Effect of aerobic and resistance exercise training on endothelial function in individuals with overweight and obesity: a systematic review with meta-analysis of randomized clinical trials.

The objective of this systematic review was to examine the effects of exercise training on endothelial function in individuals with overweight and obesity. Our review study included only randomized controlled trials (RCTs) involving adults (≥ 18 years of age) with body mass index (BMI) ≥ 25.0 kg/m2. Our search was conducted in the electronic bases MEDLINE (PubMed), Cochrane, LILACS and EMBASE and in the gray literature. We performed random-effects analyses for effect estimates and used 95% prediction intervals (95% PI) for estimating the uncertainty of the study results. There were selected 10 RCTs involving 14 groups (n = 400). The quality assessment of studies using Cochrane risk-of-bias 2 (RoB 2) tool identified some concerns. Exercise training resulted in improved flow-mediated dilation (FMD) in individuals with overweight and obesity (p < 0.001) compared to the no-exercise control group. This effect of training modalities on FMD was seen for aerobic training (p < 0.001) but not for resistance training (p = 0.051). There was no difference in FMD in response to exercise training by BMI classification (overweight, obesity, overweight + obesity), p = 0.793. The present results are consistent with the notion that aerobic exercise training elicits favorable adaptations in endothelial function in individuals with overweight and obesity. Our findings should be interpreted with caution because of the small number of studies included in this review.

Set7 deletion attenuates isoproterenol-induced cardiac fibrosis and delays cardiac dysfunction.

Cardiovascular diseases are the main cause of death worldwide. Recent studies have revealed the influence of histone-modifying enzymes in cardiac remodeling and heart dysfunction. The Set7 methyltransferase regulates the expression of several genes through the methylation of histones and modulates the activity of non-histone proteins. However, the role of Set7 in cardiac remodeling and heart dysfunction remains unknown. To address this question, wild-type (WT) and Set7 knockout (KO) male mice were injected with isoproterenol or saline. WT mice injected with isoproterenol displayed a decrease in Set7 activity in the heart. In addition, WT and Set7 KO mice injected with isoproterenol exhibited cardiac hypertrophy. Interestingly, Set7 deletion exacerbated cardiac hypertrophy in response to isoproterenol but attenuated myocardial fibrosis. Echocardiograms revealed that WT mice injected with isoproterenol had lowered ejection fractions and fractional shortening, and increased E'-wave deceleration time and E/A ratio compared with their controls. Conversely, Set7 KO mice did not show alteration in these parameters in response to isoproterenol. However, prolonged exposure to isoproterenol induced cardiac dysfunction both in WT and Set7 KO mice. Both isoproterenol and Set7 deletion changed the transcriptional profile of the heart. Moreover, Set7 deletion increased the expression of Pgc1α and mitochondrial DNA content in the heart, and reduced the expression of cellular senescence and inflammation markers in response to isoproterenol. Taken together, our data suggest that Set7 deletion attenuates isoproterenol-induced myocardial fibrosis and delays heart dysfunction, suggesting that Set7 plays an important role in cardiac remodeling and dysfunction in response to stress.

Ventilatory Muscle Training for Early Cardiac Rehabilitation Improved Functional Capacity and Modulated Vascular Function of Individuals Undergoing Coronary Artery Bypass Grafting: Pilot Randomized Clinical Trial.

Background: Cardiac rehabilitation with aerobic exercises is the first strategy for nonpharmacological treatment in the postoperative period of individuals undergoing coronary artery bypass grafting (CABG) to improve functional capacity and vascular health. However, other exercise modalities remain uncertain regarding the same benefits. Objectives: Evaluation of the effect of different modalities of exercise, such as early cardiac rehabilitation on subjects submitted to CABG in the six-minute walk test (6-MWT) and on the percentage of flow-mediated dilatation (FMD) of the brachial artery. Methods: A randomized clinical trial in which 15 patients (62.7 ± 6.7 years) who underwent CABG were randomly assigned to the following groups: isometric (IG, Handgrip Jamar®), ventilatory muscle training (VG, PowerBreathe®) and control (CG, conventional respiratory and motor physiotherapy). All patients were attended to physically twice a day (20 min/session) for a consecutive week after the CABG (hospital admission). Functional capacity was assessed by 6-MWT and endothelial function was assessed through the technique of FMD, before and after (~7 days) admission to CABG. The doppler ultrasound videos were analyzed by Cardiovascular Suite® software (Quipu, Pisa, Italy) to measure %FMD. Statistics: Generalized estimation equation, followed by Bonferroni post hoc (p < 0.05). Results: Systolic, diastolic and mean arterial pressure (SBP/DBP/MAP, respectively) were 133, 76 and 95 mmHg. The groups presented walking meters (m) distance before and after intervention of: IGbasal 357.80 ± 47.15 m vs. IGpost 306.20 ± 61.63 m, p = 0.401 (+51 m); VGbasal 261.50 ± 19.91 m vs. VGpost 300.75 ± 26.29 m, p = 0.052 (+39 m); CG basal 487.83 ± 83.23 m vs. CGpost 318.00 ± 31.08, p = 0.006 (−169 m). %FMD before and after intervention was IGbasal 10.4 ± 4.8% vs. IGpost 2.8 ± 2.5%, p = 0.152; VGbasal 9.8 ± 5.1% vs. VGpost 11.0 ± 6.1%, p = 0.825; CGbasal 9.2 ± 15.8% vs. CGpost 2.7 ± 2.6%, p = 0.710 and resting mean basal blood flow was IGbasal 162.0 ± 55.0 mL/min vs. IGpost 129.9 ± 63.7 mL/min, p = 0.662; VGbasal 83.74 ± 12.4 mL/min vs. VGpost 58.7 ± 17.1 mL/min, p = 0.041; CGbasal 375.6 ± 183.7 mL/min vs. CGpost 192.8 ± 115.0 mL/min, p = 0.459. Conclusions: Ventilatory muscle training for early cardiac rehabilitation improved acute functional capacity and modulated mean flow of individuals undergoing CABG.

Photobiomodulation therapy preconditioning modifies nitric oxide pathway and oxidative stress in human-induced pluripotent stem cell-derived ventricular cardiomyocytes treated with doxorubicin.

Doxorubicin (DOX) is an anthracycline antibiotic that exhibits high heart toxicity. Human-induced pluripotent stem cell-derived ventricular cardiomyocytes (hiPSC-vCMs) are important in vitro models for testing drug cardiotoxicity. Photobiomodulation therapy (PBMT) is a non-invasive therapy that stimulates cells growth and self-repair using light irradiation. This study aimed to investigate the in vitro effects of PBMT preconditioning on cardiotoxicity induced by DOX. HiPSC-vCMs were treated with PBMT for 500 s, followed by the addition of 2 µM DOX. LED irradiation preconditioning parameters were at 660 nm with an irradiance of 10 mW/cm2, performing 5 J/cm2, followed by 24-h DOX exposure (2 µM). Human iPSC-vCMs treated with 2 µM DOX or irradiated with PBMT composed the second and third groups, respectively. The control group did neither receive PBMT preconditioning nor DOX and was irradiated with a white standard lamp. Cells from all groups were collected to perform mRNA and miRNA expressions quantification. PBMT, when applied before the DOX challenge, restored the viability of hiPSC-vCMs and reduced ROS levels. Although downregulated by DOX, myocardial UCP2 mRNA expression presented marked upregulation after PBMT preconditioning. Expression of eNOS and UCP2 mRNA and NO production were decreased after DOX exposure, and PBMT preconditioning before the DOX challenge reversed these changes. Moreover, our data indicated that PBMT preconditioning lowered the miR-24 expression. Our data suggested that PBMT preconditioning ameliorated in vitro DOX-induced cardiotoxicity on transcription level, restoring NO levels and reducing oxidative stress.

Effects of autonomic nervous system activation on endothelial function in response to acute exercise in hypertensive individuals: study protocol for a randomized double-blind study.

BACKGROUND: Arterial hypertension has a direct association with endothelial dysfunction and major cardiovascular events. There is evidence showing the benefits of aerobic exercise on flow-mediated dilation (FMD) in hypertensive individuals but little is known about the effect of autonomic nervous system (ANS) activation on FMD of the brachial artery in response to different types of exercise in this specific population. This study aims to examine the effects of ANS activation on FMD of the brachial artery in response to exercise in hypertensive individuals following a session of different types of exercise including aerobic exercise (AE), resistance exercise (RE), or combined exercise (CE). METHODS: Thirty-nine hypertensive volunteers aged 35 to 55 years will be randomly assigned to two exercise sessions: AE (40 min on a cycle ergometer at 60% of HR reserve), RE (4 lower limb sets with 12 repetitions at 60% 1-RM for 40 min), or CE (RE for 20 min + AE for 20 min). Each exercise group will be randomized to receive either an α1-adrenergic blocker (doxazosin 0.05 mg/kg-1) or placebo. Ultrasound measurement of FMD is performed 10 min before and 10, 40, and 70 min after exercise. ANS activation is monitored using a Finometer and measurements are taken during 10 min before each FMD assessment. Arterial stiffness is assessed by pulse wave velocity (PWV) analysis using a Complior device. DISCUSSION: We expect to demonstrate the effect of ANS activation on FMD of the brachial artery in hypertensive individuals in response to different types of exercise. This study may give some insight on how to improve exercise prescription for hypertension management. TRIAL REGISTRATION: https://clinicaltrials.gov and ID "NCT04371757". Registered on May 1, 2020.

Acute renal denervation normalizes aortic function and decreases blood pressure in spontaneously hypertensive rats.

Mechanisms involved in the acute responses to renal denervation (RDN) have yet to be fully understood. We assessed urinary volume, autonomic control and aorta vascular reactivity after acute RDN. Male normotensive Wistar rats and spontaneously hypertensive rats (SHR) were divided into normotensive + RDN (ND) or sham surgery (NS), and hypertensive + RDN (HD) or sham surgery (HS). Metabolic parameters and hemodynamic measurements were recorded 72h and 4 days after intervention, respectively. Aortic rings were studied 7 days post RDN in an isometric myograph. Concentration-response curves to phenylephrine, sodium nitroprusside and acetylcholine (10-10-10-5 M) were performed. Two-way ANOVA was used for group comparisons and differences reported when p < 0.05. Results are presented as mean ± SEM. Urinary volume was 112% higher in HD vs. HS (HS = 14.94 ± 2.5 mL; HD = 31.69 ± 2.2 mL) and remained unchanged in normotensive rats. Systolic BP was lower in HD rats (HS = 201 ± 12 vs. HD = 172 ± 3 mmHg) without changes in normotensive group. HD group showed increased HF and LF modulation (HS = 5.8 ± 0.7 ms2 vs. HD = 13.4 ± 1.4 ms2; HS = 3.5 ± 0.7 ms2 vs. HD = 10.5 ± 1.7 ms2, respectively). RDN normalized vascular reactivity in HD rats and increased phenylephrine response in ND rats. Acute fall in BP induced by RDN is associated with increased urinary volume, which in turn may also have contributed to functional changes of the aorta.

A randomized controlled trial to reduce sedentary time in rheumatoid arthritis: protocol and rationale of the Take a STAND for Health study.

BACKGROUND: Patients with rheumatoid arthritis spend most of their daily hours in sedentary behavior (sitting), a predisposing factor to poor health-related outcomes and all-cause mortality. Interventions focused on reducing sedentary time could be of novel therapeutic relevance. However, studies addressing this topic remain scarce. We aim to investigate the feasibility and efficacy of a newly developed intervention focused on reducing sedentary time, and potential clinical, physiological, metabolic and molecular effects in rheumatoid arthritis. METHODS: The Take a STAND for Health study is a 4-month, parallel-group, randomized controlled trial, in which postmenopausal patients with rheumatoid arthritis will set individually tailored, progressive goals to replace their sedentary time with standing and light-intensity activities. Patients will be recruited from the Clinical Hospital (School of Medicine, University of Sao Paulo) and will be assessed at baseline and after a 4-month follow up. Outcomes will include objectively measured sedentary behavior (primary outcome) and physical activity levels, clinical parameters, anthropometric parameters and body composition; aerobic fitness, muscle function, blood pressure, cardiovascular autonomic function, vascular function and structure, health-related quality of life, and food intake. Blood and muscle samples will be collected for assessing potential mechanisms, through targeted and non-targeted approaches. DISCUSSION: Findings will be of scientific and clinical relevance with the potential to inform new prescriptions focused on reducing sedentary behavior, a modifiable risk factor that thus far has been overlooked in patients with rheumatoid arthritis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03186924. Registered on 14 June 2017.

Safety and efficacy of baroreflex activation therapy for heart failure with reduced ejection fraction: a rapid systematic review.

To retrieve and assess the available data in the literature about the safety and efficacy of baroreflex activation therapy (BAT) in heart failure with reduced ejection fraction (HFrEF) patients, through a rapid systematic review of clinical studies. Rapid systematic review of literature. Searched electronic databases included PubMed, EMBASE, CENTRAL, Scopus, and Web of Science using Mesh and free terms for heart failure and BAT. No language restriction was used for the searches. We included full peer reviewed publications of clinical studies (randomized or not), including patients with HFrEF undergoing BAT, with or without control group, assessing safety and efficacy outcomes. One reviewer conducted the analysis of the selected abstracts and the full-text articles, performed data extraction, and evaluated the methodological quality of the selected articles. The methodological quality was assessed according to the Cochrane Collaboration instruments. A descriptive summary of the results is provided. Of the 441 citations screened, 10 publications were included (three were only conference abstracts), reporting data from three studies. Only one study was a randomized clinical trial. Two studies reported a 6 month following, and the other study analysed outcomes up to 41 months. The procedure seems to be safe when performed by a well-trained multi-professional team. An 86% rate of system and procedure-related complication-free was reported, with no cranial nerve injuries. Improvements in New York Heart Association class of heart failure, quality of life, 6 min walk test, and hospitalization rates, as well as in muscle sympathetic nerve activity. No meta-analysis was conducted because of the lack of homogeneity across studies; the results from each study are reported individually. BAT procedure seems to be safe if appropriate training is provided. Improvements in clinical outcomes were described in all included studies. However, several limitations do not allow us to make conclusive statements on the efficacy of BAT for HFrEF. New well-designed trials are still needed.

Alamandine attenuates arterial remodelling induced by transverse aortic constriction in mice.

Aims: The renin-angiotensin system (RAS) plays an important role in the pathophysiology of vascular diseases, especially as a mediator of inflammation and tissue remodelling. Alamandine (Ala1-angiotensin-(1-7)) is a new biologically active peptide from the RAS, interacting with Mas-related G-protein-coupled receptor member D. Although a growing number of studies reveal the cardioprotective effects of alamandine, there is a paucity of data on its participation in vascular remodelling associated events. In the present study, we investigated the effects of alamandine on ascending aorta remodelling after transverse aortic constriction (TAC) in mice. Methods and results: C57BL/6J male mice were divided into the following groups: Sham (sham-operated), TAC (operated) and TAC+ALA (operated and treated with alamandine-HPßCD (2-Hydroxypropyl-ß-cyclodextrin), 30 µg/kg/day, by gavage). Oral administration of alamandine for 14 days attenuated arterial remodelling by decreasing ascending aorta media layer thickness and the cells density in the adventitia induced by TAC. Alamandine administration attenuated ascending aorta fibrosis induced by TAC, through a reduction in the following parameters; total collagen deposition, expression collagen III and transforming growth factor-ß (TGF-ß) transcripts, matrix metalloproteinases (MMPs) activity and vascular expression of MMP-2. Importantly, alamandine decreased vascular expression of proinflammatory genes as CCL2, tumour necrosis factor α (TNF-α) and interleukin-1ß (IL-1ß), and was able to increase expression of MRC1 and FIZZ1, pro-resolution markers, after TAC surgery. Conclusion: Alamandine treatment attenuates vascular remodelling after TAC, at least in part, through anti-fibrotic and anti-inflammatory effects. Hence, this work opens new avenues for the use of this heptapeptide also as a therapeutic target for vascular disease.

Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 ) supplementation on experimental hyperhomocysteinemia (Hhe) induced by homocysteine thiolactone (HcyT). Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6 ). On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6 ). After 60 days of treatment, homocysteine (Hcy), cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2)-like 2 (NRF2) and glutathione S-transferase (GST) immunocontent, and superoxide dismutase (SOD), catalase (CAT), and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62%) in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51%) in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17%) in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53%) compared to the CB6 group. Ejection fraction (EF) was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI) (r = 0.71; P = 0.06) and E/A ratio (r = 0.6; P = 0.01), and between EF and GST activity (r = 0.62; P = 0.02). Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters (AU)

Sevoflurane preconditioning during myocardial ischemia-reperfusion reduces infarct size and preserves autonomic control of circulation in rats.

PURPOSE: To investigate the myocardial ischemia-reperfusion with sevoflurane anesthetic preconditioning (APC) would present beneficial effects on autonomic and cardiac function indexes after the acute phase of a myocardial ischemia-reperfusion. METHODS: Twenty Wistar rats were allocated in three groups: control (CON, n=10), myocardial infarction with sevoflurane (SEV, n=5) and infarcted without sevoflurane (INF, n=5). Myocardial ischemia (60 min) and reperfusion were performed by temporary coronary occlusion. Twenty-one days later, the systolic and diastolic function were evaluated by echocardiography; spectral analysis of the systolic arterial pressure (SAPV) and heart rate variability (HRV) were assessed. After the recording period, the infarct size (IS) was evaluated. RESULTS: The INF group presented greater cardiac dysfunction and increased sympathetic modulation of the SAPV, as well as decreased alpha index and worse vagal modulation of the HRV. The SEV group exhibited attenuation of the systolic and diastolic dysfunction and preserved vagal modulation (square root of the mean squared differences of successive R-R intervals and high frequency) of HRV, as well as a smaller IS. CONCLUSION: Sevoflurane preconditioning better preserved the cardiac function and autonomic modulation of the heart in post-acute myocardial infarction period.

Sevoflurane preconditioning during myocardial ischemia-reperfusion reduces infarct size and preserves autonomic control of circulation in rats

ABSTRACT PURPOSE: To investigate the myocardial ischemia-reperfusion with sevoflurane anesthetic preconditioning (APC) would present beneficial effects on autonomic and cardiac function indexes after the acute phase of a myocardial ischemia-reperfusion. METHODS: Twenty Wistar rats were allocated in three groups: control (CON, n=10), myocardial infarction with sevoflurane (SEV, n=5) and infarcted without sevoflurane (INF, n=5). Myocardial ischemia (60 min) and reperfusion were performed by temporary coronary occlusion. Twenty-one days later, the systolic and diastolic function were evaluated by echocardiography; spectral analysis of the systolic arterial pressure (SAPV) and heart rate variability (HRV) were assessed. After the recording period, the infarct size (IS) was evaluated. RESULTS: The INF group presented greater cardiac dysfunction and increased sympathetic modulation of the SAPV, as well as decreased alpha index and worse vagal modulation of the HRV. The SEV group exhibited attenuation of the systolic and diastolic dysfunction and preserved vagal modulation (square root of the mean squared differences of successive R-R intervals and high frequency) of HRV, as well as a smaller IS. CONCLUSION: Sevoflurane preconditioning better preserved the cardiac function and autonomic modulation of the heart in post-acute myocardial infarction period.

Um novo olhar da retinopatia hipertensiva: a aplicação prática de novas tecnologias / A new look at hypertensive retinopathy: the practical application of new technologies

O exame de fundo de olho tem importância histórica e mantém sua relevância nos dias atuais, por possibilitar de maneira não invasiva, observar e avaliar o “interior” do corpo humano, além de ser um importante marcador de lesão de órgão-alvo em hipertensos. O surgimento de tecnologias de aquisição de imagens digitais permitiu acessar o fundo de olho de maneira mais simples, com grande definição, muitas vezes não necessitando dilatação da pupila. Isso tornou a observação do fundo de olho, que outrora era realizada apenas por pessoas com treinamento especial, fosse feita com extrema facilidade e quase sem treinamento. Estas “facilidades” permitiram que inúmeros artigos científicos fossem realizados, estabelecendo características do fundo de olho como relevante marcador de lesão de órgão-alvo em hipertensos. A incorporação de tecnologias virtuais na prática da medicina facilitará o acesso dos pacientes, reduzirá custos e certamente irá revolucionar a relação médico-paciente nos próximos anos.

Eye fundus examination is of historical importance, and maintains its relevance nowadays, by enabling non-intrusive observation and evaluation “inside” the human body, as well as being an important marker of target organ damage in hypertensive patients. The emergence of technologies for digital image acquisition have enabled easier access to the eye fundus, with greater definition, and often without having to dilate the pupil. As a result, eye fundusexamination, once carried out only by people with special training, is now performed with extreme ease and almost no training. These “facilities” have led to numerous scientific articles, establishing the characteristics of the eye fundus as a relevant marker of target organ damage in hypertensive patients. The incorporation of virtual technologies into the practiceof medicine will facilitate patient access, reduce costs, and without doubt, revolutionize the doctor-patient relationship in the coming years.

Effect of high-fat diet upon inflammatory markers and aortic stiffening in mice.

Changes in lifestyle such as increase in high-fat food consumption are an important cause for vascular diseases. The present study aimed to investigate the involvement of ACE and TGF- ß in the aorta stiffness induced by high-fat diet. C57BL/6 male mice were divided in two groups according to their diet for 8 weeks: standard diet (ST) and high-fat diet (HF). At the end of the protocol, body weight gain, adipose tissue content, serum lipids and glucose levels, and aorta morphometric and biochemical measurements were performed. Analysis of collagen fibers by picrosirius staining of aorta slices showed that HF diet promoted increase of thin (55%) and thick (100%) collagen fibers deposition and concomitant disorganization of these fibers orientations in the aorta vascular wall (50%). To unravel the mechanism involved, myeloperoxidase (MPO) and angiotensin I converting enzyme (ACE) were evaluated by protein expression and enzyme activity. HF diet increased MPO (90%) and ACE (28%) activities, as well as protein expression of ACE. TGF-ß was also increased in aorta tissue of HF diet mice after 8 weeks. Altogether, we have observed that the HF diet-induced aortic stiffening may be associated with increased oxidative stress damage and activation of the RAS in vascular tissue.

Treinamento físico aeróbio previne à hipertrofia cardíaca patológica e melhora a função diastólica em ratos Zucker obesos / Aerobic exercise training revert pathologic cardiac hypertrophy and improves the diastolic function in obese Zucker rats

A obesidade é uma patologia diretamente relacionada com o desenvolvimento de doenças cardiovasculares. Por outro lado, o treinamento físico aeróbio atenua o desenvolvimento da obesidade e promove benefícios cardíacos em obesos. Dessa forma, nosso objetivo foi investigar se a obesidade altera a função cardíaca e se sua associação com o treinamento físico aeróbio promove melhora na função cardíaca em ratos Zucker obesos. Os ratos Zucker foram divididos da seguinte forma: grupo magro (GM), grupo obeso (GO), grupo magro treinado (GMTR) e grupo obeso treinado (GOTR). O protocolo de treinamento aeróbio de natação foi realizado por um período de 10 semanas com cinco sessões semanais de 60 minutos de duração. A frequência cardíaca de repouso, a pressão arterial sistólica, a hipertrofia e função cardíaca foram avaliadas no final do período de treinamento físico. Ambos os grupos treinados apresentaram uma queda de 12 por cento da frequência cardíaca de repouso, quando comparado com seus respectivos controles. Ainda, nossos resultados demonstraram que o treinamento aeróbio reduziu o aumento da massa cardíaca em 13 por cento e melhorou a função diastólica na obesidade em 43 por cento. Em conclusão, nossos dados demonstraram que o treinamento físico aeróbio reverteu os prejuízos cardíacos causados pela obesidade.

Obesity is profoundly involved in cardiovascular diseases. On the other hand, aerobic exercise training (EXT) attenuates obesity and promotes cardiac benefits in obese individuals. Therefore, the aim of this study was to investigate if obesity alters the cardiac function and whether its association with exercise training can improve cardiac function in an obese Zucker rat strain. The rats were divided in the following groups: Lean Zucker rats (LZR); lean Zucker rats plus exercise training (LZR+EXT); obese Zucker rat (OZR) and obese Zucker rat plus exercise training (OZR+EXT). EXT consisted of 10 weeks swimming sessions of 60 min, 5 days/week. At the end of the training protocol we evaluated heart rate (HR), systolic blood pressure (SBP), cardiac hypertrophy (CH) and function. The trained groups LZR+EXT and OZR+EXT showed a 12 percent lower resting HR when compared with theirs respective controls. In addition, our results showed that exercise training reduced the cardiac mass by 13 percent and improved the diastolic function by 43 percent in the obese trained group when compared with the obese untrained. In conclusion, aerobic exercise training reverts the cardiac injuries in obese Zucker rats.

A associação de esteroide anabolizante ao treinamento físico aeróbio leva a alterações morfológicas cardíacas e perda de função ventricular em ratos / Association between anabolic steroids and aerobic physical training leads to cardiac morphological alterations and loss of ventricular function in rats

INTRODUÇÃO: O esteroide anabolizante (EA) associado ao treinamento físico induz mudança da hipertrofia cardíaca (HC) fisiológica para patológica. Entretanto, esses trabalhos foram realizados com atletas de força, sendo os efeitos do EA associados ao treinamento aeróbio poucos conhecidos. Com isso, o objetivo do estudo foi avaliar os efeitos do treinamento aeróbio e dos EA sobre a estrutura e função cardíaca. MÉTODOS: Foram utilizados 28 ratos Wistar divididos em quatro grupos: sedentários controle (SC), sedentários anabolizante (SA), treinados controle (TC) e treinado anabolizante (TA). O EA foi administrado duas vezes por semana (10mg/kg/ semana). O treinamento físico de natação foi realizado durante 10 semanas, cinco sessões semanais. Foram avaliadas a pressão arterial e frequência cardíaca por pletismografia de cauda, função ventricular por ecocardiografia, diâmetro dos cardiomiócitos e fração volume de colágeno por métodos histológicos. RESULTADOS: Não foram observadas diferenças na PA. O grupo TC apresentou redução da frequência cardíaca de repouso após o período experimental, o que não ocorreu no grupo TA. Foram observadas HC de 38 por cento no grupo SA, 52 por cento no grupo TC e de 64 por cento no grupo TA em relação ao grupo SC. O grupo TA apresentou diminuição da função diastólica em relação aos outros grupos. Os grupos treinados apresentaram aumentos significantes no diâmetro dos cardiomiócitos. Os grupos SA e TA apresentaram aumento na fração volume de colágeno em relação aos grupos SC e TC. CONCLUSÃO: Os resultados apresentados mostram que o treinamento físico de natação induz a HC, principalmente pelo aumento do colágeno intersticial, o que pode levar a prejuízos da função diastólica.

INTRODUCTION: Anabolic-androgen steroids (AAS) associated with physical training induce changes from physiological cardiac hypertrophy (CH) to pathological hypertrophy. However, these studies were performed with strength athletes, and the AAS effects associated with aerobic training are still poorly understood. Thus, the aim of this study was to evaluate the effects of aerobic training and AAS on the cardiac structure and function. METHODS: 28 Wistars rats divided in 4 groups were used: sedentary control (SC), sedentary anabolic (SA), trained control (TC) and trained anabolic (TA). The AAS was administered twice a week (10mg/Kg/week). The swimming training was conducted 5 sessions per week during 10 weeks. We evaluated blood pressure and heart rate by tail plethysmography, ventricular function by echocardiography, cardiomyocyte diameter and collagen volumetric fraction by histological methods. RESULTS: There were no differences in BP. TC group showed reduction in rest heart rate after the experimental period, which did not occur in TA group. CH of 38 percent in SA group; 52 percent in TC group and 64 percent in TA group compared to SC group was observed. TA group presented decrease in diastolic function in relation to other groups. The trained groups showed significant increases in cardiomyocytes diameter. SA and TA groups showed increase in collagen volumetric fraction in relation to SC and TC groups. CONCLUSION: The results show that AAS treatment associated to swimming training induces CH, mainly by the increase in interstitial collagen, which can lead to loss of diastolic function.

Anabolic steroid associated to physical training induces deleterious cardiac effects.

PURPOSE: Cardiac aldosterone might be involved in the deleterious effects of nandrolone decanoate (ND) on the heart. Therefore, we investigated the involvement of cardiac aldosterone, by the pharmacological block of AT1 or mineralocorticoid receptors, on cardiac hypertrophy and fibrosis. METHODS: Male Wistar rats were randomized into eight groups (n = 14 per group): Control (C), nandrolone decanoate (ND), trained (T), trained ND (TND), ND + losartan (ND + L), trained ND + losartan (TND + L), ND + spironolactone (ND + S), and trained ND + spironolactone (TND + S). ND (10 mg·kg(-1)·wk(-1)) was administered during 10 wk of swimming training (five times per week). Losartan (20 mg·kg(-1)·d(-1)) and spironolactone (10 mg·kg(-1)·d(-1)) were administered in drinking water. RESULTS: Cardiac hypertrophy was increased 10% by using ND and 17% by ND plus training (P < 0.05). In both groups, there was an increase in the collagen volumetric fraction (CVF) and cardiac collagen type III expression (P < 0.05). The ND treatment increased left ventricle-angiotensin-converting enzyme I activity, AT1 receptor expression, aldosterone synthase (CYP11B2), and 11-ß hydroxysteroid dehydrogenase 2 (11ß-HSD2) gene expression and inflammatory markers, TGFß and osteopontin. Both losartan and spironolactone inhibited the increase of CVF and collagen type III. In addition, both treatments inhibited the increase in left ventricle-angiotensin-converting enzyme I activity, CYP11B2, 11ß-HSD2, TGFß, and osteopontin induced by the ND treatment. CONCLUSIONS: We believe this is the first study to show the effects of ND on cardiac aldosterone. Our results suggest that these effects may be associated to TGFß and osteopontin. Thus, we conclude that the cardiac aldosterone has an important role on the deleterious effects on the heart induced by ND.

Cholinergic stimulation with pyridostigmine increases heart rate variability and baroreflex sensitivity in rats.

OBJECTIVE: Impaired parasympathetic modulation increases the risk for sudden death in patients with heart diseases. Therefore, cholinergic stimulation may have a potential protective role. The aim of this study was to verify the effects of pyridostigmine bromide, a reversible cholinesterase inhibitor, on heart rate (HR), blood pressure (BP), HR and BP variability, and baroreflex sensitivity (BS). METHODS: Male Wistar rats were divided in two groups: (1) treated with pyridostigmine in drinking water (7 days, n=10; PYR) and (2) a control group (n=12; CTR). BP was recorded in freely moving rats, and HR and BP variability were quantified by the standard deviation (S.D.) of the mean values during a 30-min period and by spectral analysis. BS was assessed by the ratio between pulse interval and BP power spectra (spontaneous BS) and also by the changes on HR produced by phenylephrine and sodium nitroprusside-induced BP changes. RESULTS: Treated rats had a PYR intake of 7.91+/-1.90 mg/day (approximately 31 mg/kg/day). There were no differences between groups concerning resting HR (P=0.158), systolic BP (P=0.481), and BP variability (P=0.201). On the other hand, treatment with PYR increased HR variability on the time domain (S.D.-PYR: 13.5+/-5.3 ms vs. CTR: 9.9+/-3.6 ms; P=0.034) and frequency domain (Total power--PYR: 208.3+/-157.7 ms(2) vs. CTR: 109.2+/-65.6 ms(2); P=0.030). BS was also augmented with PYR for both the spontaneous method (High frequency band--PYR: 2.55+/-1.06 ms/mm Hg vs. CTR: 1.85+/-0.60 ms/mm Hg; P=0.033) and the drug-induced reflex bradycardia (PYR: 2.48+/-1.02 bpm/mm Hg vs. CTR: 1.54+/-0.58 bpm/mm Hg; P=0.024) and reflex tachycardia (PYR: 4.08+/-1.04 bpm/mm Hg vs. CTR: 2.95+/-1.30 bpm/mm Hg; P=0.037). CONCLUSIONS: In conclusion, treatment with pyridostigmine increased HR variability and BS in normal rats with no modifications on basal hemodynamic parameters. Considering that reduced HR variability and baroreflex sensitivity are independent risk factors in heart disease, the present results support the concept that cholinergic stimulation with pyridostigmine may become a therapeutic option for vagal dysfunction.