Strength training improves heart function, collagen and strength in rats with heart failure.

BACKGROUND/OBJECTIVES: Myocardial infarction (MI) frequently leads to cardiac remodeling and failure with impaired life quality, playing an important role in cardiovascular deaths. Although physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases, the effects of strength training (ST) on the structural and functional aspects of cardiac remodeling need to be further documented. In this study, we aimed to investigate the role of a linear block ST protocol in the rat model of MI. METHODS AND RESULTS: After 6 weeks of MI induction or sham surgery, male adult rats performed ST for the following 12 weeks. The ladder-based ST program was organized in three mesocycles of 4 weeks, with one load increment for each block according to the maximal carrying load test. After 12 weeks, the infarcted-trained rats exhibited an increase in performance, associated with reduced cardiac hypertrophy and pulmonary congestion compared with the untrained group. Despite not changing MI size, the ST program partially prevented cardiac dilatation and ventricular dysfunction assessed by echocardiography and hemodynamics, and interstitial fibrosis evaluated by histology. In addition, isolated cardiac muscles from infarcted-trained rats had improved contractility parameters in a steady state, and in response to calcium or stimuli pauses. CONCLUSIONS: The ST in infarcted rats increased the capacity to carry mass, associated with attenuation of cardiac remodeling and pulmonary congestion with improving cardiac function that could be attributed, at least in part, to the improvement of myocardial contractility.

Effect of Supervised and Unsupervised Exercise Training in Outdoor Gym on the Lifestyle of Elderly People.

The aim of this study was to investigate the effectiveness of supervised and unsupervised physical training programs using outdoor gym equipment on the lifestyles of elderly people. METHODS: physically independent elderly people were randomly distributed into three groups: supervised training (n: 20; ST), unsupervised training (n: 20; UT) and control (n: 20; C). The ST and UT groups completed a 12-week program, with exercises performed three times a week. The ST group underwent weekly 30 min sessions consisting of a 5 min warm-up (walking at 60% of HRmax), followed by 20 sets of 30, "monitored by a metronome with 30" of passive recovery between sets and a five-minute cool-down. The following equipment was used: elliptical, rowing, surfing and leg press. The UT group was instructed to freely attend the gym and train spontaneously using the same equipment used by ST. Lifestyle changes were evaluated using a questionnaire containing specific domains. RESULTS: no significant differences were identified in the domains for family, physical activity, nutrition, smoking, sleep, behavior, introspection, work and overall score; however, the values corresponding to the alcohol domain for the ST and UT groups were lower (p < 0.05) than the C group, remaining even lower after the 12 weeks of intervention. Time effect (p < 0.05) was found only in the ST group for the physical domains, sleep, behavior and overall score. CONCLUSION: elderly people submitted to supervised and unsupervised physical exercise programs using outdoor gym equipment present positive changes in lifestyle parameters compared to physical inactive elderly people.

A High-Fat Diet Induces Cardiac Damage in Obesity-Resistant Rodents with Reduction in Metabolic Health.

BACKGROUND/AIMS: Obesity resistance is associated with the complex interaction of stringent and environmental factors that confer the ability to resist mass gain and body fat deposition, even when eating high-calorie diets. Considering that there are numerous gaps in the literature on the metabolic processes that explain Obesity resistance, specifically in relation to oxidative stress, the purpose of the study was to investigate whether obesity-resistant (OR) rats develop elevated reactive oxygen species in cardiac tissue. METHODS: Wistar rats were initially randomized into two groups: a standard diet (SD) and a high-fat diet (HFD) group. The SD and HFD groups were further divided into control (C), OR, and obese prone (OP) subgroups based on body weight. This criterion consisted of organizing the animals in each group in ascending order according to body weight (BW), and the cutoff point was identified in the animals by terciles: 1) lower BW; 2) intermediate BW; and 3) higher BW. Rats were sacrificed on the 14th week, and serum and organs were collected. Nutritional assessment, food profiles, histological analysis, comorbidities, and cardiovascular characteristics were determined. RESULTS: BW showed a significant difference between the standard diet and high-fat diet groups in the 4th week of the experimental protocol, characterizing obesity. In the 4th week, after the characterization of Obesity resistance, there was a significant difference in BW between groups C, OP, and OR. The OP and OR groups showed a significant increase in caloric intake in relation to the C group. The OP group showed a significant increase in final BW, retroperitoneal fat pad mass, sum of corporal fat deposits and reactive oxygen species, in relation to groups C and OR. The area under the glycemic curve, insulin resistance index and basal glucose were elevated in the OP group in relation to the C. OP also promoted an increase in HOMA-IR when compared with C. OR rats showed a non-significant increase in insulin and HOMA-IR in OR vs. C (p = ~0.1), but no significant differences were observed between OP vs. OR for these parameters, suggesting that both groups suffered from decreased metabolic health. Total cardiac mass, left ventricular cross-sectional area, and cholesterol levels were significantly elevated in the OP and OR groups compared with the C group. CONCLUSION: A high-fat diet induces cardiac damage in obesity-resistant rodents with reduction in metabolic health.

Aerobic Exercise Training Improves Calcium Handling and Cardiac Function in Rats with Heart Failure Resulting from Aortic Stenosis.

Aerobic exercise training (AET) has been used to manage heart disease. AET may totally or partially restore the activity and/or expression of proteins that regulate calcium (Ca2+) handling, optimize intracellular Ca2+ flow, and attenuate cardiac functional impairment in failing hearts. However, the literature presents conflicting data regarding the effects of AET on Ca2+ transit and cardiac function in rats with heart failure resulting from aortic stenosis (AoS). This study aimed to evaluate the impact of AET on Ca2+ handling and cardiac function in rats with heart failure due to AoS. Wistar rats were distributed into two groups: control (Sham; n = 61) and aortic stenosis (AoS; n = 44). After 18 weeks, the groups were redistributed into: non-exposed to exercise training (Sham, n = 28 and AoS, n = 22) and trained (Sham-ET, n = 33 and AoS-ET, n = 22) for 10 weeks. Treadmill exercise training was performed with a velocity equivalent to the lactate threshold. The cardiac function was analyzed by echocardiogram, isolated papillary muscles, and isolated cardiomyocytes. During assays of isolated papillary muscles and isolated cardiomyocytes, the Ca2+ concentrations were evaluated. The expression of regulatory proteins for diastolic Ca2+ was assessed via Western Blot. AET attenuated the diastolic dysfunction and improved the systolic function. AoS-ET animals presented an enhanced response to post-rest contraction and SERCA2a and L-type Ca2+ channel blockage compared to the AoS. Furthermore, AET was able to improve aspects of the mechanical function and the responsiveness of the myofilaments to the Ca2+ of the AoS-ET animals. AoS animals presented an alteration in the protein expression of SERCA2a and NCX, and AET restored SERCA2a and NCX levels near normal values. Therefore, AET increased SERCA2a activity and myofilament responsiveness to Ca2+ and improved the cellular Ca2+ influx mechanism, attenuating cardiac dysfunction at cellular, tissue, and chamber levels in animals with AoS and heart failure.

Nível de conhecimento do profissional de educação física sobre prescrição de exercício de aeróbio e doenças crônicas / Nivel de conocimiento de los profesionales de la educación física sobre la prescripción del ejercicio aeróbico y las enfermedades crónicas / Level of knowledge of physical education professionals about aerobic exercise prescription and chronic diseases

Objetivo: A prática regular de exercício aeróbio é fundamental para a saúde de adultos saudáveis, idosos e no controle de doenças crônicas e agravos nãotransmissíveis. Entretanto, deve ser prescrito segundo as diretrizes mundiais específicas para cada população. o objetivo era investigar o conhecimentodos profissionais de Educação Física atuantes em academias de ginástica em relação aos critérios que compõe a prescrição de exercício aeróbio parapessoas com diagnóstico de doenças crônicas e agravos não transmissíveis. Métodos: 610 profissionais de Educação Física atuantes em academias de São Paulo foram avaliados. O nível de conhecimento sobre as recomendações daprescrição do exercício aeróbio foi avaliado por meio de questionário construído para esse estudo. A análise dos dados foi realizada por meio do testeQui-Quadrado com significância de 5%. Resultados: O maior percentual de acerto ocorreu para prescrição do exercício aeróbio para Obesidade (49.2%) seguido por Diabetes tipo 2 (41.5%). Poroutro lado, o conhecimento sobre o Câncer (6.9%) apresentou o menor percentual de acerto. Outro resultado que merece destaque foi que, exceto paraSíndrome Metabólica (21%), o maior percentual de acerto foi observado para os critérios frequência semanal e duração do exercício aeróbio. Conclusão: O conhecimento dos profissionais de Educação Física em relação à recomendação para prescrição do exercício aeróbio foi significativamentemaior para obesos comparado a câncer, Diabetes tipo 2 e síndrome metabólica.(AU)

Objective: Regular practice of aerobic exercise is critical to control of chronic non-communicable diseases and injuries. However, the world-specificguidelines for each population must be prescribed second. The aim was to investigate the knowledge of physical education professionals working ingymnasiums in relation to the criteria that make up the prescription of aerobic exercise for people diagnosed with chronic non-communicable diseasesand injuries. Methods: 610 Physical Education professionals working in academies in São Paulo were evaluated. The knowledge of the recommendation of the aerobicexercise prescription was evaluated through a questionnaire built for this study. The chi square test was used to analyze data with significance of p <0.05.Results: The highest values for correct answers was found to prescription of aerobic exercise for obesity (49.2%) followed by type 2 diabetes (41.5%). Onthe other hand, knowledge about Cancer (6.9%) had the lowest percentage of correct answers. Another result worth mentioning was that, except forMetabolic Syndrome (21%), the highest percentage of correct answers was observed for the weekly frequency and duration criteria. Conclusion: The knowledge of Physical Education professionals regarding the recommendation to prescribe aerobic exercise was significantly higher forobese compared to cancer, type 2 diabetes and metabolic syndrome.(AU)

Objetivo: La práctica regular de ejercicio aeróbico es fundamental para la salud de adultos sanos, ancianos y para el control de enfermedades crónicas yenfermedades no transmisibles. Sin embargo, debe prescribirse de acuerdo con pautas globales específicas para cada población. El objetivo fue investigarel conocimiento de los profesionales de Educación Física que actúan en los gimnasios en relación a los criterios que componen la prescripción delejercicio aeróbico para personas diagnosticadas con enfermedades crónicas y enfermedades no transmisibles.Métodos: Fueron evaluados 610 profesionales de Educación Física que actúan en gimnasios de São Paulo. El nivel de conocimiento sobre lasrecomendaciones de prescripción de ejercicio aeróbico se evaluó mediante un cuestionario construido para este estudio. El análisis de datos se realizómediante la prueba Chi-Cuadrado con una significación del 5%.Resultados: El mayor porcentaje de aciertos se presentó para la prescripción de ejercicio aeróbico para la Obesidad (49.2%) seguido de Diabetes Tipo 2(41.5%). Por otro lado, el conocimiento sobre Cáncer (6.9%) tuvo el menor porcentaje de aciertos. Otro resultado digno de mención fue que, conexcepción del Síndrome Metabólico (21%), el mayor porcentaje de respuestas correctas se observó para los criterios frecuencia semanal y duración delejercicio aeróbico.Conclusión: El conocimiento de los profesionales de Educación Física sobre la recomendación de prescripción de ejercicio aeróbico fue significativamentemayor para obesos en comparación con cáncer, Diabetes tipo 2 y síndrome metabólico.(AU)

Type 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function, impaired Ca2+ handling and protein carbonylation damage.

AIMS: To investigate whether the obesity associated to T2DM presented cardiomyocyte myocardial contractility dysfunction due to damage in Ca2+ handling, concomitantly with increased biomarkers of oxidative stress. METHODS: Male Wistar rats were randomized into two groups: control (C): fed with standard diet; and obese (Ob) that fed a saturated high-fat. After the characterization of obesity (12 weeks), the Ob animals were submitted to T2DM induction with a single dose of intraperitoneal (i.p.) injection of streptozotocin (30 mg/kg). Thus, remained Ob rats that were characterized as to the presence (T2DMOb; n = 8) and/or absence (Ob; n = 10) of T2DM. Cardiac remodeling was measured by post-mortem morphological, isolated cardiomyocyte contractile function, as well as by intracellular Ca2+-handling analysis. RESULTS: T2DMOb presented a significant reduction of all fat pads, total body fat and adiposity index. T2DMOb group presented a significant increase in protein carbonylation and superoxide dismutase (SOD) activity, respectively. T2DMOb promoted elevations in fractional shortening (15.6 %) and time to 50 % shortening (5.8 %), respectively. Time to 50 % Ca2+ decay was prolonged in T2DMOb, suggesting a possible impairment in Ca2+recapture and/or removal. CONCLUSION: Type 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function with protein carbonylation damage and impaired Ca2+ handling.

High-fat, high-sucrose, and combined high-fat/high-sucrose diets effects in oxidative stress and inflammation in male rats under presence or absence of obesity.

The study examines the influence of three types of hypercaloric diets on metabolic parameters, inflammatory markers, and oxidative stress in experimental model. Male Wistar rats (n = 40) were randomized in control (C), high-sucrose (HS), high-fat (HF), and high-fat with sucrose (HFHS) for 20 weeks. Nutritional, metabolic, hormonal, and biochemical profiles, as well as histological analysis of adipose and hepatic tissues were performed. Inflammation and oxidative stress were determined. HF model caused obesity and comorbidities as glucose intolerance and arterial hypertension. In relation to hormonal and biochemical parameters, there was no significant difference between the groups. All groups showed increased deposition of fat droplets in the hepatic tissue, even though adipocyte areas were similar. Biomarkers of oxidative stress in serum and adipose tissues were similar among the groups. HF model was effective in triggering associated obesity and comorbidities in male rats, but all hypercaloric diets were unable to promote oxidative stress and inflammation.

Resistance to obesity prevents obesity development without increasing spontaneous physical activity and not directly related to greater metabolic and oxidative capacity.

There are evidence that obese-resistant animals are more physically active, due to a higher rate of lipid oxidation. Efficiency in such pathways can favor greater spontaneous physical activity and, consequently, less body fat deposition. The aim of study was characterizing the nutritional profile and spontaneous physical activity in the condition of Resistance to Obesity (OR). Wistar rats were randomized into standard diet (SD; n = 50) and high-fat diet (HFD; n = 50) groups, after obesity induction, were redistributed into Control (C), False-control (FC), Propensity to obesity (OP) and OR, and then spontaneous physical activity was evaluated. Analyzed parameters: body mass (BM), epididymal (EF), retroperitoneal (RF), visceral (VF) and respective summations (∑), adiposity index (AI), nutritional, morphological, biochemical and metabolic parameters and protein quantification. The comparison of the groups was performed by ANOVA one or two factors, with 5% significance adopted. OP and FC presented high final MC values compared to C and OR. OR had lower EF, RF, VF, ∑ and IA compared to OP. OR had similar values to C and higher HDL than FC and OP. In GTT, OR and C presented similar values and both were lower than OP in the 30 minutes. OP promoted higher values than C for glycemic AUC. OR had higher PPARγ content than C and OP, as well as levels similar to C for leptin and insulin. Spontaneous physical activity did not differ between groups. The results were not enough to show that OR animals have greater lipid oxidative capacity, as well as greater spontaneous physical activity.

Acute effects of swimming aerobic exercise on contractility and intracellular calcium handling in isolated right ventricular cardiomyocytes / Efectos agudos del ejercicio de natación aeróbica sobre la contractilidad y el manejo del calcio intracelular en cardiomiocitos aislados del ventrículo derecho / Efeitos agudos do exercício aeróbio de natação na contratilidade e no transiente de cálcio intracelular em cardiomiócitos isolados do ventrículo direito

Objectives: The acute adjustments on the contractile function and the intracellular calcium (Ca2+) handling in the cardiomyocytes of the right ventricle (RV) after an acute aerobic exercise session are not known. Our aim was to investigate the acute responses of the contractile function and the intracellular Ca2+ handling in isolated RV cardiomyocytes after a swimming exercise session.Methods: Ten-week-old female Wistar rats were randomly allocated into two groups: control (C; n = 5) and exercise (Ex; n = 7). It was performed a swimming exercise session for 30 minutes. with an overload of 4% relative to the body weight attached to the tail. The rats were sacrificed after the exercise session for the analysis of the RV contractile function parameters and the intracellular Ca2+ handling by the isolated cardiomyocyte technique.Results: Body and heart weights, as well as sarcomere length were similar between the groups. Also, it was not observed differences between the groups for RV cardiomyocyte contractile parameters. However, the systolic and diastolic intracellular Ca2+ concentration was significantly lower in the Ex group compared to C with maintenance of Ca2+ amplitude.Conclusion: An acute swimming aerobic exercise session promotes cardiomyocyte contractility maintenance even with systolic and diastolic intracellular Ca2+ concentration reduced in the RV cardiomyocytes, reflecting an improvement in the intracellular Ca2+ handling.(AU)

Objetivos: se desconocen los ajustes agudos de la función contráctil y el manejo del calcio (Ca2+) intracelular en los cardiomiocitos del ventrículo derecho (VD) tras una sesión de ejercicio aeróbico agudo. Nuestro objetivo fue investigar las respuestas agudas de la función contráctil y el manejo del Ca2+ intracelular en cardiomiocitos aislados del VD después de una sesión de ejercicio de natación.Métodos: se asignaron al azar ratas Wistar hembra de diez semanas de edad en dos grupos: control (C; n = 5) y ejercicio (Ex; n = 7). Se realizó una sesión de ejercicios de natación durante 30 minutos con una sobrecarga del 4% con respecto al peso corporal adherido a la cola. Las ratas fueron sacrificadas después de la sesión de ejercicio para el análisis de los parámetros de la función contráctil del VD y el manejo del Ca2+ intracelular mediante la técnica de cardiomiocitos aislados.Resultados: los pesos corporales y cardíacos, así como la longitud del sarcómero, fueron similares entre los grupos. Además, no se observaron diferencias entre los grupos para los parámetros contráctiles de los cardiomiocitos del VD. Sin embargo, la concentración de Ca2+ intracelular sistólica y diastólica fue significativamente menor en el grupo Ex en comparación con C con el mantenimiento de la amplitud de Ca2+.Conclusión: Una sesión de ejercicio aeróbico de natación aguda promueve el mantenimiento de la contractilidad de los cardiomiocitos incluso con una concentración de Ca2+ intracelular sistólica y diastólica reducida en los cardiomiocitos del VD, lo que refleja una mejora en el manejo del Ca2+ intracelular.(AU)

Objetivo: os ajustes agudos na função contrátil e no transiente do cálcio (Ca2+) intracelular nos cardiomiócitos do ventrículo direito (VD) após uma sessão aguda de exercício aeróbio não são conhecidos. Desta forma objetivo foi investigar as respostas agudas da função contrátil e do no transiente Ca2+ intracelular em cardiomiócitos do VD isolados após uma sessão de exercício de natação.Métodos: Ratas Wistar com dez semanas de idade foram alocadas aleatoriamente em dois grupos: controle (C; n = 5) e exercício (Ex; n = 7). Foi realizada uma sessão de exercícios de natação por 30 minutos com uma sobrecarga de 4% em relação ao peso corporal preso à cauda. Os ratos foram sacrificados após a sessão de exercícios para análise dos parâmetros da função contrátil do VD e do transiente Ca2+ intracelular pela técnica de cardiomiócitos isolados.Resultados: Os pesos corporais e cardíacos, bem como o comprimento do sarcômero foram semelhantes entre os grupos. Além disso, não foram observadas diferenças entre os grupos para os parâmetros contráteis dos cardiomiócitos do VD. No entanto, a concentração de Ca2+ intracelular sistólica e diastólica foi significativamente menor no grupo Ex em comparação com C com manutenção da amplitude de Ca2+. Conclusão: Uma sessão aguda de exercício aeróbio de natação promove a manutenção da contratilidade dos cardiomiócitos mesmo com a concentração intracelular de Ca2+ sistólica e diastólica reduzida nos cardiomiócitos do VD, refletindo uma melhora no manuseio do Ca2+ intracelular.(AU)

High-Fat and Combined High-Fat and Sucrose Diets Promote Cardiac Oxidative Stress Independent of Nox2 Redox Regulation and Obesity in Rats.

BACKGROUND/AIMS: Oxidative stress is associated with cardiometabolic alterations, and the involvement of excess glucose and fatty acids has been demonstrated in this process. Thus, the aim of this study was to investigate the effects of different hypercaloric diets on cardiac oxidative stress. METHODS: Wistar rats were randomized into four groups: control (C), high-sucrose (HS), high-fat (HF), and high-fat with sucrose (HFS). Nutritional assessment, food profiles, histological analysis, comorbidities, and cardiovascular characteristics were determined. Cardiac oxidative stress was analyzed by malondialdehyde (MDA) and carbonylated proteins, and the cardiac protein expression levels of type 1 angiotensin receptor (AT-1), nicotinamide adenine dinucleotide phosphate oxidase 2 (Nox2), superoxide dismutase (SOD 1 e 2), glutathione peroxidase (GPX), and catalase (CAT) were determined by western blot. RESULTS: The HF group showed an increase in adiposity; however, it did not present adipocyte hypertrophy and comorbidities. Cardiac MDA and carbonylated protein levels were higher in the HF and HFS compared with the C group. The levels of oxidant and antioxidant proteins showed no difference between the groups. CONCLUSION: HF and HFS dietary interventions promoted cardiac oxidative stress, in the presence and absence of obesity, respectively. However, this process was neither mediated by the pro-oxidants AT1 and Nox2, nor by the quantitative reduction of antioxidant enzymes.

Digoxin Combined with Aerobic Interval Training Improved Cardiomyocyte Contractility.

Digoxin is a cardiotonic that increases the cardiac output without causing deleterious effects on heart, as well as improves the left ventricular performance during physical exercise. We tested whether the association between chronic digoxin administration and aerobic interval training (AIT) promotes beneficial cardiovascular adaptations by improving the myocardial contractility and calcium (Ca2+) handling. Male Wistar rats were randomly assigned to sedentary control (C), interval training (T), sedentary digoxin (DIGO) and T associated to digoxin (TDIGO). AIT was performed on a treadmill (1h/day, 5 days/week) for 60 days, consisting of successive 8-min periods at 80% and 20% of VO2máx for 2 min. Digoxin was administered by orogastric gavage for 60 days. Left ventricle samples were collected to analysis of Ca2+ handling proteins; contractility and Ca2+ handling were performed on isolated cardiomyocytes. TDIGO group had a greater elevation in fractional shortening (44%) than DIGO, suggesting a cardiomyocyte contractile improvement. In addition, T or TDIGO groups showed no change in cardiomyocytes properties after Fura2-acetoxymethyl ester, as well as in sarcoplasmic reticulum Ca2+-ATPase (SERCA2a), phospholamban and calcineurin expressions. The main findings indicate that association of digoxin and aerobic interval training improved the cardiomyocyte contractile function, but these effects seem to be unrelated to Ca2+ handling.

Short-Term Cigarette Smoking in Rats Impairs Physical Capacity and Induces Cardiac Remodeling.

Despite the strong evidence on the cardiac and renal damages after chronic exposure to cigarette smoke, there is a paucity of data on its short-term effects. The study evaluated the short-term effects of cigarette smoking on left ventricular (LV) remodeling, in vitro myocardial and renal function. Female Wistar rats were randomized to control (C) and cigarette smoking rats for eight weeks. Physical capacity was assessed using an adapted model of exhaustive swim; left ventricle (LV) morphology and function were also evaluated. Renal function was assessed by creatinine clearance and urine protein. The in vitro myocardial performance was analyzed in isolated papillary muscles. Rats exhibited reduced physical capacity after short-term cigarette smoking. Although there was no change on LV function, reduced chamber diameter was found in the smoking group associated with an increased LV wall thickness. There was augmented cardiac mass compared to C that was confirmed by increased cardiomyocyte nucleus volume, but in vitro myocardial performance and renal function were unchanged. A short-term cigarette smoking induces cardiac remodeling without abnormalities in function. The smoking group still preserved renal function and in vitro myocardial performance. However, the reduced physical capacity may suggest an impairment of the cardiac reserve.

Resistance training promotes reduction in Visceral Adiposity without improvements in Cardiomyocyte Contractility and Calcium handling in Obese Rats.

Resistance training (RT) improves the cardiomyocyte calcium (Ca2+) cycling during excitation-contraction coupling. However, the role of RT in cardiomyocyte contractile function associated with Ca2+ handling in obesity is unclear. Wistar rats were distributed into four groups: control, sedentary obese, control plus RT, and obesity plus RT. The 10-wk RT protocol was used (4-5 vertical ladder climbs, 60-second interval, 3× a week, 50-100% of maximum load). Metabolic, hormonal, cardiovascular and biochemical parameters were determined. Reduced leptin levels, epididymal, retroperitoneal and visceral fat pads, lower body fat, and adiposity index were observed in RT. Obesity promoted elevation of collagen, but RT did not promote modifications of LV collagen in ObRT. RT induced elevation in maximum rates of contraction and relaxation, and reduction of time to 50% relaxation. ObRT group did not present improvement in the cardiomyocyte contractile function in comparison to Ob group. Reduced cardiac PLB serine16 phosphorylation (pPLB Ser16) and pPLB Ser16/PLB ratio with no alterations in sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) and phospholamban (PLB) expression were observed in Ob groups. Resistance training improved body composition reduced fat pads and plasma leptin levels but did not promote positive alterations in cardiomyocyte contractile function, Ca2+ handling and phospholamban phosphorylation.

Hypercaloric diet models do not develop heart failure, but the excess sucrose promotes contractility dysfunction.

Several diseases are associated with excess of adipose tissue, and obesity is considered an independent risk factor for the development of cardiac remodeling and heart failure. Dietary aspects have been studied to elucidate the mechanisms involved in these processes. Thus, the purpose was the development and characterization of an obesity experimental model from hypercaloric diets, which resulted in cardiac remodeling and predisposition to heart failure. Thirty- day-old male Wistar rats (n = 52) were randomized into four groups: control (C), high sucrose (HS), high-fat (HF) and high-fat and sucrose (HFHS) for 20 weeks. General characteristics, comorbidities, weights of the heart, left (LV) and right ventricles, atrium, and relationships with the tibia length were evaluated. The LV myocyte cross sectional area and fraction of interstitial collagen were assayed. Cardiac function was determined by hemodynamic analysis and the contractility by cardiomyocyte contractile function. Heart failure was analyzed by pulmonary congestion, right ventricular hypertrophy, and hemodynamic parameters. HF and HFHS models led to obesity by increase in adiposity index (C = 8.3 ± 0.2% vs. HF = 10.9 ± 0.5%, HFHS = 10.2 ± 0.3%). There was no change in the morphological parameters and heart failure signals. HF and HFHS caused a reduction in times to 50% relaxation without cardiomyocyte contractile damage. The HS model presented cardiomyocyte contractile dysfunction visualized by lower shortening (C: 8.34 ± 0.32% vs. HS: 6.91 ± 0.28), as well as the Ca2+ transient amplitude was also increased when compared to HFHS. In conclusion, the experimental diets based on high amounts of sugar, lard or a combination of both did not promote cardiac remodeling with predisposition to heart failure under conditions of obesity or excess sucrose. Nevertheless, excess sucrose causes cardiomyocyte contractility dysfunction associated with alterations in the myocyte sensitivity to intracellular Ca2+.

Myocardial Dysfunction after Severe Food Restriction Is Linked to Changes in the Calcium-Handling Properties in Rats.

Severe food restriction (FR) impairs cardiac performance, although the causative mechanisms remain elusive. Since proteins associated with calcium handling may contribute to cardiac dysfunction, this study aimed to evaluate whether severe FR results in alterations in the expression and activity of Ca2+-handling proteins that contribute to impaired myocardial performance. Male 60-day-old Wistar-Kyoto rats were fed a control or restricted diet (50% reduction in the food consumed by the control group) for 90 days. Body weight, body fat pads, adiposity index, as well as the weights of the soleus muscle and lung, were obtained. Cardiac remodeling was assessed by morphological measures. The myocardial contractile performance was analyzed in isolated papillary muscles during the administration of extracellular Ca2+ and in the absence or presence of a sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) specific blocker. The expression of Ca2+-handling regulatory proteins was analyzed via Western Blot. Severe FR resulted in a 50% decrease in body weight and adiposity measures. Cardiac morphometry was substantially altered, as heart weights were nearly twofold lower in FR rats. Papillary muscles isolated from FR hearts displayed mechanical dysfunction, including decreased developed tension and reduced contractility and relaxation. The administration of a SERCA2a blocker led to further decrements in contractile function in FR hearts, suggesting impaired SERCA2a activity. Moreover, the FR rats presented a lower expression of L-type Ca2+ channels. Therefore, myocardial dysfunction induced by severe food restriction is associated with changes in the calcium-handling properties in rats.

High-Fat Diet-Induced Obesity Model Does Not Promote Endothelial Dysfunction via Increasing Leptin/Akt/eNOS Signaling.

Experimental studies show that the unsaturated high-fat diet-induced obesity promotes vascular alterations characterized by improving the endothelial L-arginine/Nitric Oxide (NO) pathway. Leptin seems to be involved in this process, promoting vasodilation via increasing NO bioavailability. The aim of this study was to test the hypothesis that unsaturated high-fat diet-induced obesity does not generate endothelial dysfunction via increasing the vascular leptin/Akt/eNOS signaling. Thirty-day-old male Wistar rats were randomized into two groups: control (C) and obese (Ob). Group C was fed a standard diet, while group Ob was fed an unsaturated high-fat diet for 27 weeks. Adiposity, hormonal and biochemical parameters, and systolic blood pressure were observed. Concentration response curves were performed for leptin or acetylcholine in the presence or absence of Akt and NOS inhibitor. Our results showed that an unsaturated high-fat diet promoted a greater feed efficiency (FE), elevation of body weight and body fat (BF), and an adiposity index, characterizing a model of obesity. However, comorbidities frequently associated with experimental obesity were not visualized, such as glucose intolerance, dyslipidemia and hypertension. The evaluation of the endothelium-dependent relaxation with acetylcholine showed no differences between the C and Ob rats. After NOS inhibition, the response was completely abolished in the Ob group, but not in the C group. Furthermore, Akt inhibition completely blunted vascular relaxation in the C group, but not in the Ob group, which was more sensitive to leptin-induced vascular relaxation. L-NAME incubation abolished the relaxation in both groups at the same level. Although Akt inhibitor pre-incubation reduced the leptin response, group C was more sensitive to its effect. In conclusion, the high-unsaturated fat diet-induced obesity improved the vascular reactivity to leptin and does not generate endothelial dysfunction, possibly by the increase in the vascular sensitivity to leptin and increasing NO bioavailability. Moreover, our results suggest that the increase in NO production occurs through the increase in NOS activation by leptin and is partially mediated by the Akt pathway.

Differential Effects of High Sugar, High Lard or a Combination of Both on Nutritional, Hormonal and Cardiovascular Metabolic Profiles of Rodents.

BACKGROUND: Dietary interventions in rodents can induce an excess of adipose tissue and metabolic disorders that resemble human obesity. Nevertheless, these approaches are not standardized, and the phenotypes may vary distinctly among studies. The aim of this study was to investigate the effects of different dietary interventions on nutritional, metabolic, biochemical, hormonal, and cardiovascular profiles, as well as to add to development and characterization of an experimental model of obesity. METHODS: Male Wistar rats were randomized into four groups: control diet (C), high-sugar (HS), high-fat (HF), or high-sugar and high-fat (HFHS). Weekly measurements of body weight, adiposity, area under the curve (AUC) for glucose, blood pressure (BP) and serum triglycerides, total cholesterol level, and leptin were performed. RESULTS: HF and HFHS models were led to obesity by increases in adipose tissue deposition and the adiposity index. All hypercaloric diets presented systolic BP increases. In addition, the AUC for glucose was greater in HF and HFHS than in C, and only the HF group presented hyperleptinemia. CONCLUSIONS: HF and HFHS diet approaches promote obesity and comorbidities, and thus represent a useful tool for studying human obesity-related disorders. By contrast, the HS model did not prove to be a good model of obesity.

Prevalência de Sobrepeso e Obesidade em Idosas do Centro de Convivência para a Terceira Idade de Vitória/ES / Prevalence of Overweight and Obesity among Aged Women from the Community Center for the Elderly in Vitória, ES, Brazil

Introdução: A senescência provoca alterações nas características morfofuncionais do indivíduo, bem como uma série de desordens nutricionais como sobrepeso e obesidade. Objetivo: O estudo avaliou a prevalência de sobrepeso e obesidade em idosas dos Centros de Convivência para a Terceira Idade de Vitória/ES. Material e Métodos: Foi realizado estudo de campo transversal e a amostra de conveniência foi composta por 135 idosas entre 60 e 79 anos. Foram mensuradas a massa corporal, estatura e dobras cutâneas para verificação do índice de massa corpórea (IMC) e percentual de gordura corporal (%GC), respectivamente. Para a comparação das características antropométricas entre os grupos etários de idosas foi utilizado o teste "t" de Student para amostras independentes. As prevalên-cias de sobrepeso e obesidade foram analisadas por meio do teste do qui-quadrado. O nível de significância adotado foi 5%. Resultados: Os resultados, com base no IMC, demonstram alta prevalência de obesidade (28% e 22% nos grupos etários de 60 a 69 e 70 a 79 anos, respectivamente) e sobrepeso (19% e 17% nos grupos etários de 60 a 69 e 70 a 79 anos, respectivamente), representando conjuntamente 42,96% de prevalência de excesso de peso na população estudada. Os resultados do %GC mostram alta prevalência de idosas agrupadas na classificação "ruim" e "muito ruim", representando 33% em ambos os grupos etários. Conclusão: O estudo mostra alta prevalência de sobrepeso e obesidade nas idosas, reforçando a necessidade de implementação de programas de reeducação alimentar e atividade física destinados à redução de gordura corporal. (AU)

Introduction: Senescence alters the morpho-functional characteristics of the individual as well as do a number of nutritional disorders, such as overweight and obesity. Objective: This study assessed the prevalence of overweight and obesity among aged women from the Community Center for the Elderly in Vitória, ES, Brazil. Materials and Method: A cross-sectional study was performed and a convenience sample was composed of 135 women aged between 60 and 79 years. Body weight, height and skinfold were recorded in order to check body mass index (BMI) and percentage of body fat (%BF), respectively. T test for independent samples was used to compare the anthropometric characteristics among age groups. The prevalence of overweight and obesity was analyzed using the chi-square test. The level of significance was 5%. Results: BMI values showed a high prevalence of obesity (28% and 22% in the age groups 60-69 and 70-79 years, respectively) and overweight (19% and 17% in the age groups 60-69 and 70 to 79 years, respectively), which consist together of an overweight prevalence of 42.96% in the studied population. The %BF results showed a high prevalence of elderly classified into the "poor" and "very poor" categories, representing 33% of the sample in both age groups. Conclusion: This study shows a high prevalence of overweight and obesity among aged women from the Community Center for the Elderly in Vitória, ES, which reinforces the need for implementation of nutritional and physical activity programs for body fat reduction. (AU)

DIGOXINA E VERAPAMIL INDUZEM HIPERTROFIA EM CARDIOMIÓCITOS DE RATOS SEDENTÁRIOS E/OU TREINADOS / DIGOXIN AND VERAPAMIL PROMOTE CARDIOMYOCYTE HYPERTROPHY IN SEDENTARY AND/OR TRAINED RATS / DIGOXINA Y VERAPAMILO INDUCEN HIPERTROFIA DE CARDIOMIOCITOS EN RATAS SEDENTARIAS Y/O ENTRENADAS

RESUMO Introdução: Cardiotônicos e bloqueadores de canais de cálcio são fármacos que alteram o Ca2+ intracelular e afetam o coração. Objetivo: Avaliar os efeitos da administração de verapamil e digoxina sobre a morfologia cardíaca de ratos submetidos ao treinamento intervalado (TAI). Métodos: Ratos Wistar machos divididos em seis grupos (N = 8): Controle, Digoxina (30,0 µg.kg-1/dia), Verapamil (5,0 mg.kg-1/dia), Treinado, Treinado+digoxina e Treinado+verapamil. O TAI foi realizado em esteira rolante (60 min/dia/60 dias) concomitantemente com a administração dos fármacos. Fragmentos do ventrículo esquerdo (VE) foram coletados para análise histológica. Resultados: A digoxina e o verapamil aumentaram a área total do VE (p < 0,002), capilares/área VE (p < 0,01) e área de cardiomiócitos (p < 2,8e-10), sendo que, nesta última variável, o verapamil promoveu efeito ainda maior que a digoxina. O TAI aumentou VE/PC (p < 4e-05), o diâmetro interno do VE (p < 2,7e-6), a área de cardiomiócitos (p < 1,8e-6) e reduziu o [Lac] (p < 2,6e-5). Houve interação entre TAI e fármacos na área total (p < 9,8e-5), capilares (p < 0,04), células/área (p < 0,004) e área de cardiomiócitos (p < 2e-16). Conclusão: A digoxina promoveu hipertrofia de cardiomiócitos e, quando associada ao TAI, potencializou a hipertrofia. O verapamil foi mais eficiente em aumentar a área de cardiomiócitos em comparação com a digoxina, porém somente de forma isolada.

ABSTRACT Introduction: Cardiotonics and calcium channel blockers are drugs that alter intracellular Ca2+ and can affect the heart. Objective: To evaluate the effects of administration of verapamil and digoxin on heart morphology of rats subjected to interval training (IT). Methods: Male Wistar rats were divided into groups (n = 8): Control, Digoxin (30.0µg.kg-1/day), Verapamil (5.0 mg.kg-1/day), Trained, Trained+digoxin and Trained+verapamil. The IT was performed on a treadmill (60 min/day/60 days) concurrently with the drugs administration. Fragments of the left ventricle (LV) were collected for histological analysis. Results: Digoxin and verapamil increased the total area of the LV (p<0.002), capillary/LV area (p<0.01) and cardiomyocytes area (p<2.8e-10), and in the latter variable, verapamil promoted even greater effect than digoxin. The IT increased LV/BW (p<4e-05), the inner diameter of the LV (p<2.7e-6), the area of cardiomyocytes (p<1.8e-6), and reduced the [Lac] (p<2.6e-5). There was interaction between IT and drugs in the total area (p<9.8e-5), capillaries (p<0.04), cell/area (p<0.004) and cardiomyocytes area (p <2.0e-16). Conclusions: Digoxin promoted cardiomyocyte hypertrophy and when associated with IT, potentiated the hypertrophy. Verapamil was more efficient in increasing the cardiomyocytes area compared with digoxin, but only when isolated.

RESUMEN Introducción: Cardiotónicos y bloqueadores de los canales de calcio son fármacos que alteran el Ca2+ intracelular y afectan al corazón. Objetivo: Evaluar los efectos de la administración de verapamilo y digoxina sobre la morfología del corazón de ratas sometidas a entrenamiento a intervalos (EI). Métodos: Ratas Wistar macho, divididas en seis grupos (N = 8): Control, Digoxina (30,0 µg.kg-1/día), Verapamilo (5,0 mg.kg-1/día), Entrenado, Entrenado+digoxina y Entrenado+verapamilo. El entrenamiento a intervalos se realizó en una cinta de correr (60 min/día/60 días), con la administración concomitante de fármacos. Se recogieron fragmentos del ventrículo izquierdo (VI) para el análisis histológico. Resultados: La digoxina y el verapamilo aumentaron el área total del VI (p < 0,002), capilares/área VI (p < 0,01) y el área de los cardiomiocitos (p < 2,8e-10) y, en esta última variable, el verapamilo promovió un efecto aún mayor que la digoxina. EI entrenamiento a intervalos aumentó VI/PC (p < 4e-05), el diámetro interior del VI (p < 2,7e-6), el área de los cardiomiocitos (p < 1,8e-6) y redujo el [Lac] (p < 2,6e-5). Hubo una interacción entre fármacos y el EI en el área total (p < 9,8e-5), capilares (p<0,04), células/área (p < 0,004) y el área de los cardiomiocitos (p < 2e-16). Conclusión: La digoxina promovió la hipertrofia de los cardiomiocitos y, cuando al asociarse con el EI, potenció la hipertrofia. El verapamilo fue más eficiente en el aumento de la zona de los cardiomiocitos en comparación con la digoxina, pero sólo de forma aislada.

HIPERTENSÃO EM ESTUDANTES DA REDE PÚBLICA DE VITÓRIA/ES: INFLUÊNCIA DO SOBREPESO E OBESIDADE / HYPERTENSION IN PUBLIC SCHOOL STUDENTS FROM VITÓRIA/ES: INFLUENCE OF OVERWEIGHT AND OBESITY / HIPERTENSIÓN EN ESTUDIANTES DE LA RED PÚBLICA DE VITÓRIA/ES: INFLUENCIA DEL SOBREPESO Y LA OBESIDAD

RESUMO Introdução: Pesquisas demonstram que a obesidade pode ter início na infância. Além disso, o excesso de peso presente em 50% na infância é fator preditor da obesidade na vida adulta. As consequências são preocupantes pela associação com diversas comorbidades, entre elas, a hipertensão arterial. Estudos mostram que crianças obesas apresentam risco superior de hipertensão arterial em relação às não obesas. Objetivo: Identificar a prevalência de hipertensão arterial e sua relação com o sobrepeso e obesidade em crianças e adolescentes estudantes da rede pública do município de Vitória, ES, Brasil. Foram estudados 477 alunos, com idade entre 7 e 17 anos, sendo 42,56% e 57,44% dos gêneros masculino e feminino, respectivamente, selecionados por meio de amostragem estratificada por conglomerados . Métodos: Na análise do perfil antropométrico foram utilizados: percentual de gordura por meio de medida de dobras cutâneas e índice de massa corporal (IMC). Além disso, foi realizada aferição da pressão arterial para classificação da hipertensão arterial. Resultados: Os resultados mostram nos estudantes de Vitória, ES, com sobrepeso, valores pressóricos elevados (limítrofes e hipertensos 1 e 2), representando nos gêneros masculino e feminino 21,1% (PAS: 112 ± 10,4 mmHg e PAD: 65,6 ± 8,91 mmHg) e 19,2% (PAS: 108 ± 12,1 mmHg e PAD: 65,6 ± 8,90 mmHg), respectivamente. No entanto, nos estudantes obesos, a prevalência foi maior, abrangendo 26,3% (PAS: 113 ± 11,3 mmHg e PAD: 67,8 ± 10,1 mmHg) no gêneros masculino e 25% (PAS: 108 ± 14,4 mmHg e PAD: 68,3 ± 10,2 mmHg) no feminino. Conclusão: Os achados relatados neste estudo mostram altos índices de crianças e adolescentes acometidos tanto por excesso de peso quanto pela hipertensão arterial. Estes resultados sugerem a implementação de medidas preventivas e de tratamento dos fatores de risco cardiovascular em crianças e adolescentes do município de Vitória, ES.

ABSTRACT Introduction: Researches show that obesity can start in childhood. Furthermore, the excess of body weight, present at 50% in childhood, is a predictor of obesity in adulthood. Consequences are alarming due to the association with several comorbidities, among them, hypertension. Studies show that obese children are at higher risk for hypertension compared to non-obese population. Objective: To identify the prevalence of hypertension and its relation to overweight and obesity in children and adolescents from public schools of the municipality of Vitória, ES, Brazil. We studied 477 students, aged between 7 and 17 years, 42.56% male and 57.44% female, who were randomly selected by stratified cluster sample. Methods: In the analysis of anthropometric profile the following were used: percentage of body fat by measuring skinfold thickness and body mass index (BMI). Moreover, measurement of blood pressure was performed to classify the arterial hypertension. Results: The results show in overweight students of Vitória, ES, high blood pressure values (pre-hypertension and stages 1 and 2 hypertension), representing 21.1% in males (SBP: 112 ± 10.4 mmHg and DBP: 65.6. ± 8.91 mmHg) and 19.2% in females (SBP: 108 ± 12.1 mmHg and DBP: 65.6 ± 8.90 mmHg), respectively. However, in obese students, the prevalence was higher, comprising 26.3% in males (SBP: 113 ± 11.3 mmHg and DBP: 67.8 ± 10.1 mmHg) and 25% in females (SBP: 108 ± 14.4 mmHg and DBP: 68.3 ± 10.2 mmHg). Conclusion: The findings reported in this study show high rates of children and adolescents affected by both overweight and hypertension. These results suggest the implementation of preventive measures and treatment of cardiovascular risk factors in children and adolescents from the municipality of Vitória, ES.

RESUMEN Introducción: La investigación ha demostrado que la obesidad puede comenzar en la infancia. Además, el peso excesivo presente en 50% de los niños en edad escolar es un factor predictivo de la obesidad en la vida adulta. Las consecuencias son preocupantes por la asociación con varias comorbilidades, entre ellas, la hipertensión arterial. Los estudios demuestran que los niños obesos tienen un mayor riesgo de hipertensión en comparación con los no obesos. Objetivo: Identificar la prevalencia de la hipertensión y su relación con el sobrepeso y la obesidad en niños y adolescentes de la red pública municipal de Vitória, ES, Brazil. Se estudiaron 477 estudiantes, con edades comprendidas entre los 7 y 17 años, 42,56% y 57,44%, hombres y mujeres, respectivamente, seleccionados mediante muestreo por conglomerado estratificado. Métodos: Fueron usados en el análisis del perfil antropométrico: porcentaje de grasa mediante la medición de pliegues cutáneos y el índice de masa corporal (IMC). Además, se realizó la medición de la presión arterial para la clasificación de la hipertensión arterial. Resultados: Los resultados muestran en los estudiantes de Vitória, ES, con sobrepeso, valores de presión sanguínea elevados (borderline e hipertensos 1 y 2), en representación de los hombres y mujeres 21,1% (PAS: 112 ± 10,4 mmHg y PAD: 65,6 ± 8,91 mmHg) y 19,2% (PAS: 108 ± 12,1 mmHg y la PAD: 65,6 ± 8,90 mm Hg), respectivamente. Sin embargo, en los estudiantes obesos, la prevalencia fue mayor, comprendiendo 26,3% (PAS: 113 ± 11,3 mmHg y PAD: 67,8 ± 10,1 mmHg) en el sexo masculino y 25% (PAS: 108 ± 14,4 mmHg y la PAD: 68,3 ± 10,2 mmHg) en el sexo femenino. Conclusión: Los resultados reportados en este estudio muestran altos índices de niños y adolescentes afectados por tanto el sobrepeso como por la presión arterial alta. Estos resultados sugieren la aplicación de medidas preventivas y de tratamiento de los factores de riesgo cardiovascular en niños y adolescentes en el municipio de Vitória, ES.