Effects of chronic stress and high-fat diet on metabolic and nutritional parameters in Wistar rats Efeitos do estresse crônico e da dieta rica em gordura sobre os parâmetros metabólicos e nutricionais em ratos Wistar

ABSTRACT Objective: The aim of this study was assess the role of chronic stress on the metabolic and nutritional profile of rats exposed to a high-fat diet. Materials and methods: Thirty-day-old male Wistar rats (70-100 g) were distributed into four groups: normal-diet (NC), chronic stress (St), high-fat diet (HD), and chronic stress/high-fat diet (HD/St). Stress consisted at immobilization during 15 weeks, 5 times per week, 1h per day; and exposure to the high-fat diet lasted 15 weeks. Nutritional and metabolic parameters were assessed. The level of significance was 5%. Results: The HD group had final body weight, total fat, as well as insulin and leptin increased, and they were insulin resistant. The St and HD/St had arterial hypertension and increased levels of corticosterone. Stress blocked the effects of the high-fat diet. Conclusion: Chronic stress prevented the appearance of obesity. Our results help to clarify the mechanisms involved in metabolic and nutritional dysfunction, and contribute to clinical cases linked to stress and high-fat diet. Arq Bras Endocrinol Metab. 2013;57(8):642-9 Keywords Chronic stress; high-fat diet; calorie intake and food intake RESUMO Objetivo: Avaliar o papel do estresse crônico sobre parâmetros metabólicos e nutricionais de ratos expostos à dieta rica em gordura. Materiais e métodos: Ratos Wistar machos (30 dias de idade/70-100 g) foram distribuídos em quatro grupos: dieta-normal (NC), estresse crônico (St), dieta rica em gordura (HD) e estresse crônico/dieta rica em gordura (HD/St). O estresse consistiu em imobilização durante 15 semanas, 5 vezes por semana 1h por dia e a dieta rica em gordura foi oferecida por 15 semanas. Parâmetros nutricionais e metabólicos foram avaliados. O nível de significância foi de 5%. Resultados: HD tiveram peso corpóreo, gordura total e níveis de insulina e leptina aumentados e foram resistentes à insulina. Os grupos St e HD/St manifestaram hipertensão e níveis séricos de corticosterona elevados. O estresse bloqueou os efeitos da dieta. Conclusão: O estresse impediu o surgimento dela. Nossos resultados ajudam compreender os mecanismos envolvidos na disfunção metabólica e nutricional e contribuem para casos clínicos de estresse e dietas ricas em gorduras. Arq Bras Endocrinol Metab. 2013;57(8):642-9 Descritores Estresse crônico; dieta rica em gordura; consumo calórico e metabolism

Endobronchial myxoma: Case report

INTRODUCTION: Pulmonary myxoma is an extremely rare benign neoplasm. It is mostly parenchymal but may occasionally occur within the tracheobronchial tree. There are very few reports of endobronchial myxoma. CASE REPORT: We describe a case of endobronchial myxoma in a 40-year-old female patient with a history of asthma and repeated right-sided pneumonia. Thoracic computed tomography (CT) showed medium lobe atelectasis. Fiber optic bronchoscopy revealed a polypoid, well-circumscribed tumor, causing total obstruction of the medium lobe bronchus. Biopsy of the mass was non-diagnostic. Further study included a positron emission tomography (PET) which demonstrated low metabolic activity of the tumor and no evidence of neoplasia in other location. The patient was submitted to a medium lobectomy and microscopic examination of the tumor revealed myxoid stroma with lobulated pattern, elongated and stellate cells, compatible with myxoma. CONCLUSION: Pulmonary myxoma is extraordinary rare and endobronchial location is very few reported in medical literature

Assessment of inotropic and vasodilating effects of milrinone lactate in patients with dilated cardiomyopathy and severe heart failure

OBJECTIVE: To assess the hemodynamic and vasodilating effects of milrinone lactate (ML) in patients with dilated cardiomyopathy (DCM) and New York Heart Association (NYHA) class III and IV heart failure. METHODS: Twenty patients with DCM and NYHA class III and IV heart failure were studied. The hemodynamic and vasodilating effects of ML, administered intravenously, were evaluated. The following variables were compared before and during drug infusion: cardiac output (CO) and cardiac index (CI); pulmonary capillary wedge pressure (PCWP); mean aortic pressure (MAP); mean pulmonary artery pressure (MPAP); mean right atrial pressure (MRAP); left ventricular systolic and end-diastolic pressures (LVSP and LVEDP, respectively); peak rate of left ventricular pressure rise (dP/dt); systemic vascular resistance (SVR); pulmonary vascular resistance (PVR); and heart rate (HR). RESULTS: All patients showed a significant improvement of the analysed parameters of cardiac performance with an increase of CO and CI; a significant improvement in myocardial contractility (dP/dt) and reduction of the LVEDP; PCWP; PAP; MAP; MRAP; SVR; PVR. Were observed no significant increase in HR occurred. CONCLUSION: Milrinone lactate is an inotropic dilating drug that, when administered intravenously, has beneficial effects on cardiac performance and myocardial contractility. It also promotes reduction of SVR and PVR in patients with DCM and NYHA class III and IV of heart failure

Effects of protein-calorie restriction on mechanical function of hypertrophied cardiac muscle

OBJECTIVE: To assess the effect of food restriction (FR) on hypertrophied cardiac muscle in spontaneously hypertensive rats (SHR). METHODS: Isolated papillary muscle preparations of the left ventricle (LV) of 60-day-old SHR and of normotensive Wistar-Kyoto (WKY) rats were studied. The rats were fed either an unrestricted diet or FR diet (50% of the intake of the control diet) for 30 days. The mechanical function of the muscles was evaluated through monitoring isometric and isotonic contractions. RESULTS: FR caused: 1) reduction in the body weight and LV weight of SHR and WKY rats; 2) increase in the time to peak shortening and the time to peak developed tension (DT) in the hypertrophied myocardium of the SHR; 3) diverging changes in the mechanical function of the normal cardiac muscles of WKY rats with reduction in maximum velocity of isotonic shortening and of the time for DT to decrease 50% of its maximum value, and increase of the resting tension and of the rate of tension decline. CONCLUSION: Short-term FR causes prolongation of the contraction time of hypertrophied muscles and paradoxal changes in mechanical performance of normal cardiac fibers, with worsening of the shortening indices and of the resting tension, and improvement of the isometric relaxation

Cicogna et al Protein-calorie restriction in hypertrophy Arq Bras Cardiol volume 72, (nº 4), 1999 Effects of Protein-Calorie Restriction on Mechanical Function of Hypertrophied Cardiac Muscle Original Article

Objective -To assess the effect of food restriction (FR) on hypertrophied cardiac muscle in spontaneously hypertensive rats (SHR). Methods -Isolated papillary muscle preparations of the left ventricle (LV) of 60-day-old SHR and of normo- . PCM can affect a series of organs and tissues. There is evidence in humans and especially in experimental animals that PCM can cause damage to the cardiovascular system. PCM can promote the following alterations: 1) clinical changes that vary from bradycardia to heart failure; 2) functional changes, such as reduction in cardiac output, in ventricular compliance, and in myocardial contractility; 3) biochemical changes, such as the activation of calciumdependent proteinase, reduction of the protein synthesis and of the RNA/DNA ratio, and an increase in DNA; and 4) morphological changes, such as dilation of the cardiac chambers, atrophy and/or degeneration of myocytes, interstitial and mitochondrial edema, and increase in colagen The spontaneously hypertensive rats (SHR) were developed as a genetic model of hypertension, which in many ways is similar to essential hypertension in man. The animals develop early left ventricular hypertrophy (LV), which is responsible for the maintenance of the normal cardiac function, despite the elevated systemic blood pressure (BP). Information in the literature about the influence of different types of nutritional deficiencies on the functional behavior of the hypertrophied muscle is scarce 7-9 . Yokota et al 7 observed that SHR fed a protein-deficient diet showed deterioration of LV function. Tabayashi et al 8 observed that dogs with LV hypertrophy that underwent chronic PCM had normal pump function and a reduced myocardial contractility. Olivetti et al 9 , studying SHR with nutritional anemia, observed LV dilation and dysfunction in those animals. Due to lack of information in the literature about the association between PCM and function of the hyper

Efeitos da inibição prolongada da enzima de conversão da angiotensina sobre as características morfológicas e funcionais da hipertrofia ventricular esquerda em ratos com sobrecarga pressórica persistente

OBJETIVO: Avaliar os efeitos do lisinopril (L) sobre as taxas de mortes (M), insuficiência cardíaca (ICC), características da remodelação miocárdica, geométrica e funcional do ventrículo esquerdo (VE), em ratos com estenose aórtica supravalvar (EAS). MÉTODOS: Ratos foram submetidos a EAS ou cirurgia simulada (GC:n=10). Randomizados após 6 semanas para receber L (GL:n=30) ou nenhum tratamento (GE:n=73) sendo avaliados 6s e 21s por estudos ecocardiográfico, hemodinâmico e morfológico concomitantes. RESULTADOS: As taxas de M (GE: 53,9% vs GL: 16,7% e ICC GE: 44,8% vs GL: 20% p0,05) sendo ambos maiores que os verificados no grupo GE. Comportamento semelhante foram obtidos com os valores da primeira derivada positiva e negativa da pressão do VE. CONCLUSÃO: em ratos com EAS o L reduziu as taxas de M e ICC e exerceu efeitos benéficos sobre a remodelação e a função do VE.OBJECTIVE: To assess the effects of lisinopril (L) on mortality (M) rate and congestive heart failure (CHF), and the characteristics of geometrical myocardial remodeling and left ventricular function in rats with supravalvular aortic stenosis (SAS). METHODS: Some Wistar rats underwent SAS or the simulated surgery (CG, n=10). After 6 weeks, the animals were randomized to receive lisinopril (LG, n=30) or no treatment (SG, n=73) for 15 weeks. Cardiac remodeling was assessed in the sixth and 21st weeks after the surgical procedures through concomitant echocardiographic, hemodynamic, and morphological studies. RESULTS: The M were 53.9% and 16.7% in SG and LG, respectively; the incidence of CHF was 44.8% and 20%, in SG and LG, respectively, (P0.05), and both were greater than those in SG;(P<0.05). Similar results were obtained with the values of the positive and negative first derivate of LV pressure. CONCLUSION: In rats with SAS, the treatment with L reduced M rate and ICC and had beneficial effects on geometrical myocardial remodeling and left ventricular function

Detection of Altered Risk Factors in Hospitalized Patients with Coronary Artery Disease

OBJECTIVE: To assess biochemical, anthropometric, and dietary variables considered risk factors for coronary artery disease. METHODS: Using anthropometrics, dietary allowance, and blood biochemistry, we assessed 84 patients [54 males (mean age of 55± 8 years) and 30 females (mean age of 57±7 years)], who had severe ( > or = 70% coronary artery obstruction) and nonsevere forms of coronary artery disease determined by cardiac catheterization. The severe form of the disease prevailed in 70% of the males and 64% of the females, and a high frequency of familial antecedents (92% ' 88%) and history of acute myocardial infarction (80% ' 70%) were observed. Smoking predominated among males (65%) and diabetes mellitus among females (43%). RESULTS: Males and females had body mass index and body fat above the normal values. Females with nonsevere lesions had HDL > 35 mg/dL, and this constituted a discriminating intergroup indicator. Regardless of the severity of the disease, hyperglycemia and hypertriglyceridemia were found among females, and cholesterolemia > 200 mg/dL in both sexes, but only males had LDL fraction > 160 mg/dL and homocysteine > 11.7 mmol/L. The male dietary allowance was inadequate in nutrients for homocysteine metabolism and in nutrients with an antioxidant action, such as the vitamins B6, C, and folate. Individuals of both sexes had a higher lipid and cholesterol intake and an inadequate consumption of fiber. The diet was classified as high-protein, high-fat, and low-carbohydrate. CONCLUSION: The alterations found had no association with the severity of lesions, indicating the need for more effective nutritional intervention

Papel relativo da remodelação geométrica do ventrículo esquerdo, morfológica e funcional do miocárdio na transição da hipertrofia compensada para a falência cardíaca em ratos com estenose aórtica supravalvar

OBJETIVO: Avaliar a contribuição relativa da remodelação geométrica do ventrículo esquerdo (VE) e das alterações morfológicas e funcionais do miocárdio, em ratos com estenose aórtica supravalvar (EAS), na fase de transição da hipertrofia compensada para a insuficiência cardíaca congestiva (ICC). MÉTODOS: Vinte e uma semanas após a indução da EAS os ratos foram classificados como controles (GC,n=13), não portadores (GE,n=11) ou portadores de insuficiência cardíaca congestiva (GE-IC,n=12).Todos os grupos foram avaliados com estudo ecocardiográfico, hemodinâmico e morfológico do miocárdio. RESULTADOS: Vinte e uma semanas após EAS: índice de massa (GE-IC>GE>GC,pGC, pGE>GC, pGE>GC,pGE>GC, pGE>GC, pSG>CG, pCG, pSG>CG, pSG>CG, pSG>CG, pSG>CG, p<0.05). In the SG-HF group, LV geometric remodeling was characterized by a significant increase in dimensions and relative thickness of the normal wall (excentric remodeling), whereas the SG group presented a concentric remodeling. Indexes of LV performance in the SG-HF group were significantly lower than those of the SG group. CONCLUSION: The SG-HF and SG groups differed primarily in the LV geometric remodeling and structural myocardial remodeling process, which established a chronically compensated state in the SG group and triggered CHF in the SG-HF group in the presence of equivalent degrees of impaired contractility

Remodelamento cardíaco: análise seriada e índices de detecção precoce de disfunção ventricular Remodelación cardiaca: análisis seriado e índices de detección precoz de disfunción ventricular Cardiac remodeling: serial analysis and indexes for early detection of ventricular dysfunction

FUNDAMENTO: A estenose aórtica supravalvar (EAo) é utilizada para o estudo da remodelação cardíaca (RC) por sobrecarga pressórica. Nesse modelo, não estão claramente estabelecidos o comportamento da RC desde a fase inicial, nem os melhores parâmetros para a identificação da disfunção ventricular. OBJETIVOS: 1) Caracterizar, precoce e evolutivamente, as modificações morfofuncionais durante a RC em ratos com EAo e 2) identificar o índice mais sensível para detecção do momento do aparecimento da disfunção diastólica e sistólica do ventrículo esquerdo (VE). MÉTODOS: Ratos Wistar foram divididos em dois grupos - controle (GC, n=13) e EAo (GEAo, n=24) - e estudados nas 3ª, 6ª, 12ª e 18ª semanas pós-cirurgia. Os corações foram analisados por meio de ecocardiograma (ECO). RESULTADOS: Ao final do experimento, as relações do VE, do ventrículo direito e dos átrios com o peso corporal final foram aumentadas no GEAo. O ECO mostrou que o átrio esquerdo sofreu uma remodelação significativa a partir da 6ª semana. No GEAo, a porcentagem de encurtamento endocárdico apresentou queda significativa a partir da 12ª semana e a porcentagem de encurtamento mesocárdico, na 18ª semana. A relação onda E e onda A (E/A) foi superior no GC em comparação ao GEAo em todos os momentos analisados. CONCLUSÕES: O ventrículo esquerdo dos ratos com EAo, durante o processo de remodelação, apresentou hipertrofia concêntrica, disfunção diastólica precoce e melhoria da função sistólica, com posterior deterioração do desempenho. Além disso, constatou-se que os índices ecocardiográficos mais sensíveis para a detecção da disfunção diastólica e sistólica são, respectivamente, a relação E/A e a porcentagem de encurtamento endocárdico.<br>FUNDAMENTO: La estenosis aórtica supravalvular (EAo) se utiliza para el estudio de la remodelación cardiaca (RC) por sobrecarga de presión. En este modelo, no están claramente establecidos el comportamiento del RC desde la fase inicial, ni los mejores parámetros para la identificación de la disfunción ventricular. OBJETIVO: 1) Caracterizar, precoz y evolutivamente, las modificaciones morfofuncionales durante el RC en ratones con EAo, y 2) identificar el índice más sensible para detección del momento de la aparición de la disfunción diastólica y sistólica del ventrículo izquierdo (VI). MÉTODOS: Ratones Wistar se dividieron en dos grupos - control (GC, n=13) y EAo (GEAo, n=24) - y estudiados en las 3ª, 6ª, 12ª y 18ª semanas post cirugía. Los corazones se analizaron por medio de ecocardiograma (ECO). RESULTADOS: Al final del experimento, las relaciones del VI, del ventrículo derecho y de los atrios con el peso corporal final fueron aumentadas en el GEAo. El ECO mostró que el atrio izquierdo sufrió una remodelación significativa a partir de la 6ª semana. En el GEAo, el porcentaje de acortamiento endocárdico presentó disminución significativa a partir de la 12ª semana y el porcentaje de acortamiento mesocárdico, en la 18ª semana. La relación onda E y onda A (E/A) fue superior en el GC en comparación al GEAo en todos los momentos analizados. CONCLUSIÓN: El ventrículo izquierdo de los ratones con EAo, durante el proceso de remodelación, presentó hipertrofia concéntrica, disfunción diastólica precoz y mejora de la función sistólica, con posterior deterioro del desempeño. Además de ello, se constató que los índices ecocardiográficos más sensibles para la detección de la disfunción diastólica y sistólica son, respectivamente, la relación E/A y el porcentaje de acortamiento endocárdico.<br>BACKGROUND: Supravalvar aortic stenosis (SVAS) is used to study overload-induced cardiac remodeling (CR). In this model, neither CR behavior since beginning stage nor the best parameters to identify ventricular dysfunction are clearly stated. Objective: 1) Characterizing, early and evolutively, morphological and functional modifications during CR in rats with SVAS and 2) identifying the most sensitive index for detecting the moment when the diastolic and systolic dysfunction first appeared in the left ventricle (LV). METHODS: Wistar Rats were divided into two groups - control (CG, n=13) and SVAS (SVASG, n=24) - and studied in post-surgical 3rd, 6th, 12th and 18th weeks. Hearts were analyzed by means of an echocardiogram (ECHO). RESULTS: By the end of the experiment, ratios between the LV, right ventricle and atria and the final body weight were increased in the SVASG. The ECHO showed that the left atrium underwent significant remodeling from the 6th on. The percent of endocardial shortening underwent significant drop as of the 12nd week and the percent of, as of the 18th week, in the SVASG. The ratio between E- wave and A-wave (E/A) was higher in CG compared to the SVASG in all events analyzed. CONCLUSIONS: During the remodeling process, the left ventricle of rats with SVAS presented concentric hypertrophy, early diastolic dysfunction and improvement of systolic function, with posterior performance deterioration. Besides this, the study found out the most sensitive echocardiographic indexes for detecting systolic and diastolic dysfunction are, respectively, the ratio E/A and the percent of endocardial shortening