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Non-alcoholic fatty liver disease (NAFLD) is a metabolic condition that comprises a spectrum of liver diseases. Non-pharmacological treatments such as functional food consumption and aerobic exercise training (AET) have been recommended. To evaluate the combined effects of acai pulp consumption and AET on the development of NAFLD induced by a high-fat diet. Male Fischer rats received either standard or high-fat diet. Animals (21.8% lard and 1% cholesterol) were treated with lyophilized acai pulp (1%), AET or acai plus AET for 8 weeks. Exercise capacity, body fat, serum metabolites (triacylglycerol, total cholesterol, and high-density lipoprotein) and enzymes (lipase, aspartate aminotransferase and alanine aminotransferase), liver macrovesicular steatosis and liver lipid peroxidation (thiobarbituric acid reactive substances—TBARS) were evaluated. Acai consumption reduced the levels of serum total cholesterol (p = 0.0185). AET with or without acai consumption increased the exercise capacity (p = 0.0097) and reduced body fat (p = 0.0001) similarly. Both AET and acai consumption individually reduced the concentrations of aspartate aminotransferase (p = 0.0103) and TBARS (p = 0.0014). AET with or without acai consumption reduced the degree of macrovesicular steatosis (p

espanolEl estudio tuvo como objetivo relacionar el riesgo coronario con la capacidad para las actividades de la vida diaria (AVD) en mujeres mayores que practican aerobic acuatico. La investigacion se realizo con mujeres mayores (n=40) que practicaban aquagym en gimnasios de la ciudad de Uba-MG. Los factores de riesgo coronario se evaluaron mediante el cuestionario adaptado de la Michigan Heart Association. Para evaluar la capacidad para las AVD se utilizo la escala de desempeno autopercibido en las actividades de la vida diaria. Se realizo la prueba de Komolgorov-Smirnov para verificar la normalidad de los datos y se aplico la prueba de correlacion de Pearson para verificar la relacion entre el riesgo coronario y la capacidad de las practicantes para las AVD. Se adopto un nivel de significancia de p≤0.05. El riesgo coronario se clasifico como “riesgo medio” (24,00 ± 3,81) y la capacidad para AVD se clasifico como “muy buena” (134,3 ± 21,10). Se encontro una correlacion significativa entre el riesgo coronario y la capacidad para las AVD. Se concluye que el aquagym aporta menor riesgo coronario y mayor capacidad de para las AVD en mujeres mayores. portuguesO estudo teve como objetivo avaliar o risco coronariano e a capacidade funcional em idosas praticantes de hidroginastica. A pesquisa foi realizada com idosas praticantes de hidroginastica em academias da cidade de Uba-MG. Avaliou-se os fatores de risco coronarianos atraves do questionario adaptado do Michigan Heart Association. Para avaliacao da capacidade funcional foi utilizada a escala de autopercepcao do desempenho em atividades da vida diaria. O risco coronariano foi classificado como “risco medio” e a capacidade funcional classificada como “muito boa”. Houve correlacao forte e negativa entre risco coronariano e a capacidade funcional. Conclui-se que a hidroginastica proporciona menor risco coronariano e maior capacidade funcional em idosas. portuguesO estudo teve como objetivo relacionar o risco coronariano com a capacidade para atividades da vida diaria (AVDs) em idosas praticantes de hidroginastica. A pesquisa foi realizada com idosas (n=40) praticantes de hidroginastica em academias da cidade de Uba-MG. Avaliou-se os fatores de risco coronarianos atraves do questionario adaptado do Michigan Heart Association. Para avaliacao da capacidade para AVDs foi utilizada a escala de autopercepcao do desempenho em atividades da vida diaria. Foi realizado o teste Komolgorov-Smirnov para verificar a normalidade dos dados e o teste de correlacao de Pearson aplicado para verificar a relacao entre o risco coronariano e a capacidade para AVDs das praticantes. Foi adotado um nivel de significância de p≤0,05. O risco coronariano foi classificado como “risco medio” (24,00 ± 3,81) e a capacidade para AVDs classificada como “muito boa” (134,3 ± 21,10). Foi encontrada correlacao significativa entre risco coronariano e a capacidade para AVDs. Conclui-se que a hidroginastica proporciona menor risco coronariano e maior capacidade para AVDs em idosas. EnglishThe aim of the study was to evaluate coronary risk and capacity for activities of daily living (ADLs) in elderly women practicing hydrogymnastic. The research was carried out with elderly women practicing hydrogymnastic in gyms in the city of Uba-MG. Coronary risk factors were assessed using the Michigan Heart Association adapted questionnaire. To assess ADLs capacity, the self-perception scale of performance in activities of daily living was used. The Komolgorov-Smirnov test was performed to verify the normality of the data and the Pearson correlation test applied to verify the relationship between the coronary risk and the practitioners' capacity for ADLs. A significance level of p≤0.05 was adopted. Coronary risk was classified as “medium risk” (24.00 ± 3.81) and the capacity for ADLs was classified as “very good” (134.3 ± 21.10). A significant correlation was found between coronary risk and the capacity for ADLs. It is concluded that water aerobics provides less coronary risk and greater capacity for ADLs in elderly women.

Introduction and Objectives: Stem cell therapy and aerobic exercise are non-pharmacological therapies following myocardial infarction. The aim of this study was to test whether aerobic exercise training enhances the benefits of mesenchymal stem cell (MSC) therapy on remodeling of the extracellular matrix and fetal gene expression in the left ventricle of infarcted rats. Methods: Myocardial infarction was surgically induced in six-week old male Wistar rats. Animals were divided into four groups: sedentary control (SC) and sedentary and stem cell treated (SCMSC); exercised (EX) and exercised and stem cell treated (EXMSC). Bone marrow-derived MSCs were immediately transplanted via the tail vein (concentration: 1×106 cells). Exercise training (five days/week, 60 min/day; 60% of maximal running speed) started 24 hours after myocardial infarction and lasted for 12 weeks. Results: Exercise capacity was higher in exercised than in sedentary groups. Animals in the SCMSC, EX and EXMSC groups exhibited better cardiac function than those in SC. Collagen content was lower in the SCMSC, EX and EXMSC groups than in SC and skeletal α-actin expression was lower in EX and EXMSC than in SC. The α/β-MHC ratio was higher in EX and EXMSC than in SC. The combination of therapies further reduced collagen content in the remote region of the infarct (∼24%) and skeletal α-actin expression (∼30%). Conclusion: Aerobic exercise training appears to enhance the beneficial effects of stem cell therapy on remodeling of the extracellular matrix and fetal gene expression in the left ventricle of rats with moderate infarction. Resumo: Introdução e objetivos: Terapia com células estromais e exercício aeróbio são estratégias não farmacológicas no tratamento pós-enfarte do miocárdio. O objetivo foi testar se o treinamento aeróbio amplia os benefícios da terapia com células mesenquimais estromais (CME) na remodelagem da matriz extracelular e na expressão de genes fetais no ventrículo esquerdo de ratos enfartados. Métodos: O enfarte do miocárdio foi induzido cirurgicamente em ratos com seis semanas de idade, divididos em quatro grupos: sedentário controle (SC) e tratado com CME (SCCME); exercício (EX) e exercício tratado com CME (EXCME). CME derivadas da medula óssea foram transplantadas através da veia caudal (concentração: 1 x 106 células). O treinamento aeróbio (5 dias/semana; 60 min/dia; 60% da velocidade máxima de corrida) iniciou 24 h após enfarte do miocárdio e durou 12 semanas. Resultados: A capacidade de exercício foi maior nos grupos exercitados que nos sedentários. Os grupos SCCME, EX e EXCME apresentaram melhor função cardíaca do que o SC. O conteúdo de colagénio foi menor nos grupos SCCME, EX e EXCME que no SC. A expressão da α-actina esquelética foi menor nos grupos EX e EXCME, comparada à do SC. A razão miosina de cadeia pesada α/β foi maior nos grupos EX e EXCME, comparada à do SC. A combinação das terapias reduziu ainda mais o conteúdo de colagénio na região remota (∼24%) e a expressão de α-actina esquelética (∼30%). Conclusão: O treinamento aeróbio parece potencializar os benefícios da terapia com células mesenquimais estromais na remodelagem da matriz extracelular do ventrículo esquerdo e expressão de genes fetais em ratos com enfarte moderado. Keywords: Exercise, Myocardial infarction, Stem cells, Genes, Collagen, Palavras-chave: Exercício, Enfarte do miocárdio, Células estromais, Genes, Colagénio

Introduction The structural and mechanical adaptations of the right ventricular (RV) myocytes in response to hypertension associated with low-intensity endurance training (LIET) have not been studied in experimental models. Objective To determine the effects of LIET on the structural and mechanical properties of RV myocytes in spontaneously hypertensive rats (SHRs). Methods Male SHRs and normotensive Wistar rats (age: 16 weeks) were allocated to groups (n=7): WIS (Wistar Controls); SHR-C (SHR Controls) and SHR-T (SHR Trained; 60 min/day, 50-60% of maximal exercise capacity, 5 days/week for 8 weeks). Systolic arterial pressure (SAP), isolated RV myocyte dimensions, contractility, intracellular Ca2+ transient ([Ca2+]i), and ventricular Ca2+ regulatory proteins were measured. The statistical analysis was performed by one-way ANOVA followed by the Tukey post hoc test (α=5%). Results LIET reduced the SAP in SHR animals (SHR-C, 164 ± 2 mmHg vs. SHR-T, 152 ± 4 mmHg; P0.05). LIET did not change the cell dimensions in the SHR-T. Neither hypertension nor LIET affected myocyte contractility or the expression of Ca2+ regulatory proteins in the RV of the SHR-C and SHR-T groups. Hypertension did not affect the amplitude of the [Ca2+]i transient or the time to half resting level (P>0.05), but increased the time to peak (WIS, 58 ± 1 ms vs. SHR-C, 79 ± 2 ms; P 0,05). O TABI não alterou as dimensões celulares nos SHR-T. Nem a hipertensão nem o TABI afetaram a contratilidade dos miócitos ou a expressão das proteínas reguladoras do Ca2+ no VD dos grupos SHR-C e SHR-T. A hipertensão não afetou a amplitude do transiente de [Ca2+]i e o tempo até a metade do nível de repouso (P > 0,05), mas aumentou o tempo até o pico (WIS, 58 ± 1 msvs. SHR-C, 79 ± 2 ms; P < 0,05). O TABI aumentou a amplitude do transiente de [Ca2+]i (WIS, 2,28 ± 0,07 F/F0 e SHR-C, 2,48 ± 0,08 F/F0 vs. SHR-T, 2,87 ± 0,08 F/F0 P < 0,05), mas não alterou os tempos até o pico e a metade do nível de repouso. Conclusão O TABI não teve efeito sobre as propriedades estruturais e mecânicas de miócitos do VD de SHR, embora tenha aumentado a amplitude do transiente de [Ca2+]i e reduzido a PAS. Nível de evidência I, Estudos terapêuticos – Investigação dos resultados do tratamento. RESUMEN Introducción Las adaptaciones estructurales y mecánicas de los miocitos del ventrículo derecho (VD) en respuesta a la hipertensión asociada al entrenamiento de resistencia de baja intensidad (ERBI) no se han estudiado en modelos experimentales de ratas. Objetivo Determinar los efectos del ERBI sobre las propiedades estructurales y mecánicas de los miocitos del VD en ratas espontáneamente hipertensas (SHR). Métodos Ratas SHR y ratas Wistar machos y normotensas (edad: 16 semanas) fueron distribuidas en grupos (n = 7): WIS (Wistar controle); SHR-C (SHR controle) y SHR-T (SHR entrenado; 60 min/día, el 50% a 60% de la capacidad máxima de ejercicio, 5 días/semana por 8 semanas). Se midieron presión arterial sistólica (PAS), dimensiones de los miocitos aislados del VD, contractilidad, transitorio intracelular de Ca2+ ([Ca2+]i) y proteínas reguladoras de Ca2+. El análisis estadístico se realizó mediante ANOVA one-way seguida por la prueba de Tukey post hoc (α = 5%). Resultados El ERBI redujo la PAS en los animales SHR (SHR-C, 164 ± 2 mmHg contra SHR-T 152 ± 4 mmHg, P < 0,05). La hipertensión aumentó la longitud de la célula (WIS, 156,8 ± 2,7 μm, SHR-C, 166,6 ± 3,1 μm; P < 0,05), pero no afectó el ancho o el volumen (P > 0,05). El ERBI no alteró las dimensiones de la célula en SHR-T. Ni la hipertensión y ni el ERBI afectaron la contractilidad de los miocitos o la expresión de proteínas reguladoras de Ca2+ en el VD de los grupos SHR-C y SHR-T. La hipertensión no afectó la amplitud del transitorio de [Ca2+]i y el tiempo hasta la mitad del nivel de reposo (P > 0,05), pero aumentó tiempo hasta el pico (WIS, 58 ± 1 ms contra SHR-C, 79 ± 2 ms; P < 0,05). El ERBI aumentó la amplitud del transitorio de [Ca2+]i (WIS, 2,28 ± 0,07 F/F0 y SHR-C, 2,48 ± 0,08 F/F0 contra SHR-T, 2,87 ± 0,08 F/F0 P < 0,05), pero no alteró los tiempos hasta el pico y la mitad del nivel de reposo. Conclusión El ERBI no tuvo efecto sobre las propiedades estructurales y mecánicas de los miocitos del VD de SHR, aunque aumentó la amplitud del transitorio de [Ca2+]i y redujo la PAS. Nivel de Evidencia I, Estudios terapéuticos - Investigación de los resultados del tratamiento.

The present study investigated the effects of aerobic physical training on the femoral morphological, densitometric and biomechanical properties in growing male rats subjected to protein-based malnutrition. Four-week-old male Wistar rats were randomized into groups of 10 animals: Control Sedentary (CS), Control Trained (CT), Malnourished Sedentary (MS) and Malnourished Trained (MT). Control and malnourished animals received diets with 12% protein and 6% protein, respectively. The trained groups were submitted to a treadmill running program for 8 weeks. Total proteins and albumin were analyzed in the animals' blood plasma. Histological, densitometric and biomechanical analyzes were performed on the animals' femur. Body mass gain, physical performance, biochemical markers and the femoral morphological, densitometric and biomechanical properties were determined. Exercise tolerance increased in trained groups. Malnourished animals exhibited lower serum protein and albumin levels than controls. Porosity and trabecular bone density were not different between groups. The femoral maximum load, maximum load until fracture, resilience, stiffness, tenacity and densitometric properties were reduced by malnutrition. Physical training associated with malnutrition exacerbated the impairment in the femoral maximum load, maximum load until fracture, bone mineral content and density. Aerobic physical training worsens the damages induced by protein-based malnutrition in the femoral biomechanical and densitometric properties of growing male rats.

Este estudo teve como objetivo comparar a autoestima de adolescentes praticantes e não praticantes de atividade física. A pesquisa foi realizada de forma descritiva com delineamento transversal. A amostra utilizada para coleta de dados foi composta por 50 adolescentes com idade entre 13 e 17 anos, de ambos os sexos, estudantes de escolas da rede privada e pública na cidade de Ubá-MG. Foram utilizados dois instrumentos, o Questionário Internacional de Atividade Física versão curta e a Escala de Autoestima de Rosenberg. Pôde-se observar através dos resultados que a maior parte dos adolescentes é ativa fisicamente, representando 76% da amostra, e que estes têm uma melhor autoestima em relação aos que são insuficientemente ativos (10,58+ 6,35 e 15,00+ 5,49, respectivamente). Os avaliados do sexo masculino também mostraram ter uma autoestima mais elevada comparada aos do sexo feminino, tendo como média 14,00+ 5,78 e 7,44+ 5,27, respectivamente. Esses resultados mostram que a atividade física interfere na autoestima dos adolescentes e que os praticantes têm melhor autoestima comparados aos não praticantes.

O consumo de bebida alcoólica é um costume antigo e está presente na vida de parte dos jovens brasileiros de hoje. Nos dias atuais, o álcool tem sido precursor de diversas doenças no planeta. Nesse sentido, o objetivo do presente estudo foi verificar o consumo de bebidas alcoólicas, bem como sua associação com o nível de atividade física e a qualidade de vida em estudantes do curso de Educação Física. Foi realizado um estudo descritivo com 26 universitários regularmente matriculados no curso de Educação Física, sendo aplicados três questionários: um que analisa a percepção subjetiva da qualidade de vida (WHOQOL); outro para avaliar padrões de consumo de bebida alcóolica (AUDIT), e, por fim, um que avalia o nível de atividade física (IPAQ). Pós coleta dos dados feita pelo Google Forms®, esses foram analisados. Os resultados mostram que a maioria dos estudantes foram classificados na zona de “Baixo risco” (80,77%), e que 87,5% desses são considerados fisicamente ativos. Além disso, não foram encontradas diferenças entre os domínios da qualidade de vida para os estudantes dos grupos classificados como “Baixo risco” ou “Uso de risco”. Conclui-se que a maior parte dos avaliados foi classificada como ativa e Baixo risco de consumo de bebidas alcoólicas. O consumo de bebidas alcoólicas não influenciou a qualidade de vida da amostra analisada.

A diminuição dos níveis de atividade física, o aumento do estresse e a queda no convívio social estão diretamente relacionadas à redução da qualidade de vida. O objetivo do presente estudo foi verificar se o nível de atividade física afeta a qualidade de vida de adultos durante a pandemia da Covid-19. Foi realizado um estudo descritivo em indivíduos de ambos os gêneros, sendo aplicados três questionários, um que avalia o nível de atividade física (IPAQ), o outro que analisa a percepção subjetiva da qualidade de vida (WHOQOL) e um terceiro, que avalia a percepção do efeito da pandemia na qualidade de vida. Foi visto que 46,16% dos participantes eram pouco ativos; aproximadamente 65% relataram piora na saúde mental e na qualidade de vida, sendo observadas alterações nos domínios físico, ambiental e social. Não foi possível relacionar a prática de atividade física com altos índices de qualidade de vida, mas observa-se que a pandemia influenciou negativamente a saúde mental e a qualidade de vida da população. Fazem-se necessários novos estudos e novas análises para melhor compreender essa relação entre a qualidade de vida e a atividade física em um cenário de pandemia.

Summary Aims Patients of pulmonary arterial hypertension (PAH) exhibit reduced functional capacity and exercise tolerance. Despite the evidences that exercise training is beneficial to this population, it is still being tested whether regular physical exercise can mitigate the complications of PAH. The aim of this review was to point out the cardiac functional and structural adaptations to exercise training in animal models of PAH, and highlight the cellular and molecular mechanisms underlying the benefits of exercise to individuals with PAH. News A systematic review of original articles published in PubMed and ScienceDirect databases was conducted by two independent researchers. Relevant information on animal model, exercise protocol, cardiac functional and structural adaptations was extracted and discussed. The results show that in rats with monocrotaline-induced PAH (50–60 mg/kg body weight), the predominant model used, aerobic continuous (treadmill running) and intermittent (voluntary wheel running) exercise training of moderate intensity, performed either prior or during the development of PAH, promote benefits to the myocardium. Moreover, the articles reveal that the cardiac function (i.e. restoration of right ventricle systolic and diastolic pressure, AT/ET ratio, TAPSE and cardiomyocyte contractility) and structure (i.e. reduced hypertrophy and fibrosis; improved profile of proteins related to cellular contraction and inflammatory response) are enhanced by exercise training. Furthermore, these exercise adaptations result in augmented exercise capacity and survival of animals with PAH. Conclusion Regular aerobic exercise of moderate intensity promotes cellular and molecular adaptations that improve myocardial function and structure along with increased exercise tolerance and survival.

Este estudo teve como objetivo verificar e comparar o nível de atenção e o nível de atividade física em alunos do ensino médio de uma escola em Piraúba-MG. Para isso, foram avaliados adolescentes de ambos os sexos com faixa etária de 15 a 17 anos. Como instrumentos de avaliação, foram utilizados dois testes. O primeiro teste aplicado foi o Questionário Internacional de Atividade Física (IPAQ- versão curta), que busca estimar o nível de atividade física dos avaliados. Em seguida, foi utilizado o Teste de Atenção por Cancelamento (TAC), composto por atividades de cancelamento de figuras em três etapas e níveis diferentes (TAC1, TAC2, TAC3), sendo utilizado para estimar o nível de atenção, ambos testes foram aplicados de forma presencial. Os resultados indicaram um melhor desempenho no teste de atenção dos alunos que foram classificados como Ativos, principalmente na primeira parte do teste (TAC1), com um melhor tempo e um menor percentual de erros. Assim, conclui-se que adolescentes ativos obtiveram um melhor resultado em uma parte específica do teste (TAC1), no que diz respeito ao nível de atenção seletiva.

This study evaluated the effect of aerobic exercise training (AET) and supplementation with acai on cardiac structure and function in rats submitted to a high-fat diet. Two-month old Fischer male rats were divided into 5 groups: Control (C), High-fat Diet (H), High-fat Diet + Acai (HA), High-fat Diet + AET (HT), High-fat Diet + Acai + AET (HAT). The high-fat diet had 21.8% lard and 1% cholesterol (H and HT), or supplemented with 1% lyophilized acai pulp (HA and HAT). The HT and HAT groups performed AET on a treadmill (5 days/week, 1 h/day, 60% of the maximum running speed) for 8 weeks. Exercise tolerance test were performed, and adiposity index calculated. After euthanasia, the left ventricle (LV) was dissected and processed for histological, single myocyte intracellular calcium ([Ca2+]i) transient and contractility, oxidative stress and gene expression analysis. AET improved running capacity and reduced the adiposity index. Both AET and acai supplementation inhibited the increase in the LV collagen content, the deleterious effects on the [Ca2+]i transient and contractility in cardiomyocytes and the increment in oxidative stress, caused by the consumption of a high-fat diet. Aerobic exercise training and acai supplementation can mitigate damage caused by high-fat diet in cardiac structure and function, though the combination of treatments had no additional effects.

Aim Investigate to what extent low-intensity swim training for six weeks counterbalances the adverse remodeling due to the advance of pathological hypertrophy in the left ventricle (LV) structural and mechanical properties in the early compensated phase of hypertension in male SHR. Main methods Four-month-old male SHR and Wistar rats were randomly divided into Sed (sedentary) and Ex (exercised) groups. The exercised rats were submitted to a swimming protocol (1 h/day, 5 times/week, no additional load) for six weeks. LV tissue and isolated myocytes were used to assess structural and mechanical properties. Myocytes were stimulted at frequencies (F) of 1 and 3 Hz at 37 °C. Key findings Exercised SHR showed improvement in cardiovascular parameters compared to sedentary SHR (mean arterial pressure: 13.22%; resting HR: 14.28.%). About structural and mechanical properties, swim training induced a decrease in LV myocyte thickness (10.85%), number of inflammatory cells (21.24%); collagen type III (74.23%) and type I (85.6%) fiber areas; amplitude of single myocyte shortening (47% to F1 and 28.46% to F3), timecourses of shortening (16.5% to F1 and 7.55% to F3) and relaxation (15.31% to F3) compared to sedentary SHR. Significance Six weeks of swim training attenuates the adverse remodeling of LV structural and mechanical properties in the early compensated phase of hypertension in male SHR.

In cardiomyocytes, calcium (Ca²⁺) release units comprise clusters of intracellular Ca²⁺ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca²⁺ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca²⁺ sparks (HC=7.61 ± 0.26 vs NC=4.79 ± 0.19 per 100 µm/s) and decreased its amplitude (HC=0.260 ± 0.08 vs NC=0.324 ± 0.10 ΔF/F0), full width at half-maximum amplitude (HC=1.05 ± 0.08 vs NC=1.26 ± 0.01 µm), total duration (HC=11.51 ± 0.12 vs NC=14.97 ± 0.24 ms), time to peak (HC=4.84 ± 0.06 vs NC=6.31 ± 0.14 ms), and time constant of decay (HC=8.68 ± 0.12 vs NC=10.21 ± 0.22 ms). These changes were partially reversed in HT rats (frequency of Ca²⁺ sparks=6.26 ± 0.19 µm/s, amplitude=0.282 ± 0.10 ΔF/F0, full width at half-maximum amplitude=1.14 ± 0.01 µm, total duration=13.34 ± 0.17 ms, time to peak=5.43 ± 0.08 ms, and time constant of decay=9.43 ± 0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

Made available in DSpace on 2015-02-02T12:39:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-09-01Bitstream added on 2015-02-02T13:08:12Z : No. of bitstreams: 1 S0101-32892014000300685.pdf: 739411 bytes, checksum: b6658e204d90cce856241c671c9acab9 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Este estudo investigou os efeitos do treinamento em corrida de baixa intensidade (TCBI) sobre propriedades estruturais e mecânicas da epífise proximal do fêmur de ratas osteopênicas. Ratas Wistar [idade = 20 semanas; massa corporal = 271,42 ± 17,6 g] foram submetidas à ovariectomia (OVX) ou laparotomia (SHAM) e alocadas em quatro grupos: corrida OVX (CO, n = 12), controle OVX (CONO, n = 12), corrida SHAM (CS, n = 12) e controle SHAM (CONS, n = 12). Quinze dias pós-cirurgia, os grupos CO e CS foram submetidos ao TCBI em esteira (16 m/min, 60 min/dia, cinco dias/semana) por 10 semanas. O TCBI não alterou os efeitos deletérios da osteopenia induzida por ovariectomia sobre a densidade mineral do fêmur, a quantidade de osso trabecular no trocanter e colo do fêmur, a tenacidade e a força máxima de fratura do colo do fêmur de ratas. This study investigated the effects of low-intensity running training (LIRT) on the structural and mechanical properties of the proximal femoral epiphysis in osteopenic female rats. Female Wistar rats [age = 20 weeks, body mass = 271.42 ± 17.6 g] were subjected to ovariectomy (OVX) or laparotomy (SHAM) and divided into four groups: running OVX (RO, n = 12), control OVX (CO, n = 12), running SHAM (RS, n = 12) and control SHAM (CS, n = 12). Two weeks after surgery RO and RS groups were submitted to a progressive LITR on a treadmill (60 min / day, 5 days / week) for 10 weeks. The LIRT did not alter the deleterious effects induced by ovariectomy on the femoral bone mineral density, the quantity of trabecular bone in the femoral great trocanter and neck, and femoral neck tenacity and resistance to fracture in female rats. Este estudio investigó los efectos del entrenamiento en carera de baja intensidad (ECBI) en las propiedades estructurales y mecánicas de la epífisis proximal femoral de ratas osteopénicas. Ratas Wistar con edad de 20 semanas (peso corporal: 271.42 ± 17,6 g) fueran sometidas a ooforectomía (OVX) o laparotomía (SHAM) y asignados en cuatro grupos: carera OVX (CO, n = 12), control OVX (CONO, n = 12), carera SHAM (CS, n = 12) y control SHAM (CONS, n = 12). Quince días después de la cirugía los grupos CO y CS fueran sometidos al ECBI (16 m/min; 60 min/día, 5 dias/semana) durante 10 semanas. El ECBI no cambió los efectos deletéreos de la osteopenia inducida por ooforectomía sobre la densidad mineral del fémur, la cantidad de hueso trabecular en el trocánter y cuello del fémur, la tenacidad y la resistencia ósea a la fractura del cuello del fémur de ratas. Universidade Federal de Viçosa Departamento de Biologia Geral Programa de Pós-Graduação em Biologia Celular e Estrutural Universidade Federal de Viçosa Centro de Ciências Biológicas e da Saúde Departamento de Veterinária Universidade Federal de Viçosa Centro de Ciências Biológicas e da Saúde Departamento de Educação Física Universidade Federal de Viçosa Centro de Ciências Biológicas Departamento de Nutrição e Saúde Universidade Federal de Viçosa Centro de Ciências Exatas e Tecnológicas Departamento de Estatística Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Medicina Veterinária Departamento de Apoio, Produção e Saúde Animal Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Medicina Veterinária Departamento de Apoio, Produção e Saúde Animal

We tested the effects of early mesenchymal stem cell (MSC) therapy associated with endurance exercise on the structural and functional cardiac remodeling of rats with myocardial infarctation (MI). Male Wistar rats (40 days old) were divided into 6 groups: control and exercise sham; control and exercise MI; and control and exercise MI MSC. MI was surgically induced and bone marrow-derived MSCs were immediately injected via caudal vein (concentration: 1 × 10(6 )cells). Twenty-four hours later ET groups exercised on a treadmill (5 days/week; 60 min/day; 60% of maximal running velocity) for 12 weeks. Structural and functional changes were determined by echocardiography. Contractility and intracellular global calcium ([Ca(2 +)]i) transient were measured in myocytes from the left ventricular (LV) non-infarcted area. Calcium regulatory proteins were measured by Western blot. MI increased (p < 0.05) heart, ventricular and LV weights and its ratios to body weight; LV internal dimension in diastole (LVID-D) and in systole (LVID-S) and LV free wall in diastole (LVFW-D), but reduced the thickness of interventricular septum in systole (IVS-S), ejection fraction (EF) and fractional shortening (FS). MI augmented (p < 0.05) the times to peak and to half relaxation of cell shortening as well as the amplitude of the [Ca(2 +)]i transient and the times to peak and to half decay. Early MSCs therapy restored LVFW-D, IVS-S and the amplitude and time to half decay of the [Ca(2 +)]i transient. Early endurance exercise intervention increased (p < 0.05) LVFW-S, IVS-S, EF and FS, and reduced the times to peak and to half relaxation of cell shortening, and the amplitude of the [Ca(2 +)]i transient. Exercise training also increased the expression of left ventricular SERCA2a and PLBser16. Nevertheless, the combination of these therapies did not cause additive effects. In conclusion, combining early MSCs therapy and endurance exercise does not potentiate the benefits of such treatments to structural and functional cardiac remodeling in infarcted rats.

The effect of a treadmill running program on physical performance and morphofunctional adaptations was investigated in control and malnourished rats. Male 4-week old Wistar rats were randomized in groups of 12 animals: control trained (CT), control sedentary (CS), malnourished trained (MT) and malnourished sedentary (MS). Control and malnourished animals received chow with 12% protein or 6% protein, respectively. Trained groups were subjected to a treadmill running program for 8 weeks. Physical performance, biochemical parameters, cardiomyocytes morphology and biomechanics were determined. Malnourished animals presented reduction in body mass, serum levels of total protein, albumin and hemoglobin compared to the control groups. At 1 and 3 Hz cardiomyocytes from CT and MT showed higher cell shortening, speed of contraction and relaxation compared to the other groups. At 3 Hz cardiomyocytes from MS showed reduction in cell shortening and speed of contraction compared to CS. Protein restriction does not prevent the improvement in physical performance or cardiomyocytes biomechanical efficiency and growth in response to exercise. These findings could represent a modulatory effect of exercise to maintain cardiomyocyte growth at the expense of reducing the rate of body growth in order to ensure proper cellular function in conditions of cardiovascular overload imposed by exercise.

We tested the effects of low-intensity endurance training (LIET) on the structural and mechanical properties of right (RV) and left ventricular (LV) myocytes. Male Wistar rats (4 mo old) were randomly divided into control (C, n = 7) and trained (T, n = 7, treadmill running at 50–60% of maximal running speed for 8 wk) groups. Isolated ventricular myocyte dimensions, contractility, Ca2+transients {intracellular Ca2+concentration ([Ca2+]i)}, and ventricular [Ca2+]iregulatory proteins were measured. LIET augmented cell length (C, 152.5 ± 2.0 μm vs. T, 162.2 ± 2.1 μm; P < 0.05) and volume (C, 5,162 ± 131 μm3vs. T, 5,506 ± 132 μm3; P < 0.05) in the LV but not in the RV. LIET increased cell shortening (C, 7.5 ± 0.3% vs. T, 8.6 ± 0.3%; P < 0.05), the [Ca2+]itransient amplitude (C, 2.49 ± 0.06 F/F0vs. T, 2.82 ± 0.06 F/F0; P < 0.05), the expression of sarcoplasmic reticulum Ca2+-ATPase 2a (C, 1.07 ± 0.13 vs. T, 1.59 ± 0.12; P < 0.05), and the levels of phosphorylated phospholamban at serine 16 (C, 0.99 ± 0.11 vs. T, 1.34 ± 0.10; P < 0.05), and reduced the total phospholamban-to-sarcoplasmic reticulum Ca2+-ATPase 2a ratio (C, 1.19 ± 0.15 vs. T, 0.40 ± 0.16; P < 0.05) in the LV without changing such parameters in the RV. In conclusion, LIET affected the structure and improved the mechanical properties of LV but not of RV myocytes in rats, helping to characterize the functional and morphological changes that accompany the endurance training-induced cardiac remodeling.

The aim of the present study was to verify the effects of low-intensity endurance training and detraining on the mechanical and molecular properties of cardiomyocytes from spontaneously hypertensive rats (SHRs). Male SHRs and normotensive control Wistar rats at 16-weeks of age were randomly divided into eight groups of eight animals: NC8 and HC8 (normotensive and hypertensive control for 8weeks); NT8 and HT8 (normotensive and hypertensive trained at 50-60% of maximal exercise capacity for 8weeks); NC12 and HC12 (normotensive and hypertensive control for 12weeks); NDT and HDT (normotensive and hypertensive trained for 8weeks and detrained for 4weeks). The total exercise time until fatigue (TTF) was determined by a maximal exercise capacity test. Resting heart rate (RHR) and systolic arterial pressure (SAP) were measured. After the treatments, animals were killed by cervical dislocation and left ventricular myocytes were isolated by enzymatic dispersion. Isolated cells were used to determine intracellular global Ca(2+) ([Ca(2+)]i) transient and cardiomyocyte contractility (1Hz; ~25°C). [Ca(2+)]i regulatory proteins were measured by Western blot, and the markers of pathologic cardiac hypertrophy by quantitative real-time polymerase chain reaction (q-RT-PCR). Exercise training augmented the TTF (NC8, 11.4±1.5min vs. NT8, 22.5±1.4min; HC8, 11.7±1.4min vs. HT8, 24.5±1.3min; P

FUNDAMENTO: A capacidade aeróbica é fundamental para o desempenho físico, e a baixa capacidade aeróbica está relacionada ao desencadeamento de diversas doenças cardiovasculares. OBJETIVO: Comparar a contratilidade e a morfologia de cardiomiócitos isolados de ratos com baixo desempenho e desempenho padrão para o exercício físico. MÉTODOS: Ratos Wistar, com 10 semanas de idade, foram submetidos a um protocolo de corrida em esteira até a fadiga, e foram divididos em dois grupos: Baixo Desempenho (BD) e Desempenho Padrão (DP). Em seguida, após eutanásia, o coração foi removido rapidamente e, por meio de dissociação enzimática, os cardiomiócitos do ventrículo esquerdo foram isolados. O comprimento celular e dos sarcômeros e a largura dos cardiomiócitos foram medidos usando-se um sistema de detecção de bordas. Os cardiomiócitos isolados foram estimulados eletricamente a 1 e 3 Hz e a contração celular foi medida registrando-se a alteração do seu comprimento. RESULTADOS: O comprimento celular foi menor no grupo BD (157,2 ± 1,3µm; p < 0,05) em relação ao DP (161,4 ± 1,3 µm), sendo o mesmo resultado observado para o volume dos cardiomiócitos (BD, 25,5 ± 0,4 vs. DP, 26,8 ± 0,4 pL; p < 0,05). Os tempos para o pico de contração (BD, 116 ± 1 vs. DP, 111 ± 2ms) e para o relaxamento total (BD, 143 ± 3 vs. DP, 232 ± 3 ms) foram maiores no grupo BD. CONCLUSÃO: Conclui-se que os miócitos do ventrículo esquerdo dos animais de baixo desempenho para o exercício físico apresentam menores dimensões que os dos animais de desempenho padrão, além de apresentarem perdas na capacidade contrátil. BACKGROUND: Aerobic capacity is essential to physical performance, and low aerobic capacity is related to the triggering of various cardiovascular diseases. OBJECTIVE: To compare the morphology and contractility of isolated rat cardiomyocytes with low performance and standard performance for exercise. METHODS: Wistar rats with 10 weeks of age underwent a protocol of treadmill running to fatigue, and were divided into two groups: Low Performance (LP) and Standard Performance (SP). Then, the animals were sacrificed, the heart was quickly removed and, by means of enzymatic dissociation, left ventricular cardiomyocytes were isolated. The cell and sarcomeres length and width of cardiomyocytes were measured using an edge detection system. The isolated cardiomyocytes were electrically stimulated at 1 and 3 Hz and cell contraction was measured by registering the change of their length. RESULTS: The cell length was shorter in the LP group (157.2 1.3µm; p < 0.05) compared to SP (161.4 1.3µm), and the same result was observed for the volume of cardiomyocytes (LP, 25.5 0.4. vs. SP, 26.8 ± 0.4 pL; p < 0.05). The time to peak contraction (LP, 116 1 vs. SP 111 2ms) and total relaxation (LP, 143 3 vs. SP 232 3ms) were higher in the LP group. CONCLUSION: We conclude that left ventricular myocytes of animals with low performance for exercise are smaller than animals with standard performance. In addition to that, they present losses in contractile capacity.

Aerobic capacity is essential to physical performance, and low aerobic capacity is related to the triggering of various cardiovascular diseases.To compare the morphology and contractility of isolated rat cardiomyocytes with low performance and standard performance for exercise.Wistar rats with 10 weeks of age underwent a protocol of treadmill running to fatigue, and were divided into two groups: Low Performance (LP) and Standard Performance (SP). Then, the animals were sacrificed, the heart was quickly removed and, by means of enzymatic dissociation, left ventricular cardiomyocytes were isolated. The cell and sarcomeres length and width of cardiomyocytes were measured using an edge detection system. The isolated cardiomyocytes were electrically stimulated at 1 and 3 Hz and cell contraction was measured by registering the change of their length.The cell length was shorter in the LP group (157.2 ± 1.3 µm; p0.05) compared to SP (161.4 ± 1.3 µm), and the same result was observed for the volume of cardiomyocytes (LP, 25.5 ± 0.4 vs. SP, 26.8 ± 0.4 pL; p0.05). The time to peak contraction (LP, 116 ± 1 vs. SP 111 ± 2 ms) and total relaxation (LP, 143 ± 3 vs. SP 232 ± 3 ms) were higher in the LP group.We conclude that left ventricular myocytes of animals with low performance for exercise are smaller than animals with standard performance. In addition to that, they present losses in contractile capacity.