Efeito da sinvastatina e do propranolol no desenvolvimento da lesão periapical de ratos submetidos ao estresse / Effect of Simvastatin and Propranolol on the development of periapical lesions in rats subjected to stress

Uma vez que o estresse crônico pode estimular o sistema nervoso simpático, diminuindo a resposta imune, favorecendo a perda óssea frente a um processo inflamatório, os objetivos deste estudo foram: 1) Avaliar os efeitos de modelos de indução de estresse no desenvolvimento da periodontite apical (P.a) e avaliar o nível de estresse gerado pelos mesmos; 2) A partir do melhor protocolo de estresse obtido foi avaliado o perfil inflamatório da PA induzida em animais sob condições de estresse, utilizando sistemicamente a Sinvastatina, Propranolol e a Sinvastatina associada ao propranolol. Na primeira parte foram utilizados 32 ratos Wistar (N=8) divididos aleatoriamente em: SE: sem estresse, sem periodontite apical (P.a); SE+P.a: sem estresse, com P.A; EP+P.a: Estresse previsível + P.a; EI+P.a: estresse imprevisível + P.a. Os animais foram submetidos ao estresse crônico por 42 dias sendo que no dia 21 foi induzida a P.a. Para comprovação do estresse foram utilizadas análises de peso e comportamentais de campo aberto (CA) e labirinto em y (Y). Foram realizadas análises micro tomográfica e histológica para avaliar o efeito de ambas as metodologias sobre a progressão da P.a. Os dados foram avaliados estatisticamente. Observou-se que não houve diferença no ganho de peso entre os animais SE e SE+P.a. Em relação aos grupos estressados o grupo estresse imprevisível apresentou menor ganho de peso quando comparado ao grupo sem estresse. Nos testes comportamentais, Y e CA observou-se um mesmo padrão de comportamento nos animais do grupo SE e SE+P.a (p>0.05). Verificou-se diferenças entre os grupos SE+P.a e EI +P.a no volume da lesão periapical, mas não houve diferença entre os protocolos de estresse. A Análise histológica mostrou maior área de P.a nos animais do grupo EI+P.a o que também foi observado pela análise microtomográfica. Na segunda etapa foram utilizados 48 animais divididos em 5 grupos (N=8): SE+P.a: sem estresse e com P.a; E+SS: Estresse + Periodontite Apical + soro; E+SN: Estresse + Periodontite Apical + Sinvastatina; E+P: Estresse + Periodontite Apical + Propranolol e S+SN+P: Estresse + Periodontite Apical + Sinvastatina + Propranolol. O protocolo de estresse utilizado foi o estresse crônico imprevisível por 42 dias. Realizou-se análises de peso e comportamentais de labirinto em y e campo aberto. Após a eutanásia foram realizadas as análises microtomográfica e a análise histológica e histomorfométrica. Os valores obtidos foram analisados estatisticamente.Observouse que todos os grupos medicados apresentaram ganho de peso maior do que o grupo solução salina. No grupo Sinvastatina e no grupo Propranolol, os animais apresentaram maior atividade locomotora do que no grupo Solução salina. O volume da P.a foi significativamente menor nos grupos Sinvastatina e Propranolol quando comparado ao grupo solução salina. Na análise histológica observou-se que a área da lesão foi significativamente menor nos animais do grupo Sinvastatina quando comparado ao da solução salina, bem como menor intensidade e extensão do infiltrado inflamatório. Concluindo-se que o estresse crônico imprevisível aumenta a perda óssea periapical em animais com PA induzida. Além disso, concluiu-se que tanto a Sinvastatina quanto o Propranolol reduze o estresse crônico, reduzindo a perda óssea nestes animias (AU)

Since chronic stress can stimulate the sympathetic nervous system, decreasing the immune response, favoring bone loss in the face of an inflammatory process, the objectives of this study were: 1) To evaluate the effects of stress induction models on the development of apical periodontitis (P.a) and assess the level of stress generated by them; 2) Based on the best stress protocol obtained, the inflammatory profile of BP induced in animals under stress conditions was evaluated, systemically using Simvastatin, Propranolol and Simvastatin associated with propranolol. In the first part, 32 Wistar rats (N=8) were randomly divided into: SE: without stress, without apical periodontitis (P.a); SE+P.a: without stress, with P.A; EP+P.a: Predictable stress + P.a; EI+P.a: unpredictable stress + P.a. The animals were subjected to chronic stress for 42 days, and on the 21st, P.a. To prove the stress, weight and behavioral analyzes of open field (CA) and maze in y (Y) were used. Micro tomographic and histological analyzes were performed to evaluate the effect of both methodologies on the progression of P.a. Data were statistically evaluated. It was observed that there was no difference in weight gain between SE and SE+P.a animals. In relation to the stressed groups, the unpredictable stress group showed less weight gain when compared to the non-stress group. In the behavioral tests, Y and CA, the same pattern of behavior was observed in animals from the SE and SE+P.a groups (p>0.05). There were differences between groups SE+P.a and EI +P.a in the volume of the periapical lesion, but there was no difference between the stress protocols. The histological analysis showed a greater area of P.a in the animals from the EI+P.a group, which was also observed by the microtomographic analysis. In the second stage, 48 animals were divided into 5 groups (N=8): SE+P.a: without stress and with P.a; E+SS: Stress + Apical Periodontitis + serum; E+SN: Stress + Apical Periodontitis + Simvastatin; E+P: Stress + Apical Periodontitis + Propranolol and S+SN+P: Stress + Apical Periodontitis + Simvastatin + Propranolol. The stress protocol used was unpredictable chronic stress for 42 days. Weight and behavioral analyzes of y-maze and open field were performed. After euthanasia, microtomographic analysis and histological and histomorphometric analysis were performed. The values obtained were statistically analyzed. It was observed that all medicated groups had greater weight gain than the saline group. In the Simvastatin group and in the Propranolol group, the animals showed greater locomotor activity than in the Saline group. The BP volume was significantly lower in the Simvastatin and Propranolol groups when compared to the saline group. In the histological analysis, it was observed that the area of the lesion was significantly smaller in the animals of the Simvastatin group when compared to the saline solution, as well as lower intensity and extension of the inflammatory infiltrate. Concluding that unpredictable chronic stress increases periapical bone loss in animals with induced AP. In addition, it was concluded that both Simvastatin and Propranolol reduce chronic stress, reducing bone loss in these animals. (AU)

Paroxysmal Sympathetic Hyperactivity in Patients Victims of Traumatic Brain Injury: Literature Review

The present literature review aims to present the physiology of paroxysmal sympathetic hyperactivity (PSH) as well as its clinical course, conceptualizing them, and establishing its diagnosis and treatment. Paroxysmal sympathetic hyperactivity is a rare syndrome, which often presents after an acute traumatic brain injury. Characterized by a hyperactivity of the sympathetic nervous system, when diagnosed in its pure form, its symptomatologic presentation is through tachycardia, tachypnea, hyperthermia, hypertension, dystonia, and sialorrhea. The treatment of PSH is basically pharmacological, using central nervous system suppressors; however, the nonmedication approach is closely associated with a reduction in external stimuli, such as visual and auditory stimuli. Mismanagement can lead to the development of serious cardiovascular and diencephalic complications, and the need for neurosurgeons and neurointensivists to know about PSH is evident in order to provide a fast and accurate treatment of this syndrome.

Estratificação de Risco e Avaliação da Atividade Simpática Cardíaca Utilizando Imagem Miocárdica com [123I] MIBG na Denervação Renal / Risk Stratification and Cardiac Sympathetic Activity Assessment Using Myocardial [123I] MIBG Imaging in Renal Denervation

Resumo A hiperativação do sistema nervoso simpático desempenha um papel central na fisiopatologia da hipertensão. O objetivo deste estudo foi avaliar a atividade simpática cardíaca e investigar o papel da cintigrafia miocárdica com metaiodobenzilguanidina com 123I ([123I] MIBG) na estratificação de risco cardiovascular de pacientes com hipertensão resistente tratados com denervação renal (DR). Dezoito pacientes foram incluídos neste estudo prospectivo (média de idade de 56 ± 10 anos, 27,8% mulheres). Ecocardiograma transtorácico, análise geral do sangue e cintilografia miocárdica com [(123I) MIBG] foram realizados antes e seis meses após a DR. Um paciente era considerado respondedor (R) se uma diminuição ≥ 5 mmHg na pressão arterial sistólica (PAS) média ambulatorial fosse observada no seguimento de seis meses. 66,7% dos pacientes foram R (diminuição na PAS de 20,6 ± 14,5 mmHg, vs. menos 8 ± 11,6 mmHg em não-respondedores (NR), p = 0,001). A relação coração-mediastino (RCM) inicial foi significativamente menor na linha basal no grupo R (1,6 ± 0,1 vs. 1,72 ± 0,1, p <0,02), mas semelhante em seis meses. Considerando os dois momentos no tempo, o grupo R teve valores iniciais de RCM mais baixos do que o grupo NR (p <0,05). Tanto o RCM tardio quanto a taxa de washout foram idênticos e nenhuma correlação significativa entre a resposta à DR ou qualquer índice de imagem com MIBG foi encontrada. A denervação renal efetivamente reduziu a pressão arterial na maioria dos pacientes, mas a imagem com [123I] MIBG não foi útil na previsão da resposta. Entretanto, houve evidência de overdrive do sistema nervoso simpático e, tanto a RCM inicial quanto tardia estavam reduzidas em geral, provavelmente colocando essa população em um risco maior de eventos adversos.

Abstract Hyperactivation of the sympathetic nervous system plays a central role in the pathophysiology of hypertension. The aim of this study was to assess cardiac sympathetic activity and investigate the role of myocardial123I-labelled meta-iodo benzyl guanidine ([123I] MIBG) scintigraphy in cardiovascular risk stratification of patients with resistant hypertension treated with renal denervation (RDN). Eighteen patients were included in this prospective study (mean age 56 ± 10 years old, 27.8% females). Transthoracic echocardiogram, general blood analysis and myocardial ([123I] MIBG scintigraphy were performed before and six-months after RDN. A patient was considered a responder (R) if a drop ≥ 5mmHg on mean systolic ambulatory blood pressure (BP) monitoring was observed at the six-month follow-up. 66.7% of patients were R (drop in systolic BP of 20.6 ± 14.5mmHg, vs minus 8 ± 11.6mmHg in non-responders (NR), p=0.001). Early heart-mediastinum ratio (HMR) was significantly lower at baseline in the R group (1.6 ± 0.1 vs 1.72 ± 0.1, p<0.02) but similar at six months. Considering both instants in time, the R group had lower early HMR values than the NR group (p<0.05). Both the late HMR and the washout rate were identical and no significant correlation between response to RDN or any MIBG imaging index was found. Renal denervation effectively lowered blood pressure in the majority of patients but [123I] MIBG was not useful in predicting the response. However, there was evidence of sympathetic overdrive and, both early and late HMR were overall reduced, probably putting this population at a higher risk of adverse events.

Estresse e periodontite: avaliação da inervação simpática no periodonto e da resposta adrenérgica após infecção por Porphyromonas gingivalis / Stress and periodontitis: evaluation of sympathetic innervation in the periodontium and the influence of adrenergic signaling on Porphyromonas gingivalis infection

O estresse agrava a doença periodontal por vários mecanismos, sendo a estimulação do sistema nervoso simpático (SNS) um deles. A literatura mostra que a estimulação de receptores ß-adrenérgicos (ß-AR) aumenta a angiogênese em ossos longos, e a expansão microvascular agrava a periodontite. Ainda, catecolaminas aumentam a virulência de periodontopatógenos e agem na resposta imune. Assim, o objetivo deste trabalho foi avaliar: (1) a inervação simpática no periodonto e a influência da ativação do SNS na vascularização periodontal em camundongos e (2) a influência do sistema adrenérgico nos fatores de virulência de Porphyromonas gingivalis (Pg) e na resposta imunológica a este patógeno in vivo (Galleria mellonella). Na primeira parte, camundongos receberam injeção intraperitoneal de solução salina (PBS) ou isoproterenol (ISO; agonista não seletivo ß adrenérgico) por 1 mês, para detecção in situ de tirosina hidroxilase, neuropeptídeo Y, transportador de norepinefrina (NET) e endomucina em mandíbulas. Expressão de mRNA de Vegf-a, Il-1ß, Il-6, Adrb2 e Rankl foi quantificada 2 h após administração de ISO/PBS em mandíbula e tíbias, que serviram como controle positivo. Diferentemente das tíbias, não houve alteração na expressão dos genes analisados em mandíbula. Por outro lado, NET foi mais expresso no osso alveolar do que na tíbia, sendo detectado nos osteoblastos, osteócitos e células do ligamento. Embora o padrão de inervação e a expressão de Adrb2 sejam semelhantes entre mandíbula e tíbia, o tratamento com ISO não influenciou no número e área de vasos positivos para endomucina. Na segunda parte, investigamos a influência adrenérgica na resposta imune de G. mellonella durante infecção por Pg utilizando norepinefrina (NE; agonista α e ß adrenérgico) e ISO. Pg também foi cultivada na presença de ISO (PgISO) ou NE para avaliação da ação direta dos compostos na bactéria. ISO sistêmico protegeu as larvas da infecção por Pg, aumentando o número de hemócitos e reduzindo a contagem de células de Pg na hemolinfa, exclusivamente pelo ß-AR. Diferentemente, NE aumentou mortalidade, diminuiu o número de hemócitos. Apenas PgISO aumentou a morte das larvas, apesar de ambos, NE e ISO, terem aumentado a expressão de fatores de virulência na bactéria in vitro. ISO circulante, concomitante com PgISO, reduziu parcialmente a mortalidade das larvas. A influência do estresse na doença periodontal envolve diversas vias que alteram os dois pilares da periodontite (microbiota e sistema imune). No entanto, a ação na resposta do hospedeiro parece ser superior, uma vez que a estimulação ß-AR em osso alveolar saudável não alterou a produção de citocinas pró-inflamatórias ou microvascularização e a modulação da resposta imune em G. mellonella por compostos adrenérgicos foi mais importante para o desfecho da infecção que sua ação direta sobre a bactéria.

Stress aggravates periodontitis, and one possible mechanism is the activation of sympathetic nervous system (SNS). The literature shows that stimulation of ß-adrenergic receptors (ß-AR) induces angiogenesis in long bones, and microvasculature amplification was linked to periodontitis severity. Moreover, catecholamines increase the virulence of some periodontopathogenic bacteria in vitro and influences the innate immunity. Thus, the aim of this study was (1) evaluate the presence and influence of the SNS in the stimulation of periodontal vasculature, and (2) the influence of the adrenergic system on Porphyromonas gingivalis (Pg) virulence and on the immunological response to this pathogen in vivo (Galleria mellonella larvae). For the first part, mice received isoproterenol (ISO, a non-selective ß-AR agonist) or saline (PBS) for 1 month, for in situ analysis of tyrosine hydroxylase, neuropeptide Y, norepinephrine transporter (NET) and endomucin in the mandibles. Vegfa, Il-1ß, Il-6, Adrb2 and Rankl mRNA expression was assessed 2 hours after PBS/ISO treatment for mandibles and tibia, that served as positive control. We observed that, differently from the tibia, the expression of these genes did not alter on the mandible. However, NET expression was detected in osteoblasts, osteocytes, and periodontal ligament fibroblasts, and were higher expressed when compared to the tibias from the same animals. Although the pattern of sympathetic innervation and Adrb2 expression were similar between tissues, ISO treatment did not increase the area or number of endomucin+ vessels. For the second part, we addressed the adrenergic signaling influence on G. mellonella immune system during Pg infection using norepinephrine (NE, α- and ß-AR agonist), ISO and octopamine (insect's endogenous hormone). Pg was also cultivated in the presence of ISO (PgISO) or NE to investigate the direct action of the ligands on bacterial virulence. Systemic administration of ISO protected the larvae from Pg infection by increasing hemocyte density accompanied by reduction of Pg load in hemolymph, in a ß-AR manner. In contrast, NE increased mortality, with decreased hemocyte count and no influence on the other parameters. Only PgISO increased larvae death, despite of ISO and NE increased virulence in vitro. The concomitant injection of systemic ISO partially reversed the toxicity of the PgISO. The influence of stress on periodontitis involves different pathways, that alter the two pillars of disease's pathogenesis (microbiota and immune system). However, the influence on the host's inflammatory response seems to overcome the other players, since ß-AR activation on healthy alveolar bone didn't alter cytokines production or microvasculature. Besides, the modulation of innate immunity by adrenergic signaling in G. mellonella was more important for the disease's outcome than it's direct action on the bacteria.

Referred Somatic Hyperalgesia Mediates Cardiac Regulation by the Activation of Sympathetic Nerves in a Rat Model of Myocardial Ischemia / 神经科学通报·英文版

Myocardial ischemia (MI) causes somatic referred pain and sympathetic hyperactivity, and the role of sensory inputs from referred areas in cardiac function and sympathetic hyperactivity remain unclear. Here, in a rat model, we showed that MI not only led to referred mechanical hypersensitivity on the forelimbs and upper back, but also elicited sympathetic sprouting in the skin of the referred area and C8-T6 dorsal root ganglia, and increased cardiac sympathetic tone, indicating sympathetic-sensory coupling. Moreover, intensifying referred hyperalgesic inputs with noxious mechanical, thermal, and electro-stimulation (ES) of the forearm augmented sympathetic hyperactivity and regulated cardiac function, whereas deafferentation of the left brachial plexus diminished sympathoexcitation. Intradermal injection of the α2 adrenoceptor (α2AR) antagonist yohimbine and agonist dexmedetomidine in the forearm attenuated the cardiac adjustment by ES. Overall, these findings suggest that sensory inputs from the referred pain area contribute to cardiac functional adjustment via peripheral α2AR-mediated sympathetic-sensory coupling.

A Remodelação do Sistema Nervoso Autônomo Cardíaco pode Desempenhar um Papel na Fibrilação Atrial: Um Estudo do Sistema Nervoso Autônomo e Receptores Miocárdicos / Cardiac Autonomic Nervous System Remodeling May Play a Role in Atrial Fibrillation: A Study of the Autonomic Nervous System and Myocardial Receptors

Resumo Fundamento Alterações do substrato elétrico e anatômico do coração são fatores que originam e perpetuam a fibrilação atrial (FA), porém, os mecanismos envolvidos não foram totalmente elucidados ainda. Objetivo: Avaliar o papel do remodelamento do sistema nervoso cardíaco intrínseco (SNCI), incluindo fibras nervosas e receptores muscarínicos e β-adrenérgicos, na FA permanente humana. Métodos Foram avaliadas 4 amostras em átrios de 13 corações obtidos em necrópsias de pacientes com doença cardíaca e FA permanente, e em 13 controles com as mesmas doenças, porém, sem FA. Utilizando imunoperoxidase e histomorfometria, quantificamos a densidade das fibras do SNCI, bem como a porcentagem positiva de miocárdio para receptores β-adrenérgicos 1, 2 e 3, receptor quinase 5 acoplado à proteína G (GRK-5), e receptores muscarínicos 1 a 5. Os resultados foram comparados usando ANOVA e ANOVA hierarquizada e ajustados pelo volume do átrio esquerdo e, para avaliação da expressão de receptores β e GRK-5, pelo uso de β-bloqueadores. Adotamos como significativo α = 0,05. Resultados Houve aumento na densidade das fibras ( p <0,01), especialmente nas fibras simpáticas ( p =0,02). Quanto aos receptores muscarínicos, só houve diferença nos M1, que estavam aumentados (5,87±4,52 vs 2,85±2,40; p =0,03). Quanto aos componentes do sistema adrenérgicos analisados, houve expressão aumentada de β-3 (37,41 vs 34,18, p =0,04) e GRK-5 (51,16 vs 47,66; p<0,01). O uso de β-bloqueadores não teve impacto na expressão de receptores beta. Conclusão O aumento na inervação do SNCI e a alteração na expressão de receptores em regiões suscetíveis de desencadear FA podem ter um papel na fibrilação atrial permanente.

Abstract Background The primary factors that originate and perpetuate atrial fibrillation (AF) are electrical and anatomical substrate alterations. However, the central mechanisms governing AF perpetuation have not been elucidated yet, which is reflected on the modest results of the treatment in patients with long persistent AF. Objective To evaluate if human intrinsic cardiac autonomic nervous system (ICANS) remodeling, including nervous system fibers and muscarinic and β-adrenergic receptors, play a role in permanent AF. Methods Heart necropsy samples from thirteen patients with heart disease and permanent AF and thirteen controls without AF were used. By using immunoperoxidase and histomorphometry quantification, we identified the following: the density of all fibers of the ICANS, sympathetic and parasympathetic fibers; and the percentage of myocardium positive for β-adrenergic receptors 1, 2 and 3; G protein-coupled receptor kinase-5 (GRK-5); and muscarinic receptors M1 to M5. The results were compared using ANOVA and nested ANOVA and were adjusted according to the left atrium volume for all variables, and β-blocker use to evaluate the expression of β-receptors and GRK-5. Results There was an overall increase in the density of fibers of the ICANS (p=0.006), especially in atrial sympathetic nerve fibers (p=0.017). Only M1 muscarinic receptors were increased (5.87 vs 2.35, p=0.032). For adrenergic receptors, the results were positive for increased expression of β-3 (37.41 vs 34.18, p=0.039) and GRK-5 (51.16 vs 47.66; p<0.001). β-blocker use had no impact on β-receptor expression. Conclusion Increased ICANS innervation and remodeling receptor expression in regions prone to triggering AF may play a role in permanent AF.

Is there neural and functional recovery after clip removal in cervical experimental sympathectomy? / Existe recuperação neural e funcional após a retirada de clipe quando da indução de simpatectomia cervical experimental?

ABSTRACT Background: The surgical treatment of hyperhidrosis by thoracic sympathectomy has brought, in addition to symptomatic relief for many, its main adverse effect: compensatory or reflex sweating. The clipping technique in place of the sympathetic nerve section gave rise to the hope of reversibility, but the positive results showed to be quite divergent, evidencing the academic deficiency regarding the study of this phenomenon. Aim: To observe micro and macroscopic damage caused by the polymer clip on sympathetic nerve of rabbits seven days after their clipping and the findings after three weeks of clip removal. Method: In this experimental study, 20 rabbits were divided into two groups of 10, group 1 (clipping) and group 2 (de-clipping). The right cervical sympathetic nerve of all animals was clamped with polymeric clip, and in group 2 the nerve was unclipped seven days later. Group 1 rabbits were induced to death on the 7th postoperative day, and group 2 on the 21st after removal of the polymer clip. Macroscopic variables were: clip appearance, presence of discontinuity lesion, infection and adhesions around the nerve. H&E was used in the evaluation of the phases and degree of the inflammatory process and presence of necrosis, and picrosirius red F3BA for quantification of collagen. Results: The cervical sympathetic nerve was intact, without necrosis or infection in all animals of the experiment; there were adhesions in both groups, being minimal in eight animals of each group and moderate or intense in two; the clip was completely closed in all animals at the 7th postoperative day; the inflammatory process shown was chronic, with monomorphonuclear predominance. There was no significant difference between groups regarding the intensity the inflammatory process, but the amount of collagen type I and type III was significantly higher in group 2. Conclusions: The injury caused by the polymer clip on the sympathetic nerve may be reversible, allowing functional return in the areas involved in the simulated cervical sympathectomy. Clipping of the cervical sympathetic nerve using a polymer clip does not cause discontinuity injury.

RESUMO Racional: O tratamento cirúrgico da hiperidrose pela simpatectomia torácica trouxe além do alívio sintomático para muitos, também seu principal efeito adverso: o suor compensatório ou reflexo. A técnica de clipagem do nervo simpático no lugar de sua secção deu margem à esperança de reversão do procedimento; porém, os resultados mostram-se bastante divergentes e pouco conclusivos Objetivo: Observar a lesão provocada pelo clipe de polímero em nervo simpático de coelhos sete dias após sua clipagem, comparando-a com os achados após três semanas da retirada do clipe. Método: Estudo experimental, com amostra formada por 20 coelhos, divididos em dois grupos de 10, sendo o grupo 1 chamado clipagem e o 2, desclipagem. Todos foram submetidos à clipagem do nervo simpático cervical direito com clipe polimérico, e no grupo 2 realizou-se a desclipagem sete dias após. Os coelhos do grupo 1 foram submetidos à eutanásia no 7º dia de pós-operatório, e os do grupo 2 no 21º dia após a remoção do clipe. Observou-se na macroscopia o aspecto do clipe, a presença de lesão de descontinuidade, infecção e aderências ao redor do nervo. Para estudo microscópico utilizou-se a coloração H&E na avaliação das fases, grau do processo inflamatório e presença de necrose, e a de picrosirius red F3BA para quantificação de colágeno. Resultados: O nervo simpático cervical foi identificado íntegro, sem necrose ou infecção em todos os animais do experimento; havia aderências em ambos os grupos, sendo mínimas em oito de cada grupo e moderadas ou intensas em dois; em toda a amostra o clipe encontrava-se completamente fechado no 7º dia de pós-operatório; o processo inflamatório presente foi do tipo crônico, com predomínio monomorfonuclear, não se observando diferença significativa em relação ao grau do processo inflamatório entre os grupos; porém, a quantidade de colágeno tanto do tipo I quanto do tipo III foi significativamente maior no grupo 2. Conclusões: A lesão provocada pelo clipe de polímero em nervo simpático pode ser reversível possibilitando o retorno funcional nas áreas envolvidas na simpatectomia cervical simulada. A clipagem do nervo simpático cervical com uso de clipe de polímero não causa lesão de descontinuidade.

Exercise training reduces sympathetic nerve activity and improves executive performance in individuals with obstructive sleep apnea

OBJECTIVE: To investigate the effects of exercise training (ET) on muscle sympathetic nerve activity (MSNA) and executive performance during Stroop Color Word Test (SCWT) also referred to as mental stress test. METHODS: Forty-four individuals with obstructive sleep apnea (OSA) and no significant co-morbidities were randomized into 2 groups; 15 individuals completed the control period, and 18 individuals completed the ET. Mini-mental state of examination and intelligence quotient were also assessed. MSNA assessed by microneurography, heart rate by electrocardiography, blood pressure (automated oscillometric device) were measured at baseline and during 3 min of the SCWT. Peak oxygen uptake (VO2 peak) was evaluated using cardiopulmonary exercise testing. Executive performance was assessed by the total correct responses during 3 min of the SCWT. ET consisted of 3 weekly sessions of aerobic exercise, resistance exercises, and flexibility (72 sessions, achieved in 40±3.9 weeks). RESULTS: Baseline parameters were similar between groups. Heart rate, blood pressure, and MSNA responses during SCWT were similar between groups (p>0.05). The comparisons between groups showed that the changes in VO2 (4.7±0.8 vs -1.2±0.4) and apnea-hypopnea index (-7.4±3.1 vs 5.5±3.3) in the exercise-trained group were significantly greater than those observed in the control group respectively (p<0.05) after intervention. ET reduced MSNA responses (p<0.05) and significantly increased the number of correct answers (12.4%) during SCWT. The number of correct answers was unchanged in the control group (p>0.05). CONCLUSIONS: ET improves sympathetic response and executive performance during SCWT, suggesting a prominent positive impact of ET on prefrontal functioning in individuals with OSA. ClinicalTrials.gov: NCT002289625.

Evaluación clínica de las disautonomías / Clinical evaluation of dysautonomia

INTRODUCCIÓN: Disfunción del sistema nervioso autonómico ocurre en enfermedades del sistema nervioso central y periférico. Es importante cuantificar el compromiso simpático y parasimpático, diagnosticar la disfunción, monitorizar la evolución y la respuesta a terapias. Las principales pruebas funcionales son las cardiovasculares y sudomotoras. Existen además exámenes para estudiar la disfunción autonómica en distintos órganos y que son específicos de las especialidades médicas respectivas. DESARROLLO: Se describen los síntomas, las pruebas funcionales y métodos de estudio a nivel cardiovascular: simpáticas vasomotoras (noradrenérgicas) y cardiovagales (colinérgicas) y las pruebas para la sudoración: sudomotoras simpáticas (colinérgicas). Se describen los síntomas y exámenes a nivel pupilar, urogenital y gastrointestinal. Se señala la utilidad de las pruebas funcionales autonómicas en el estudio de distintas patologías neurológicas. CONCLUSIONES: la evaluación conjunta de los hallazgos clínicos y de las pruebas funcionales autonómicas permiten determinar el nivel anatómico y el grado de severidad de la disfunción autonómica con un fundamento fisiopatológico.

INTRODUCTION: Autonomic dysfunction occurs in patients with central and peripheral nervous system diseases. It is important to quantify the sympathetic and parasympathetic involvement for the diagnosis of the autonomic failure, for follow up and evaluate the response to a specific treatment. The most important studies are cardiovascular and sudomotor functional tests. There are other tests for the study of autonomic dysfunction in different organs, that are specific to respectively medical specialty. DEVELOPMENT: we describe main symptoms, functional autonomic tests and other methods to study cardiovascular: sympathetic vasomotor (noradrenergic) and cardiovagal (cholinergic) and sudomotor: sympathetic (cholinergic) functions. We describe symptoms and tests for assessment pupillary, genitourinary and gastrointestinal autonomic dysfunction. The indications for autonomic function testing in the different clinical scenarios are reported. CONCLUSIONS: combined evaluation of clinical and tests of autonomic function results allow to obtain the level and severity of autonomic dysfunction based upon pathophysiological support.

Efecto del manejo farmacológico del sistema nervioso autónomo en la pancreatitis aguda inducida por el veneno de escorpión Tityus zulianus en un modelo ex vivo / Effect of the pharmacological management of the autonomic nervous system in the acute pancreatitis induced by the venom of Tityus zulianus scorpion in an ex vivo model

La pancreatitis es una de las consecuencias principales del envenenamiento escorpiónico producido por el género Tityus. El manejo farmacológico mediante el uso de agonistas y antagonistas α adrenérgicos en modelos experimentales in vivo e in vitro, permiten establecer una aproximación del papel del Sistema Nervioso Simpático (SNS) en el desarrollo de la pancreatitis. Objetivo: determinar el papel del SNS en el desarrollo de la pancreatitis aguda inducida por el veneno de escorpión Tityus zulianus (TzV), por medio del uso de simpaticolíticos como la clonidina y el prazosin. Métodos: La Extravasación de Proteínas Plasmáticas (EPP) en el páncreas se evaluó mediante el método de Azul de Evans (AE), modificado de Saria y Lundberg (1983) a 620 nm; n=3 ratones NIH en cada grupo experimental. Las comparaciones se hicieron por ANOVA de una vía y las pruebas post HOC por Tukey-Kramer. Resultados: Ambos fármacos (1mg/Kg), disminuyeron significativamente p< 0,01 (**) la EPP en el páncreas inducida por el TzV, en comparación con los animales inoculados solo con TzV. No hubo diferencias significativas entre los animales del grupo control y los grupos tratados con los fármacos más el TzV. Conclusiones: El efecto pancreatotóxico del TzV en ratones podría tener un componente autonómico dado que drogas simpaticolíticas al disminuir la actividad noradrenérgica reducen la magnitud del edema. Esto sugiere que ambos fármacos pueden usarse como estrategia terapéutica en estos casos(AU)

Pancreatitis is one of the main consequences of scorpionic poisoning produced by the genus Tityus. The pharmacological management through the use of agonists and α adrenergic antagonists in experimental models in vivo and in vitro, allow us to establish an approximation of the role of the Sympathetic Nervous System (SNS) in the development of pancreatitis. Objective: to determine the role of SNS in the development of acute pancreatitis induced by the scorpion venom Tityus zulianus (TzV), through the use of sympatholytics such as clonidine and prazosin. Methods: Plasma Protein Extravasation (PPE) in the pancreas was evaluated by the method of Evans Blue (EA), modified by Saria and Lundberg (1983) at 620 nm; n = 3 NIH mice in each experimental group. Comparisons were made by one-way ANOVA and post-HOC tests by Tukey-Kramer. Results: Both drugs (1mg / Kg) significantly decreased p <0.01 (**) the EPP in the pancreas induced by TzV, compared to animals inoculated only with TzV. There were no significant differences between the animals in the control group and the groups treated with drugs plus TzV. Conclusions: The pancreatotoxic effect of TzV in mice could have an autonomic component since sympatholytic drugs by decreasing noradrenergic activity reduce the magnitude of edema. This suggests that both drugs can be used as a therapeutic strategy in these cases(AU)

Hiperactividad simpática paroxística: una entidad subdiagnosticada: caso clínico / Paroxysmal sympathetic hyperactivity: report of one case

Paroxysmal sympathetic hyperactivity may appear after brain injury. Its clinical manifestations are sporadic and self-limited crisis of arterial hypertension, hyperthermia, tachycardia, hyperhidrosis, muscle tension, sialorrhea and mydriasis. These subside with the administration of morphine and beta-blockers. It may be caused by a dysautonomia leading to increased levels of catecholamines due to the lack of brain regulation. We report a 19 years-old man with a history of illicit drug and alcohol consumption, with a secondary axonal injury due to a cranioencephalic trauma. During hospitalization, he had recurrent, self-limited episodes of dysautonomia. An infectious cause was discarded. When morphine was administrated suspecting the presence of pain, the crisis subsided, which helped to establish the diagnosis of paroxysmal sympathetic hyperactivity.

Renal sympathetic denervation for resistant hypertension: where do we stand after more than a decade / Denervação simpática renal para hipertensão resistente: situação depois de mais de uma década

Abstract Despite the current availability of safe and efficient drugs for treating hypertension, a substantial number of patients are drug-resistant hypertensives. Aiming this condition, a relatively new approach named catheter-based renal denervation was developed. We have now a clinically relevant time window to review the efficacy of renal denervation for treating this form of hypertension. This short review addresses the physiological contribution of renal sympathetic nerves for blood pressure control and discusses the pros and cons of renal denervation procedure for the treatment of resistant hypertension.

Resumo Em que pese a atual disponibilidade de medicamentos seguros e eficientes para o tratamento da hipertensão, um número significativo de pacientes sofre de hipertensão arterial resistente a tratamento medicamentoso. Em vista dessa condição, foi desenvolvida uma abordagem relativamente nova, denominada denervação renal por cateter. Dispomos atualmente de uma janela de tempo clinicamente relevante para analisar a eficácia da denervação renal no tratamento dessa modalidade de hipertensão. A presente revisão aborda a contribuição fisiológica dos nervos renais simpáticos no controle da pressão arterial e discute os prós e contras do procedimento de denervação renal no tratamento da hipertensão resistente.

Tyrosine hydroxylase and ß2-adrenergic receptor expression in leukocytes of spontaneously hypertensive rats: putative peripheral markers of central sympathetic activity

The sympathetic nervous system (SNS) plays a fundamental role in the pathophysiology of cardiovascular diseases, including primary arterial hypertension. In this study, we aimed to investigate whether the expression of the rate-limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), and the β2-adrenergic receptor (β2-AR) in immune cells from peripheral blood, reflect central SNS activity in spontaneously hypertensive rats (SHR). TH expression in the lower brainstem and adrenal glands and β2-AR expression in the lower brainstem were analyzed by western blot analyses. In the leukocytes, TH and β2-AR expression was evaluated by flow cytometry before and after chronic treatment with the centrally-acting sympathoinhibitory drug clonidine. Western blot analyses showed increased TH and β2-AR expression in the lower brainstem and increased TH in adrenal glands from SHR compared to normotensive Wistar Kyoto rats (WKY). Lower brainstem from SHR treated with clonidine presented reduced TH and β2-AR levels, and adrenal glands had decreased TH expression compared to SHR treated with vehicle. Flow cytometry showed that the percentage of leukocytes that express β2-AR is higher in SHR than in WKY. However, the percentage of leukocytes that expressed TH was higher in WKY than in SHR. Moreover, chronic treatment with clonidine normalized the levels of TH and β2-AR in leukocytes from SHR to similar levels of those of WKY. Our study demonstrated that the percentage of leukocytes expressing TH and β2-AR was altered in arterial hypertension and can be modulated by central sympathetic inhibition with clonidine treatment.

Review of the health benefits of habitual consumption of miso soup: focus on the effects on sympathetic nerve activity, blood pressure, and heart rate

High salt intake increases blood pressure, and dietary salt intake has been clearly demonstrated to be associated with hypertension incidence. Japanese people consume higher amounts of salt than Westerners. It has been reported that miso soup was one of the major sources of daily salt intake in Japanese people. Adding salt is indispensable to make miso, and therefore, in some cases, refraining from miso soup is recommended to reduce dietary salt intake. However, recent studies using salt-sensitive hypertensive models have revealed that miso lessens the effects of salt on blood pressure. In other word, the intake of miso dose not increase the blood pressure compared to the equivalent intake of salt. In addition, many clinical observational studies have demonstrated the absence of a relationship between the frequency of miso soup intake and blood pressure levels or hypertension incidence. The mechanism of this phenomenon seen in the subjects with miso soup intake has not been fully elucidated yet. However, in basic studies, it was found that the ingredients of miso attenuate sympathetic nerve activity, resulting in lowered blood pressure and heart rate. Therefore, this review focused on the differences between the effects of miso intake and those of the equivalent salt intake on sympathetic nerve activity, blood pressure, and heart rate.

Mu-opioid receptors in the paraventricular nucleus regulate ejaculatory behaviors via the sympathetic nerve system in male rats / 中华男科学杂志

Objective@#To explore the effects of the mu-opioid receptor (MOR) in the paraventricular nucleus (PVN) on the ejaculatory behaviors of male rats and its potential mechanisms.@*METHODS@#Male SD rats with normal ejaculation ability were mated with female ones in hormone-induced estrus. After bilateral PVN microinjection of D-Ala-2-Me-Phe-4-Gly-ol enkephalin (DAGO) or D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) with an inserted catheter, the male animals were observed for mount latency (ML), mount frequency (MF), intromission latency (IL), intromission frequency (IF), ejaculation latency (EL), ejaculation frequency (EF), post-ejaculation interval (PEI), and intromission ratio (IR). The lumbar sympathetic nerve activity (LSNA) of the rats was recorded using the PowerLab data acquisition hardware device, and the levels of norepinephrine (NE) in the peripheral plasma were measured by ELISA following microinjection of saline or different doses of DAGO or CTAP.@*RESULTS@#Neither CTAP nor DGAO significantly affected the ML of the male rats (P > 0.05). DGAO remarkably increased IF (P < 0.01) and MF (P < 0.01), prolonged IL (P < 0.01), EL (P < 0.01) and PEI (P < 0.01), and reduced EF (P <0.01) and IR (P < 0.05). On the contrary, CTAP markedly decreased IF (P < 0.01) and MF (P < 0.01), shortened IL (P < 0.01), EL (P < 0.01) and PFI (P < 0.01), and elevated EF (P < 0.01) and IR (P < 0.01). Additionally, DAGO decreased LSNA in a dose-dependent manner and reduced the NE level in the peripheral plasma. CTAP, however, not only offset the effects of DAGO on LSNA, but also significantly increased LSNA.@*CONCLUSIONS@#MOR in PVN inhibits ejaculatory behaviors in male rats by weakening LSNA, which has provided some theoretical evidence for the use of highly selective opioids in the treatment of premature ejaculation.

Evaluation of cardiac autonomic modulation using symbolic dynamics after cardiac transplantation

Abstract Objective: To characterize the behavior of cardiac autonomic modulation in individuals with different times after orthotopic heart transplantation (HTx) using symbolic dynamics analysis. Methods: Sixty patients were evaluated after HTx. We recorded their instantaneous R-R intervals (RRi) by cardiac monitor Polar® RS800CX™ (Polar Electro Oy, Kempele, Finland) for 10 minutes. The same sequence of RRi with 256 consecutive beats was used to perform spectral analysis and symbolic dynamics analysis. We used hierarchical clustering to form groups. One-way analysis of variance (ANOVA) (with Holm-Sidak method) or one-way Kruskal-Wallis test (with Dunn´s post-hoc test) was used to analyze the difference between groups. Linear correlation analysis between variables was performed using Pearson's or Spearman's tests. P-value < 0.05 was considered statistically significant. Results: The 0V% index increased, the 2UV% index and the normalized complexity index decreased with an increase of HTx postoperative time. There were a negative correlation between complexity indexes and 0V% and a positive correlation between complexity indexes and 2UV%. Conclusion: Symbolic dynamics indexes were able to show a specific cardiac autonomic modulation pattern for HTx recipients with different postoperative times.

Acute Physical Stress Preconditions the Heart Against Ischemia/Reperfusion Injury Through Activation of Sympathetic Nervous System / Estresse Físico Agudo Precondiciona o Coração Contra a Injúria por Isquemia/Reperfusão Através da Ativação do Sistema Nervoso Simpático

Abstract Background: Stress is defined as a complicated state that related to homeostasis disturbances, over-activity of the sympathetic nervous system and hypothalamus-pituitary-adrenal axis responses. Cardiac preconditioning reduces myocardial damages. Objective: This study was designed to assess the cardioprotective effects of acute physical stress against ischemia/reperfusion (I/R) injury through the activation of the sympathetic nervous system. Methods: Thirty-two male Wistar rats were divided into four groups; (1) IR (n = 8): rats underwent I/R, (2) Acute stress (St+IR) (n = 8): physical stress induced 1-hour before I/R, (3) Sympathectomy (Symp+IR) (n = 8): chemical sympathectomy was done 24-hours before I/R and (4) Sympathectomy- physical stress (Symp+St+IR) (n = 8): chemical sympathectomy induced before physical stress and I/R. Chemical sympathectomy was performed using 6-hydroxydopamine (100 mg/kg, sc). Then, the hearts isolated and located in the Langendorff apparatus to induce 30 minutes ischemia followed by 120 minutes reperfusion. The coronary flows, hemodynamic parameters, infarct size, corticosterone level in serum were investigated. P < 0.05 demonstrated significance. Results: Physical stress prior to I/R could improve left ventricular developed pressure (LVDP) and rate product pressure (RPP) of the heart respectively, (63 ± 2 versus 42 ± 1.2, p < 0.05, 70 ± 2 versus 43 ± 2.6, p < 0.05) and reduces infarct size (22.16 ± 1.3 versus 32 ± 1.4, p < 0.05) when compared with the I/R alone. Chemical sympathectomy before physical stress eliminated the protective effect of physical stress on I/R-induced cardiac damages (RPP: 21 ± 6.6 versus 63 ± 2, p < 0.01) (LVDP: 38 ± 4.5 versus 43 ± 2.6, p < 0.01) (infarct size: 35 ± 3.1 versus 22.16 ± 1.3, p < 0.01). Conclusion: Findings indicate that acute physical stress can act as a preconditional stimulator and probably, the presence of sympathetic nervous system is necessary.

Resumo Fundamento: O estresse é definido como um estado complicado de distúrbios da homeostase, hiperatividade do sistema nervoso simpático e das respostas do eixo hipotálamo-hipófise-adrenal. O pré-condicionamento cardíaco diminui os danos do miocárdio. Objetivo: Esse estudo avaliou os efeitos cardioprotetores do estresse físico agudo contra a lesão por isquemia-reperfusão (I/R) através da ativação do sistema nervoso simpático. Métodos: Trinta e dois ratos machos Wistar foram divididos em quatro grupos; (1) IR (n = 8): ratos submetidos a I/R, (2) Estresse agudo (St+IR) (n = 8): estresse físico induzido 1 hora antes da I/R, (3) Simpatectomia (Symp+IR) (n = 8): a simpatectomia química foi realizada 24 horas antes da I/R e (4) Simpatectomia-estresse físico (Symp+St+IR) (n = 8): simpatectomia induzida antes do estresse físico e da I/R. A simpatectomia química foi realizada com 6-hidroxidopamina (100 mg/kg, SC). Em seguida, os corações foram isolados e colocados em aparato de Lagendorff por 30 minutos para induzir isquemia, seguida de reperfusão por 120 minutos. Os fluxos coronarianos, os parâmetros hemodinâmicos, o tamanho do infarto e os níveis de corticosterona plasmática foram investigados. Valores de p < 0,05 foram considerados significativos. Resultados: O estresse físico anterior à I/R pode melhorar a pressão desenvolvida no ventrículo esquerdo (PDVE) e duplo produto (DP), respectivamente, (63 ± 2 versus 42 ± 1,2, p < 0,05, 70 ± 2 versus 43 ± 2,6, p < 0,05) e reduzir o tamanho do infarto (22,16 ± 1,3 versus 32±1,4, p < 0,05) quando comparado com a I/R isoladamente. A simpatectomia química antes do estresse físico eliminou o efeito protetor do estresse físico sobre os danos cardíacos induzidos pela I/R (DP: 21 ± 6,6 versus 63 ± 2, p < 0,01) (PDVE: 38 ± 4,5 versus 43 ± 2,6, p < 0,01) (tamanho do infarto: 35 ± 3,1 versus 22,16 ± 1,3, p < 0,01). Conclusão: Os achados indicam que o estresse físico agudo pode funcionar como um estimulador pré-condicional e, provavelmente, a presença do sistema nervoso simpático é necessária.

Prognostic value of coupling interval, prematurity index and heart rate variability in Boxer dogs / Valor prognóstico do intervalo de acoplamento, índice de prematuridade e variabilidade da frequência cardíaca em cães da raça Boxer

Boxer dogs with arrhythmogenic right ventricular cardiomyopathy (ARVC) can experience sudden cardiac death regardless of presence/absence of clinical signs. The aims of this retrospective study were two-fold: 1) to investigate the coupling interval (CI) and prematurity index (PI) of ventricular arrhythmias (VA), and the heart rate variability (HRV) in Boxers, and 2) to evaluate their impact on overall survival time. The first 24-hour Holter 36 client-owned Boxer dogs meeting inclusion/exclusion criteria were evaluated for the number, morphology, site of origin, complexity, CI and PI, of ventricular premature complexes (VPCs), and time domain HRV. The effect on survival was assessed, considering the presence/absence of ventricular tachycardia (VT), and syncope. All-cause mortality was considered as the end-point, with median survival times being obtained by Kaplan-Meier analyses and compared by log-rank test. Polymorphic VPCs were more common in symptomatic dogs than asymptomatic. VPCs in dogs with VT were less premature, due to the influence of heart rate on PI despite comparable CI. The PI and mean heart rate (HRme) were significantly different between VT and non-VT dogs but did not discriminate adequately between groups as standalone tests. Median survival time was shorter in Boxer dogs with VT (463 vs 1645 days, HR: 4.31, P=0.03). The HRV parameters, SDNN and SDANN, were both associated with prognosis. The CI and PI were not demonstrated to be prognostic surrogates in Boxer dogs with VA. HRme≥112bpm is 100% sensitive but only 46% specific for detecting VT in Boxers on the 24-hour Holter. Presence of VT, SDNN≤245ms, or SDANN≤134ms at the time of the first 24-hour Holter was associated with a shorter survival.(AU)

Cães da raça Boxer com cardiomiopatia arritmogênica do ventrículo direito (CAVD) podem apresentar morte súbita independentemente da presença/ausência de sinais clínicos. Os objetivos desse estudo retrospectivo foram: 1) investigar o intervalo de acoplamento (IA) e o índice de prematuridade (IP) das arritmias ventriculares e a variabilidade da frequência cardíaca (VFC) em Boxers, e 2) avaliar o impacto de tais características sob o tempo de sobrevida global. O primeiro Holter de 24 horas de 36 Boxers selecionados para os critérios de inclusão/exclusão foram avaliados para o número, morfologia, local de origem, complexidade, IA e IP dos complexos ventriculares prematuros (CVPs) e da VFC no domínio do tempo. O efeito na sobrevida foi avaliado, considerado a presença/ausência de taquicardia ventricular (TV), e síncope. O desfecho final foi a mortalidade global, com o tempo de sobrevida mediano sendo obtido pela análise de Kaplan-Meier e comparado pelo teste de log-rank. CVPs polimórficos foram mais comuns em cães sintomáticos. Os CVPs em Boxers com TV foram menos prematuros, devido à influência da frequência cardíaca (FC) sobre o IP, apesar de IA comparáveis. O IP e a FC média diferiram entre os cães com TV e os sem, mas não discriminam adequadamente os grupos como variáveis isoladas. A sobrevida global foi menor nos cães com TV (463 dias vs 1645 dias, HR=4,31, P=0,03). Os parâmetros da VFC, SDNN e SDANN, foram associados ao prognóstico. O IA e o IP não possuem valor prognóstico em Boxers com arritmias ventriculares. A FC média ≥112bpm é 100% sensível, mas apenas 46% específica para detectar Boxers com TV no Holter de 24 horas. A presença de TV, SDNN≤245ms, ou SDANN≤134ms no momento do primeiro Holter de 24 horas estão associados a menor sobrevida global no Boxer.(AU)

Sympatho-Vagal Imbalance is Associated with Sarcopenia in Male Patients with Heart Failure / Desequilíbrio Simpático-Vagal está Associado com Sarcopenia em Pacientes do Sexo Masculino com Insuficiência Cardíaca

Abstract Background: Resting sympathetic hyperactivity and impaired parasympathetic reactivation after exercise have been described in patients with heart failure (HF). However, the association of these autonomic changes in patients with HF and sarcopenia is unknown. Objective: The aim of this study was to evaluate the impact of autonomic modulation on sarcopenia in male patients with HF. Methods: We enrolled 116 male patients with HF and left ventricular ejection fraction < 40%. All patients underwent a maximal cardiopulmonary exercise testing. Maximal heart rate was recorded and delta heart rate recovery (∆HRR) was assessed at 1st and 2nd minutes after exercise. Muscle sympathetic nerve activity (MSNA) was recorded by microneurography. Dual-energy X-ray absorptiometry was used to measure body composition and sarcopenia was defined by the sum of appendicular lean muscle mass (ALM) divided by height in meters squared and handgrip strength. Results: Sarcopenia was identified in 33 patients (28%). Patients with sarcopenia had higher MSNA than those without (47 [41-52] vs. 40 [34-48] bursts/min, p = 0.028). Sarcopenic patients showed lower ∆HRR at 1st (15 [10-21] vs. 22 [16-30] beats/min, p < 0.001) and 2nd min (25 [19-39] vs. 35 [24-48] beats/min, p = 0.017) than non-sarcopenic. There was a positive correlation between ALM and ∆HRR at 1st (r = 0.26, p = 0.008) and 2nd min (r = 0.25, p = 0.012). We observed a negative correlation between ALM and MSNA (r = -0.29, p = 0.003). Conclusion: Sympatho-vagal imbalance seems to be associated with sarcopenia in male patients with HF. These results highlight the importance of a therapeutic approach in patients with muscle wasting and increased peripheral sympathetic outflow.

Resumo Fundamento: Hiperatividade simpática de repouso e uma reativação parassimpática diminuída pós-exercício têm sido descritas em pacientes com insuficiência cardíaca (IC). No entanto, a associação dessas alterações autonômicas em pacientes com IC sarcopênicos ainda não são conhecidas. Objetivo: O objetivo deste estudo foi avaliar o impacto da modulação autonômica sobre sarcopenia em pacientes com IC do sexo masculino. Métodos: Foram estudados 116 pacientes com IC e fração de ejeção ventricular esquerda inferior a 40%. Todos os pacientes foram submetidos ao teste de exercício cardiopulmonar máximo. A frequência cardíaca máxima foi registrada, e o delta de recuperação da frequência cardíaca (∆RFC) foi avaliado no primeiro e no segundo minuto após o exercício. A atividade nervosa simpática muscular (ANSM) foi registrada por microneurografia. A Absorciometria Radiológica de Dupla Energia foi usada para medir composição cpororal, e a sarcopenia definida como a soma da massa muscular apendicular (MMA) dividida pela altura em metros ao quadrado e força da mão. Resultados: A sarcopenia foi identificada em 33 pacientes (28%). Os pacientes com sarcopenia apresentaram maior ANSM que aqueles sem sarcopenia - 47 (41-52) vs. 40 (34-48) impulsos (bursts)/min, p = 0,028). Pacientes sarcopênicos apresentaram ∆RFC mais baixo no primeiro [15 (10-21) vs. 22 (16-30) batimentos/min, p < 0,001) e no segundo [25 (19-39) vs. 35 (24-48) batimentos/min, p = 0,017) minuto que pacientes não sarcopênicos. Observou-se uma correlação positiva entre a MMA e a ANSM (r = -0,29; p = 0,003). Conclusão: Um desequilíbrio simpático-vagal parece estar associado com sarcopenia em pacientes com IC do sexo masculino. Esses resultados destacam a importância de uma abordagem terapêutica em pacientes com perda muscular e fluxo simpático periférico aumentado.