BackgroundThere is growing interest in sex differences and RAS components. However, whether gender influences cardiac angiotensin I-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity is still unknown. In the present work, we determined the relationship between ACE and ACE2 activity, left ventricular function and gender in spontaneously hypertensive rats (SHRs).Methodology / Principal FindingsTwelve-week-old female (F) and male (M) SHRs were divided into 2 experimental groups (n = 7 in each group): sham (S) and gonadectomized (G). Fifty days after gonadectomy, we measured positive and negative first derivatives (dP/dt maximum left ventricle (LV) and dP/dt minimum LV, respectively), hypertrophy (morphometric analysis) and ACE and ACE2 catalytic activity (fluorimetrically). Expression of calcium handling proteins was measured by western blot. Male rats exhibited higher cardiac ACE and ACE2 activity as well as hypertrophy compared to female rats. Orchiectomy decreased the activity of these enzymes and hypertrophy, while ovariectomy increased hypertrophy and ACE2, but did not change ACE activity. For cardiac function, the male sham group had a lower +dP/dt than the female sham group. After gonadectomy, the +dP/dt increased in males and reduced in females. The male sham group had a lower -dP/dt than the female group. After gonadectomy, the -dP/dt increased in the male and decreased in the female groups when compared to the sham group. No difference was observed among the groups in SERCA2a protein expression. Gonadectomy increased protein expression of PLB (phospholamban) and the PLB to SERCA2a ratio in female rats, but did not change in male rats.ConclusionOvariectomy leads to increased cardiac hypertrophy, ACE2 activity, PLB expression and PLB to SERCA2a ratio, and worsening of hemodynamic variables, whereas in males the removal of testosterone has the opposite effects on RAS components.

Objective: The identification of populational levels of maximum oxygen uptake (VO 2max ) is an aid to studies that propose to relate physical fitness to cardiovascular risk, and also for prescribing exercise and analyzing the effects of training. To date, there is no information with which this parameter can be classified in samples of adolescents from the Brazilian population. This study is, therefore, the first to propose the determination of mean VO 2max levels in a sample of the Brazilian population.Methods: A sample of 380 schoolchildren (177 boys and 203 girls, aged 10 to 14 years) was selected at random from public schools in Vitória, ES. After anthropometric assessment they underwent cardiopulmonary exercise testing, VO 2max was measured directly and results were classified according to quintiles calculated from the study sample.Results: The mean VO 2max values observed ranged from 42.95 to 49.55 mL.kg -1 .min -1 for boys and from 36.76 to 38.29 mL.kg -1 .min -1 for girls.Conclusions: This paper proposes mean VO 2max ranges as a classification parameter for cardiorespiratory fitness, in addition to contributing to a definition of normal values for the Brazilian population. This classification will also be of use for establishing cutoff points in future studies.J Pediatr (Rio J). 2006;82(6):426-30: Maximum oxygen uptake, adolescents, aerobic fitness, cardiopulmonary exercise testing. ResumoObjetivo: A identificação de valores populacionais do consumo máximo de oxigênio (VO 2 máx) auxilia nos estudos que se propõem a relacionar a aptidão física ao risco cardiovascular, bem como na prescrição do exercício e na análise do efeito do treinamento. Em amostras de adolescentes da população brasileira, ainda não existem informações para classificação desse parâmetro. Portanto, a proposta inédita deste estudo foi de determinar os valores médios de VO 2 máx de uma amostra da população brasileira.Métodos: Foi selecionada aleatoriamente uma amostra de 380 escolares (177 meninos e 203 meninas) da rede pública de Vitória (ES), com idade de 10 a 14 anos. Após avaliação antropométrica, foram submetidos a teste cardiopulmonar para medida direta do VO 2 máx, cujos valores foram classificados de acordo com o quintil calculado a partir da amostra estudada.Resultados: Os valores médios de VO 2 máx encontrados para os meninos foram de 42,95 a 49,55 mL.kg -1 .min -1 e, nas meninas, entre 36,76 e 38,29 mL.kg -1 .min -1 .Conclusões: O presente trabalho propõe faixas de valores médios de VO 2 máx como parâmetro para classificação de aptidão cardiorrespiratória, além de contribuir para a definição dos valores de normalidade da população brasileira. Essa classificação auxilia também no estabelecimento de pontos de corte para estudos posteriores. O sedentarismo é um problema crescente que tem atingido um número cada vez maior de crianças e adolescentes. Autores relatam que há uma tendência entre os adolescentes de se envolverem menos nas atividades de educação física escolar e em atividades vigorosas e de aumentarem o tempo d...

ObjectivesTo correlate cardiovascular risk factors (e.g., hypertension, obesity, hypercholesterolemia, hypertriglyceridemia, hyperglycemia, sedentariness) in childhood and adolescence with the occurrence of cardiovascular disease.SourcesA systematic review of books and selected articles from PubMed, SciELO and Cochrane from 1992 to 2012.Summary of findingsRisk factors for atherosclerosis are present in childhood, although cardiovascular disease arises during adulthood. This article presents the main studies that describe the importance of investigating the risk factors for cardiovascular diseases in childhood and their associations. Significant rates of hypertension, obesity, dyslipidemia, and sedentariness occur in children and adolescents. Blood pressure needs to be measured in childhood. An increase in arterial blood pressure in young people predicts hypertension in adulthood. The death rate from cardiovascular disease is lowest in children with lower cholesterol levels and in individuals who exercise regularly. In addition, there is a high prevalence of sedentariness in children and adolescents.ConclusionsStudies involving the analysis of cardiovascular risk factors should always report the prevalence of these factors and their correlations during childhood because these factors are indispensable for identifying an at-risk population. The identification of risk factors in asymptomatic children could contribute to a decrease in cardiovascular disease, preventing such diseases as hypertension, obesity, and dyslipidemia from becoming the epidemics of this century.

RYGB and SG procedures demonstrated a similar impact on adipokine levels in women 1 year post-surgery. Both techniques may improve the course of chronic diseases and the state of inflammation associated with obesity.

The present study was designed to determine relaxation in response to 17ß-estradiol by isolated perfused hearts from intact normotensive male and female rats as well as the contribution of endothelium and its relaxing factors to this action. Baseline coronary perfusion pressure was determined and the vasoactive effects of 17ß-estradiol (10 µM) were assessed by in bolus administration before and after endothelium denudation by infusion of 0.25 µM sodium deoxycholate or perfusion with 100 µM L-NAME, 2.8 µM indomethacin, 0.75 µM clotrimazole, 100 µM L-NAME plus 2.8 µM indomethacin, and 100 µM L-NAME plus 0.75 µM clotrimazole. Baseline coronary perfusion pressure differed significantly between males (84 ± 2 mmHg, N = 61) and females (102 ± 2 mmHg, N = 61). Bolus injection of 10 µM 17ß-estradiol elicited a transient relaxing response in all groups, which was greater in coronary beds from females. For both sexes, the relaxing response to 17ß-estradiol was at least in part endothelium-dependent. In the presence of the nitric oxide synthase inhibitor L-NAME, the relaxing response to 17ß-estradiol was reduced only in females. Nevertheless, in the presence of indomethacin, a cyclooxygenase inhibitor, or clotrimazole, a cytochrome P450 inhibitor, the 17ß-estradiol response was significantly reduced in both groups. In addition, combined treatment with L-NAME plus indomethacin or L-NAME plus clotrimazole also reduced the 17ß-estradiol response in both groups. These results indicate the importance of prostacyclin and endothelium-derived hyperpolarizing factor in the relaxing response to 17ß-estradiol. 17ß-estradiol-induced relaxation may play an important role in the regulation of coronary tone and this may be one of the reasons why estrogen replacement therapy reduces the risk of coronary heart disease in postmenopausal women.