Effects of Physical Training on the Myocardium of Oxariectomized LDLr Knockout Mice: MMP 2/9, Collagen I/III, Inflammation and Oxidative Stress / Efeitos do Treinamento Físico sobre o Miocárdio de Camundongos LDLr Knockout Ovariectomizadas: MMP-2 e -9, Colágeno I/III, Inflamação e Estresse Oxidativo

Abstract Background: The emergence of coronary heart disease is increased with menopause, physical inactivity and with dyslipidemia. Physical training is known to promote the improvement of cardiovascular functions. Objective: To investigate the effects of aerobic physical training on the left ventricle in ovariectomized LDL knockout mice. Methods: Thirty animals were divided into 6 groups (n = 5): Sedentary non-ovariectomized control; Sedentary ovariectomized control; Trained ovariectomized control; Sedentary non-ovariectomized LDL-knockout, sedentary ovariectomized LDL-knockout and trained ovariectomized LDL-knockout. We analyzed the average parameters of apparent density of collagen fibers types I and III, and metalloproteinase type 2 and type 9, were considered significant p < 0.05. Results: The results showed that the proposed exercise protocol altered the volume of type I collagen fibers, altered collagen remodeling parameters (MMP-2), and also reduced the 8-hydroxy-2'-deoxyguanosine (8OHdG) oxidative stress parameter. Conclusion: Moderate intensity aerobic training acts on collagen fiber volume, on collagen remodeling with the reduction of oxidative stress in the left ventricles of ovariectomized LDL-knockout mice.

Resumo Fundamento: O surgimento da doença cardíaca coronariana aumenta com a menopausa, inatividade física e dislipidemia. Sabe-se que o treinamento físico promove a melhora das funções cardiovasculares Objectivo: Investigar os efeitos do treinamento físico aeróbico sobre o ventrículo esquerdo em camundongos LDL knockout ovariectomizadas. Métodos: Trinta animais foram divididos em 6 grupos (n = 5): controle sedentário não ovariectomizado, controle sedentário ovariectomizado, controle treinado ovariectomizado, sedentário LDL-knockout não ovariectomizado, sedentário LDL-knockout ovariectomizado e treinado LDL-knockout ovariectomizado. Analisamos os parâmetros médios da densidade de volume de fibras colágenas tipo I e III, e metaloproteinases 2 e 9. Valores de p < 0,05 foram considerados significativos. Resultados: Os resultados mostram que o protocolo de exercício proposto alterou o volume de fibras colágenas do tipo I e os parâmetros de remodelamento do colágeno (MMP-2), e ainda reduziu o parâmetro de estresse oxidativo do 8-hidroxi-2'-deoxiganosina (8-OhdG). Conclusão: O treinamento aeróbico de intensidade moderada age sobre o volume das fibras colágenas e sobre o remodelamento de colágeno, com redução do estresse oxidativo em ventrículos esquerdos de camundongos ovariectomizados LDLr Knockout.

Effect of mild aerobic exercise in atrial granules of mice with chronic Chagas Disease / Efeito do exercício aeróbico leve em grânulos atriais de camundongos com doença de Chagas crônica

Background: Chagas disease presents in different clinical forms, ranging from asymptomatic to acute, with destruction of heart cells and a possibility of death. In the chronic phase, the parasites can cause serious injuries to different tissues.Objectives: Our objective was to study the effects of physical exercise (swimming) in atrial granules and components of cardiomyocytes in mice with chronic Chagas disease. Methods: In total, 20 male mice were divided into four different groups: untrained control (UC), trained control (TC), untrained infected (UI), and trained infected (TI). In the UI and TI groups, 1,000 forms of Trypanosoma cruzi (Y strain) were inoculated intraperitoneally. After 40 days of infection and proof of chronic phase, the exercise protocol began. The UC and UI groups performed exercise for 10 min/day, and the TC and TI groups followed a training protocol five times a week for 30 minutes during 8 weeks. Ultrathin sections were subjected to morphometric and stereological analyses using electron photomicrographs (x15000) obtained by transmission electron microscopy.Results: The TI group showed the lowest percentage of small granules (58%), while the UI group presented 80% of these granules. The volume density of the Golgi complex and myofibrils in the TI group were reduced compared with those in the UI group, while the parameters of atrial granules and mitochondria increased. Conclusion: Our results suggest that mild physical exercise changes the morphological and morphometric parameters of granules and organelles in the cardiac atrium of mice infected with T. cruzi, and produces moderate beneficial effects on the cardiovascular system

Obesidade infantil e fatores de risco cardiovasculares / Childhood obesity and cardiovascular risk factors

Introdução: A obesidade é uma doença de prevalência crescente e que, atualmente, assume caráter epidemiológico como principal problema de saúde pública na sociedade contemporânea. Decorre de fatores genéticos, comportamentais e ambientais e pode se iniciar em qualquer idade. Entretanto quando surge precocemente nos primeiros anos de vida, predispõe à sua presença em idades mais tardias e está associada a diferentes comorbidades. Objetivo: Revisar a literatura sobre a etiologia da obesidade infantil e identificar os principais fatores de risco cardiovasculares associados à obesidade. Métodos: Utilizaram-se os sites científicos Medline, Scielo e Pubmed para consultar as palavras-chave: obesidade, crianças e doenças cardiovasculares. Resultados: Os fatores comportamentais e ambientais foram citados como principais causas da epidemia de obesidade. Os principais fatores de risco cardiovasculares estão associados à hipertensão e disfunção autonômica. Conclusão: A obesidade infantil está relacionada com a prevalência aumentada de doenças metabólicas e cardiovasculares em idade precoce.

Introduction: Obesity is a disease of increasing prevalence, which currently assumes an epidemic main public health problem in contemporary society. Stems from genetic, behavioral, environmental, and can start at any age. However when it comes within the first years of life, predisposing to its presence at older ages and is associated with various comorbidities. Objective: To review the literature on the etiology of childhood obesity and to identify major cardiovascular risk factors associated with obesity. Methods: We used the scientific websites Medline, PubMed and Scielo to check the keywords: obesity, children and cardiovascular diseases. Results: The behavioral and environmental factors were cited as major causes of the obesity epidemic. The major cardiovascular risk factors are associated with hypertension and autonomic dysfunction. Conclusion: Childhood obesity is associated with increased prevalence of metabolic and cardiovascular diseases at an early age.