mais precoce ao desenvolvimento da IC, poderá ser também benéfico atenuando a progressão da remodelação cardíaca. Para investigar essa questão, foram utilizados ratos espontaneamente hipertensos, com 16 meses de idade, divididos em dois grupos experimentais: controle (CTL) e tratado com espironolactona 20 mg/kg/dia (ESP) por seis meses. A pressão arterial sistólica (PAS) foi medida no início e no final do experimento. A avaliação estrutural e funcional cardíaca in vivo foi realizada por ecocardiograma. O estudo funcional in vitro foi realizado pela técnica do músculo papilar do ventrículo esquerdo (VE). A reserva contrátil foi avaliada após o aumento da concentração de cálcio extracelular, contração pós-pausa e estimulação por β-agonista isoproterenol. Para análise estrutural in vitro foram medidos os pesos do VE, ventrículo direito, átrios, pulmão e amostra de fígado, e calculada a razão peso úmido/peso seco desses órgãos. Amostras do VE foram obtidas para análise histológica, com a finalidade de medira área seccional dos cardiomiócitos (hematoxilina e eosina) e a área ocupada pelo colágeno (picrosirius red), para quantificação de hidroxiprolina e realização da técnica do RT-PCR em tempo real... / Arterial hypertension is one of the main causes of heart failure (HF). In the process of myocardial hypertrophy and HF development due to pressure overload, activation of sympathetic nervous system and renin-angiotensin system plays a fundamental role. Several clinical and experimental studies have been shown that aldosterone blockade attenuates ventricular remodeling in advanced HF. Considering the aldosterone deleterious effects, we hypothesized that the blockade of its receptors in the early phase of HF development can attenuate the progression of cardiac remodeling. To investigate this issue, 16 month-old spontaneously hypertensive rats were used. Rats were separated into two groups: control (CTL) and spironolactone treated (SPR, 20 mg/kg/day) for six months. Systolic arterial pressure (SAP) was measured at the beginning and the end of the experiment. In vivo cardiac structural and functional evaluation was performed by echocardiogram. In vitro myocardial function was analyzed in left ventricular (LV) papillary muscles under isometric contractions. Contractiel reserve was evaluated after extracellular calcium concentration increase, post-pause contractions, and β-agonist isoproterenol stimulation. In vitro structural analysis was done bay measuring LV, right ventricle, and atria weight, and the wet-to-dry weight ratio of these organs and also lung and liver samples. LV samples were stored for histological analysis (cardiomyocyte cross-sectional area and myocardial collagen fraction), measurement of hydroxyproline concentration, and quantification of gene expression of proteins related to cardiac remodeling by real-time RT-PCR. According to sample distribution, normal or non-normal, Student's t test or Mann-Whitney test was used to compare the groups. Mortality rate was analyzed by log-rank test (Kaplan Meier curve). Statistical analysis... (Complete abstract click electronic access below)