The effects of flavonoids in experimental sepsis: A systematic review and meta-analysis.

Sepsis is a host's dysregulated immune response to an infection associated with systemic inflammation and excessive oxidative stress, which can cause multiple organ failure and death. The literature suggests that flavonoids, a broad class of secondary plant metabolites, have numerous biological activities which can be valuable in the treatment of sepsis. This study aimed to review the effects of flavonoids on experimental sepsis, focusing mainly on survival rate, and also summarizing information on its mechanisms of action. We searched in the main databases up to November 2022 using relevant keywords, and data were extracted and analyzed qualitatively and quantitatively. Thirty-two articles met the study criteria for review and 29 for meta-analysis. Overall, 30 different flavonoids were used in the studies. The flavonoids were able to strongly inhibit inflammatory response by reducing the levels of important pro-inflammatory mediators, for example, tumor necrosis factor-alpha and interleukin-1ß, oxidative stress, and showed antibacterial and anti-apoptotic actions. The meta-analysis found an increase of 50% in survival rate of the animals treated with flavonoids. They appear to act as multi-target drugs and may be an excellent therapeutic alternative to reduce a number of the complications caused by sepsis, and consequently, to improve survival rate.

d-Limonene Ameliorates Myocardial Infarction Injury by Reducing Reactive Oxygen Species and Cell Apoptosis in a Murine Model.

Myocardial infarction (MI) leads to high mortality, and pharmacological or percutaneous primary interventions do not significantly inhibit ischemia/reperfusion injuries, particularly those caused by oxidative stress. Recently, research groups have evaluated several naturally occurring antioxidant compounds for possible use as therapeutic alternatives to traditional treatments. Studies have demonstrated that d-limonene (DL), a monoterpene of citrus fruits, possesses antioxidant and cardiovascular properties. Thus, this work sought to elucidate the mechanisms of protection of DL in an isoproterenol-induced murine MI model. It was observed that DL (10 µmol) attenuated 40% of the ST elevation, reduced the infarct area, prevented histological alterations, abolished completely oxidative stress damage, restored superoxide dismutase activity, and suppressed pro-apoptotic enzymes. In conclusion, the present study demonstrated that DL produces cardioprotective effects from isoproterenol-induced myocardial infarction in Swiss mice through suppression of apoptosis.

H. pectinata (L.) Poit - Traditional uses, phytochemistry and biological-pharmacological activities in preclinical studies: A systematic review.

ETHNOPHARMACOLOGICAL RELEVANCE: H. pectinata (L.) Poit, popularly known as "sambacaitá" or "canudinho", is a plant endemic to north-eastern Brazil. Its aerial parts, leaves and flowers have traditionally been used to treat gastrointestinal disorders, rhinopharyngitis, nasal congestion, bacterial and fungal infections, fever, colic, inflammation, and pain. AIM OF THE STUDY: The aim of this review was to provide information on the botanical characteristics, ethnomedicinal uses, phytochemistry and biological-pharmacological activities of H. pectinata. MATERIALS AND METHODS: This systematic review followed the Cochrane Handbook Collaboration and the PRISMA guidelines. The review question was what are the biological-pharmacological activities of H. pectinata presented in non-clinical studies. The search for articles was conducted in the Medline (via PubMed), Embase, Web of Science, Scopus, Virtual Health Library, SciELO, Google Scholar and the Brazilian Digital Library of Theses and Dissertations databases. Two reviewers independently selected the studies that met the inclusion criteria, extracted the data, and assessed the risk of bias of the included studies. RESULTS: 39 articles were included in this review, of which 19 reported in vitro experiments, 16 in vivo studies and 4 in vivo and in vitro experiments. H. pectinata is a plant widely used in folk medicine in north-eastern Brazil for the treatment of various ailments, such as respiratory diseases, gastrointestinal disorders, bacterial and fungal infections, and general inflammation. Supporting its popular use, several in vitro and in vivo pharmacological investigations of the essential oil and extract of H. pectinata have demonstrated their anti-inflammatory, antinociceptive, antioxidant, antidepressant, anticancer, hepatoregenerative, healing, and antimicrobial activities. H. pectinata has been reported to contain 75 bioactive constituents, comprising 9 flavonoids, 54 terpenes, and 12 other compounds. CONCLUSION: H. pectinata is a plant commonly used in traditional medicine. Phytochemically, it contains several bioactive constituents, including terpenes and flavonoids, and has been shown to have antinociceptive, anti-inflammatory, antimicrobial and antitumour activity, as well as hepatorregenerative and healing effects, and low toxicity.

Educational Nursing Intervention in Reducing Hospital Readmission and the Mortality of Patients with Heart Failure: A Systematic Review and Meta-Analysis.

(1) Background: Heart failure (HF) represents a public health problem due to its high morbidity and mortality, increased consumption of health resources, prolonged hospitalization, and frequent readmissions. This study was conducted to evaluate the effectiveness of a nursing educational intervention using home visits (HV) combined with telephone contact in reducing hospital readmission and the mortality of patients with HF. (2) Methods: This is systematic review and meta-analysis of randomized controlled trials (RCTs). The databases used were CINAHL, Cochrane, PubMed and SciELO. A gray literature search included Google Scholar, OpenThesis, Clinical trials and reference lists of eligible studies. RCTs of patients diagnosed with HF were included, distributed between the control group (CG) and intervention (IG), in which the IG was submitted to the nursing intervention with HV and telephone contact in association and analyzed the result of readmission and mortality. (3) Results: The search resulted in 2528 articles and, after following steps, 11 remained for final analysis. A total of 1417 patients were analyzed and distributed: 683 in the IG and 734 in the CG. As a primary outcome, the meta-analysis identified a 36% reduction in the risk of readmission [RR 0.64, 95% CI, 0.54−0.75, p < 0.01] and a 35% reduction in mortality in the IG [RR 0.65, 95% CI, 0.50−0.85, p < 0.01]. Heterogeneity was moderate for readmission and homogeneous for mortality. (4) Conclusions: HV and telephone contact are an effective intervention strategy for nurses' educational practice.

Enhancement of the functionality of women with knee osteoarthritis by a gel formulation with Caryocar coriaceum Wittm ("Pequi") nanoencapsulated pulp fixed oil.

Osteoarthritis (OA) is a degenerative joint disease that occurs when there is a change in the mechanical and biological properties of the articular cartilage and the subchondral bone; The condition is more prevalent in women than in men. Pequi oil (PO), which is extracted from the fruits of the pequi tree (Caryocar coriaceum Wittm), is widely used in traditional medicine in the Brazilian northeast for the management of inflammation and joint pain. The aim of this study was to develop a pharmaceutical formulation containing Carbopol® hydrogel nanoencapsulated with pequi pulp fixed oil (PeONC) and evaluate its therapeutic effect on functionality and pain in women with knee osteoarthritis. The study was divided into two stages: Stage 1 - preparation and physico-chemical characterization of the pharmaceutical formulation containing PeONC, cell viability assays and skin irritability testing. Step 2 - A double-blind randomized clinical trial evaluating knee symptoms, quality of life, pressure pain, function, muscle strength and range of motion. The nanoformulation was in a gel form, with a particle size of 209.5 ± 1.06 nm, a pH of 6.23 ± 0.45, a zeta potential of - 23.1 ± 0.4 mV, a polydispersity index of 0.137 ± 0.52, and containing nanocapsules with a spherical shape a polymeric wall and an oily nucleus. The gel showed no cytotoxicity and was not irritating to human skin. The treatment with PeONC increased the strength of the knee flexor and extensor muscles and the total motion range of the knee. In addition, the treatment reduced knee instability, pain, swelling, and locking; There was also an improvement in some items of the SF-36 quality of life questionnaire such as in respect of functional capacity and social aspects. In conclusion, PeONC was found to be a stable, safe formulation with no toxicity in respect of topical use in humans. Additionally, the treatment produced an increase in muscle strength and functionality that was associated with reduced knee symptoms and improved quality of life. Our findings showed that in a group of women treated with PeONC mitigated the symptoms of knee osteoarthritis.

Insights into the actions of angiotensin-1 receptor (AT1R) inverse agonists: Perspectives and implications in COVID-19 treatment.

New coronavirus SARS-CoV-2 (COVID-19) has caused chaos in health care systems. Clinical manifestations of COVID-19 are variable, with a complex pathophysiology and as yet no specific treatment. It has been suggested that the renin-angiotensin-aldosterone system has a possible role in the severity of cases and the number of deaths. Our hypothesis is that drugs with inverse agonist effects to the angiotensin-1 receptor can be promising tools in the management of patients with COVID-19, possibly avoiding complications and the poor evolution in some cases. Any risk factors first need to be identified, and the most appropriate time to administer the drugs during the course of the infection also needs to be established. Several angiotensin receptor blockers (ARB) have a favorable profile and are important candidates for the treatment of COVID-19. In this review we discussed a set of compounds with favorable profile for COVID-19 treatment, including azilsartan, candesartan, eprosartan, EXP3174, olmesartan, telmisartan, and valsartan. They are effective as inverse agonists and could reduce the "cytokine storm" and reducing oxidative stress. As COVID-19 disease has several evolution patterns, the effectiveness of ARB therapy would be related to infection "timing", patient risk factors, previous use of ARBs, and the specific molecular effects of an ARB. However, controlled studies are needed to identify whether ARBs are beneficial in the treatment of patients with COVID-19.

Resistance training improves cardiac function and cardiovascular autonomic control in doxorubicin-induced cardiotoxicity.

Doxorubicin (DOX) is an anticancer chemotherapy drug that is widely used in clinical practice. It is well documented that DOX impairs baroreflex responsiveness and left ventricular function and enhances sympathetic activity, cardiac sympathetic afferent reflexes and oxidative stress, which contribute to hemodynamic deterioration. Because resistance training (RT)-induced cardioprotection has been observed in other animal models, the objective of this study was to assess the effects of RT during DOX treatment on hemodynamics, arterial baroreflex, cardiac autonomic tone, left ventricular function and oxidative stress in rats with DOX-induced cardiotoxicity. Male Wistar rats were submitted to a RT protocol (3 sets of 10 repetitions, 40% of one-repetition maximum (1RM) of intensity, 3 times per week, for 8 weeks). The rats were separated into 3 groups: sedentary control, DOX sedentary (2.5 mg/kg of DOX intraperitoneal injection, once a week, for 6 weeks) and DOX + RT. After training or time control, the animals were anesthetized and 2 catheters were implanted for hemodynamic, arterial baroreflex and cardiac autonomic tone. Another group of animals was used to evaluate left ventricular function. We found that RT in DOX-treated rats decreased diastolic arterial pressure, heart rate, sympathetic tone and oxidative stress. In addition, RT increased arterial baroreflex sensitivity, vagal tone and left ventricular developed pressure in rats with DOX-induced cardiotoxicity. In summary, RT is a useful non-pharmacological strategy to attenuate DOX-induced cardiotoxicity.

Nephrotoxic Effects Caused by Occupational Exposure to Agrochemicals in a Region of Northeastern Brazil: A Cross-Sectional Study.

The objective of the present study was to evaluate the renal function of rural workers in a city of northeastern Brazil. A cross-sectional study was carried out with 208 workers in Boquim, Sergipe, Brazil. Renal function markers and butyrylcholinesterase (BChE) were evaluated and the glomerular filtration rate (GFR) was determined. The sample consisted mainly of illiterate males with a low usage of personal protective equipment and no training. Approximately 40% had some level of renal failure. Relative risk (1.59) of GFR alteration was higher in workers with more than 5 yr of exposure, mainly to organophosphates. Workers more than 60 yr of age presented a 17.06 greater risk for manifesting acute intoxication. Butyrylcholinesterase reduction was associated with reports of intoxication (relative risk of 11.36). We concluded that exposure to pesticides represented a risk factor for the development of nephrotoxic effects and alteration of renal function, which reinforced the need to implement measures to protect rural workers. Environ Toxicol Chem 2021;40:1132-1138. © 2020 SETAC.

NOX-dependent reactive oxygen species production underlies arrhythmias susceptibility in dexamethasone-treated rats.

Dexamethasone is the most clinically used glucocorticoid with an established role in the treatment of a wide spectrum of inflammatory-related diseases. While the therapeutic actions are well known, dexamethasone treatment causes a number of cardiovascular side effects, which are complex, frequent and, in some cases, clinically unnoticeable. Here, we investigated whether a therapeutic regimen of dexamethasone affects cardiac arrhythmogenesis, focusing on the contribution of Nox-derived reactive oxygen species (ROS). Male Wistar rats were treated with dexamethasone (2 mg/kg, i.p.) for 7 days. Afterward, hemodynamic measurements, autonomic modulation, left ventricular function, cardiac fibrosis, reactive oxygen species (ROS) generation, Nox protein expression, superoxide dismutase (SOD) and catalase activities, and arrhythmias incidence were evaluated. Here, we show that dexamethasone increases blood pressure, associated with enhanced cardiac and vascular sympathetic modulation. Moreover, a marked increase in the cardiac ROS generation was observed, whereas the enhanced SOD activity did not prevent the higher levels of lipid peroxidation in the dexamethasone group. On the other hand, increased cardiac Nox 4 expression and hydrogen peroxide decomposition rate was observed in dexamethasone-treated rats, while Nox 2 remained unchanged. Interestingly, although preserved ventricular contractility and ß-adrenergic responsiveness, we found that dexamethasone-treated rats displayed greater interstitial and perivascular fibrosis than control. Surprisingly, despite the absence of arrhythmias at basal condition, we demonstrated, by in vivo and ex vivo approaches, that dexamethasone-treated rats are more susceptible to develop harmful forms of ventricular arrhythmias when challenged with pharmacological drugs or burst pacing-induced arrhythmias. Notably, concomitant treatment with apocynin, an inhibitor of NADPH oxidase, prevented these ectopic ventricular events. Together, our results reveal that hearts become arrhythmogenic during dexamethasone treatment, uncovering the pivotal role of ROS-generating NADPH oxidases for arrhythmias vulnerability.

Resistance training improves cardiovascular autonomic control and biochemical profile of rats exposed to Western diet in the perinatal period. / Treinamento resistido melhora controle autonômico cardiovascular e perfil bioquímico de ratos expostos a dieta ocidental no período perinatal.

INTRODUCTION AND OBJECTIVES: Consumption of a Western diet during the perinatal period is associated with development of cardiovascular disease. Resistance training (RT) has been used to treat cardiovascular disorders. The aim of this work was to assess the effect of RT on cardiometabolic disorders in rats exposed to a Western diet in the perinatal period. METHODS: Female Wistar rats were fed with control or Western diet during pregnancy and lactation. The pups were divided into three groups: Control (C), Western Diet Sedentary (WDS) and Western Diet + RT (WDRT). At 60 days of age, all animals started the RT protocol (five times a week for four weeks). At the end, blood pressure was recorded for analysis of heart rate variability and baroreflex sensitivity (BRS). Blood samples were collected for biochemical analysis. RESULTS: RT reduced blood pressure and vascular sympathetic modulation and increased BRS. There were improvements in biochemical profile, with reductions in fasting blood glucose, total cholesterol and low-density lipoprotein, and an increase in high-density lipoprotein. CONCLUSION: RT led to beneficial adaptations in the cardiovascular system, mediated by changes in the mechanisms of autonomic control and biochemical profile of animals exposed to a Western diet in the perinatal period.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats.

BACKGROUND: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. OBJECTIVES: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. METHODS: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). RESULTS: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). CONCLUSIONS: DL produces bradycardia and antiarrhythmic activity in rat heart.

Resistance exercise restores endothelial function and reduces blood pressure in type 1 diabetic rats.

BACKGROUND: Resistance exercise effects on cardiovascular parameters are not consistent. OBJECTIVES: The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats. METHODS: Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings. RESULTS: A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group. CONCLUSIONS: Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats / Efeitos Bradicárdicos e Antiarrítmicos do D-Limoneno em Ratos

Abstract Background: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. Objectives: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. Methods: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). Results: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). Conclusions: DL produces bradycardia and antiarrhythmic activity in rat heart.

Resumo Fundamento: O D-limoneno (DL) é um monoterpeno e o principal componente do óleo essencial de frutas cítricas. Ele apresenta atividades anti-hiperglicêmicas e vasodilatadoras. Objetivos: Este estudo avaliou os efeitos cardiovasculares e antiarrítmicos potenciais do DL em ratos. Métodos: Os parâmetros hemodinâmicos e eletrocardiográficos (ECG) foram mensurados em ratos Wistar machos que, sob anestesia, tiveram a aorta abdominal e a veia cava inferior canuladas e receberam eletrodos implantados subcutaneamente. Na abordagem in vitro, o coração foi removido e perfundido utilizando a técnica de Langendorff. O nível de significância adotado foi de 5% (p < 0,05). Resultados: DL, nas doses de 10, 20 e 40 mg/kg (i.v), produziu bradicardia intensa e persistente associada à hipotensão. A bradicardia com QTc prolongado foi observada no registro in vivo do ECG. No modelo in vivo de arritmia induzida por Bay K8644, DL (10 mg / kg) houve diminuição do escore da arritmia de 15,33 ± 3,52 para 4,0 ± 2,64 u.a (p < 0,05, n = 4). Em corações perfundidos isolados, o DL (10-3 M) promoveu reduções significativas na frequência cardíaca (de 228,6 ± 8,5 ms para 196,0 ± 9,3 bpm; p < 0,05) e na pressão desenvolvida do ventrículo esquerdo (de 25,2 ± 3,4 para 5,9 ± 1,8 mmHg; n = 5, p < 0,05). Conclusões: O DL produz bradicardia e atividade antiarrítmica no coração de ratos.

Induction of chronic non-inflammatory widespread pain increases cardiac sympathetic modulation in rats.

Fibromyalgia (FM) is characterized by chronic non-inflammatory widespread pain (CWP) and changes in sympathetic function. In attempt to elucidate the pathophysiological mechanisms of FM we used a well-established CWP animal model. We aimed to evaluate changes in cardiac autonomic balance and baroreflex function in response to CWP induction in rats. CWP was induced by two injections of acidic saline (pH 4.0, n=8) five days apart into the left gastrocnemius muscle. Control animals were injected twice with normal saline (pH 7.2, n=6). One day after the second injection of acidic saline or normal saline, the animals had pulse interval (PI) and systolic arterial pressure (SAP) variability, and spontaneous baroreflex sensitivity (BRS) evaluated. After induction of CWP, there was an increase of power in the low frequency (LF) band of PI spectrum (12.75 ± 1.04 nu), a decrease in the high frequency (HF) band (87.25 ± 1.04 nu) and an increase of LF/HF ratio (0.16 ± 0.01), when compared to control animals (7.83 ± 1.13 nu LF; 92.16 ± 1.13 nu HF; 0.08 ± 0.01 LF/HF). In addition, there was an increase of power in the LF band of SAP spectrum (7.93 ± 1.39 mmHg(2)) when compared to control animals (2.97 ± 0.61 mmHg(2)). BRS was lower in acidic saline injected rats (0.59 ± 0.06 ms/mmHg) when compared to control animals (0.71 ± 0.03 ms/mmHg). Our results showed that induction of CWP in rats shifts cardiac sympathovagal balance towards sympathetic predominance and decreases BRS. These data corroborate findings in humans with FM.

Effects of transcutaneous electrical diaphragmatic stimulation on the cardiac autonomic balance in healthy individuals: a randomized clinical trial / Efeitos da estimulação diafragmática elétrica transcutânea sobre o balanço autonômico cardíaco de indivíduos hígidos: ensaio clínico randomizado / Los efectos de la estimulación eléctrica transcutánea del diafragma en el balance autónomo cardiaco en individuos sanos: estudio clínico aleatorio

ABSTRACT The transcutaneous electrical diaphragmatic stimulation (TEDS) is a technique of respiratory muscle activation that affects breathing pattern and rhythm. In an attempt to evaluate changes in cardiac autonomic balance in response to TEDS in healthy individuals, we used a well-established TEDS model. Twenty-two volunteers aged between 22 and 35 years old, with no cardiac pathology history, were randomized into two groups (control, n = 8; TEDS, n = 14). The individuals were allowed to rest in supine position and were then subjected to the electrical stimulation protocol. The control group was subjected to electrical stimulation at perceptive level, whereas for the TEDS group the electric stimulus generated diaphragm contraction. Cardiac intervals (CI) were sampled by a Polar RS800CX monitor. Cardiac interval variability was studied in the time and frequency domains. In the control group, electrical stimulation did not change cardiac interval length and variability (CI: 761±44 vs. 807±39 ms; RMSSD: 37±9 vs. 42±13 ms ; LF: 69±6 vs. 67±5 nu; HF: 31±6 vs. 33±5 nu; all comparisons versus baseline). Nevertheless, as compared to baseline, TEDS group showed decreased sympathetic cardiac modulation (LF: 43±3 vs. 63±4 nu) and increased parasympathetic cardiac modulation (RMSSD: 109±10 vs. 41±6 ms; HF: 57±3 vs. 37±4 nu) during diaphragmatic stimulation. However, cardiac interval length was not changed by electrical stimulation (CI: 686±59 vs. 780±31 ms). It can be suggested that the use of TEDS stimulus leads to pronounced changes in the cardiac sympathovagal balance, with higher parasympathetic cardiac modulation, possibly induced by increased diaphragmatic excursion.

RESUMO A estimulação diafragmática elétrica transcutânea (EDET) é uma técnica de mobilização da musculatura respiratória que interfere no padrão e no ritmo respiratório. Na tentativa de avaliar as alterações no balanço autonômico cardíaco à EDET em indivíduos saudáveis, foi utilizado um modelo já estabelecido de eletroestimulação diafragmática. 22 voluntários com idades entre 22 e 35 anos, sem histórico cardíaco, foram randomizados em dois grupos (controle, n=8; EDET, n=14). O protocolo de eletroestimulação foi aplicado nos indivíduos em repouso (posição supina). O grupo controle foi submetido a estimulação elétrica em nível perceptivo, enquanto no grupo EDET o estímulo gerava contração diafragmática. Os intervalos cardíacos (CI) foram registrados por cardiofrequencímetro Polar (RS800CX). A variabilidade do intervalo cardíaco foi estudada nos domínios de tempo e frequência. No grupo controle, a estimulação elétrica não alterou a duração do intervalo cardíaco e sua variabilidade (CI: 761±44 vs. 807±39ms; RMSSD: 37±9 vs. 42±13ms; LF: 69±6 vs. 67±5nu; HF: 31±6 vs. 33±5nu), em comparação às condições basais). No entanto, o grupo EDET apresentou diminuição na modulação simpática cardíaca (LF: 43 ±3 vs. 63±4nu) e aumento da modulação parassimpática cardíaca (RMSSD: 109±10 vs. 41±6ms; HF: 57±3 vs. 37±4nu) durante a eletroestimulação diafragmática. No entanto, a duração do intervalo cardíaco não foi alterada por estimulação elétrica (CI: 686±59 vs. 780±31ms). Pode-se sugerir que o uso da EDET promove mudanças acentuadas no balanço simpatovagal, resultando em maior modulação parassimpática cardíaca, possivelmente induzida pelo aumento da mobilidade diafragmática.

RESUMEN La estimulación eléctrica transcutánea del diafragma (EETD) es un método que moviliza la musculatura respiratoria que interfiere en el patrón y en la frecuencia respiratoria. Para evaluar las alteraciones en el balance autónomo cardiaco por la EETD en individuos sanos, se empleó un modelo prestablecido de estimulación eléctrica muscular del diagrama. Han participado 22 voluntarios con edad entre 22 y 35 años, sin enfermedades cardiacas, puestos en grupos aleatorios: Grupo control (n=8) y EETD (n=14). Se aplicó el protocolo de estimulación eléctrica en individuos en posición decúbito supino. Al grupo control se lo sometió a la estimulación eléctrica a nivel perceptual, mientras que en el EETD la estimulación le generaba contracción del diafragma. Los intervalos cardiacos (CI) se registraron a través del monitor de ritmo cardiaco polar (RS800CX). Se estudió la variabilidad del intervalo cardiaco en los dominios tiempo y frecuencia. En el grupo control, la estimulación eléctrica no presentó alteraciones en la duración del intervalo cardiaco y su variabilidad (CI: 761±44 vs. 807±39ms; RMSSD: 37±9 vs. 42±13ms; LF: 69±6 vs. 67±5nu; HF: 31±6 vs. 33±5nu; comparado con las condiciones de base). Pero si comparado las condiciones de base en el grupo EETD presentó una disminución en la modulación simpática cardiaca (LF: 43±3 vs. 63±4nu) y un aumento en la modulación parasimpática cardiaca (RMSSD: 109±10 vs. 41±6ms; HF: 57±3 vs. 37±4nu) durante la realización de este método. Sin embargo, la duración del intervalo cardiaco no presentó alteraciones por la estimulación eléctrica del diafragma (CI: 686±59 vs. 780±31ms). Se puede concluir que el empleo de la EETD promueve cambios significativos en el balance simpático, resultando en una modulación parasimpática cardiaca más grande, posiblemente inducida del aumento de la movilidad del diafragma.

Resistance Exercise Restores Endothelial Function and Reduces Blood Pressure in Type 1 Diabetic Rats / Exercício Resistido Restaura a Função Endotelial e Reduz a Pressão Arterial de Ratos Diabéticos Tipo 1

Background: Resistance exercise effects on cardiovascular parameters are not consistent. Objectives: The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats. Methods: Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings. Results: A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group. Conclusions: Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats. .

Fundamento: Os efeitos do exercício resistido sobre os parâmetros cardiovasculares não são consistentes. Objetivos: Foram avaliados os efeitos do exercício resistido sobre as alterações na glicemia, reatividade vascular e pressão arterial de ratos diabéticos. Métodos: Ratos Wistar foram divididos em três grupos: grupo controle (n = 8), diabético sedentário (n = 8) e diabético treinado (n = 8). O exercício resistido foi realizado no aparelho de agachamento para ratos e consistiu em três séries de dez repetições com uma intensidade de 50%, três vezes por semana, durante 8 semanas. As alterações na reatividade vascular foram avaliadas em anéis de artéria mesentérica superior. Resultados: Foi observada uma redução significativa da resposta máxima dos relaxamentos induzidos por acetilcolina no grupo diabético sedentário (78,1% ± 2) e um aumento do grupo diabético treinado (95 ± 3%), sem alterar a potência. Na presença de NG-nitro-L-arginina metil éster, os relaxamentos induzidos por acetilcolina foram significativamente reduzidos nos grupos controle e diabético treinado, mas não no grupo diabético sedentário. Além disso, foi observado um aumento significativo (p < 0,05) da pressão arterial média no grupo diabético sedentário de 104,9 ± 5 para 126,7 ± 5 mmHg, quando comparado ao grupo controle. Por outro lado, o grupo diabético treinado apresentou redução significativa (p < 0,05) nos níveis da pressão arterial média de 126,7 ± 5 mmHg para 105,1 ± 4 mmHg, quando comparado ao diabético sedentário. Conclusões: O exercício resistido foi capaz de restaurar a funcionalidade endotelial e impedir o aumento da pressão arterial em ratos com ...

Treinamento aeróbio previne alterações na vasodilatação dependente do endotélio em ratos diabéticos / Aerobic training prevents changes in endothelium-dependent vasodilation of diabetic rats

O objetivo do presente estudo é verificar os efeitos do treinamento aeróbio sobre a reatividade vascular em artéria mesentérica de ratos diabéticos. Ratos Wistar foram divididos em três grupos: controle sedentário (CS), diabético sedentário (DS) e diabético treinado (DT). Alterações na reatividade vascular foram avaliadas após a última sessão de treinamento, por meio da obtenção de curvas concentração-resposta. Os testes t de Student ou análise de variância (ANOVA) de duas-vias, seguida do pós-teste de Bonferroni, foram realizados para avaliar a significância das diferenças entre as médias. Foi observada uma redução dos relaxamentos induzidos por acetilcolina no grupo DS (79,7 ± 3,0 %), quando comparado ao CS (98,8 ± 3,0) e uma manutenção dos valores normais no grupo DT (100,1 ± 5,3 %). Os resultados sugerem que o treinamento aeróbio é capaz de proporcionar efeitos benéficos na função vascular de ratos diabéticos.

The aim of this study was to investigate the effects of aerobic training on the vascular reactivity in the mesenteric artery from diabetic rats. Wistar rats were divided into three groups: sedentary control (SC), sedentary diabetic (SD) and trained diabetic (TD). Changes in vascular reactivity were assessed after the last training session by obtaining concentration-response curves. Student's t-test or two-way analysis of variance (ANOVA) followed by the Bonferroni post-test were performed to evaluate the significance of differences between means. A reduction was observed in the relaxation induced by acetylcholine in the SD group (79.7 ± 3.0%) compared to SC (98.8 ± 3.0%), and maintenance of normal values ​​in the TD group (100.1 ± 5.3%). The results suggest that exercise training can have beneficial effects on vascular function in diabetic rats.