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1.
Clin Nutr ; 40(6): 4490-4499, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33483182

RESUMO

BACKGROUND & AIMS: Sarcopenia is a multifactorial syndrome resulting in a decrease in both muscle mass and function. Little is known about the prevalence and prognostic impact of sarcopenia in patients with acutely decompensated chronic heart failure (ADHF). We aimed to evaluate the prevalence (main endpoint) and impact of sarcopenia on ADHF patients. METHODS: 140 ADHF patients were enrolled between November 2014 and September 2018 in a multicenter prospective longitudinal study. A similar, independent multi-departmental cross-sectional study in 165 ADHF patients was used for external validation of prevalence data. All subjects were assessed on the European Working Group on Sarcopenia criteria. RESULTS: Ninety-one patients (65%) had sarcopenia (vs. 53.6% in the external replication regional cohort). Patients with sarcopenia were older and more likely to have eGFR <60 ml/min/1.73 m2 (p < 0.001 and p = 0.002). Sarcopenia was associated with impaired functional status [lower 6 min walking test (220 ± 108 vs. 279 ± 170, p = 0.03) and 4 m gait speed (0.56 ± 0.24 vs. 0.80 ± 0.37, p < 0.001)] and autonomy [Instrumental activities of daily living: 6.7 ± 1.4 vs. 7.3 ± 1.2, p = 0.005]. Over up to 4 years' follow-up, 30 cardiovascular (CV) deaths and 42 non-CV deaths occurred. In a multivariable analysis, sarcopenia was associated with time to first non-CV hospitalization (hazard ratio 1.93; 95% confidence interval 1.14-3.24; p = 0.014) but not with any other hospitalization, any mortality endpoint, or a composite endpoint of CV death and HF hospitalization. CONCLUSIONS: The prevalence of sarcopenia in ADHF patients is high and associated with greater risk of non-CV hospitalizations, highlighting the importance of identifying and managing the condition in a multidisciplinary approach. CLINICAL TRIAL REGISTRATION: NCT03153774.


Assuntos
Insuficiência Cardíaca/complicações , Sarcopenia/complicações , Sarcopenia/epidemiologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Força da Mão , Hospitalização , Humanos , Estudos Longitudinais , Masculino , Prevalência , Estudos Prospectivos , Sarcopenia/diagnóstico
2.
Eur J Phys Rehabil Med ; 56(1): 73-81, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31489810

RESUMO

BACKGROUND: Resection surgery is the main treatment for non-small cell lung cancer (NSCLC). Postoperative complications and mortality are mostly linked to respiratory failure consecutive to respiratory muscle overload. AIM: We aimed to evaluate the effect of preoperative respiratory muscle endurance training (RMET) on respiratory muscle capacity and postoperative complications in patients undergoing NSCLC resection. DESIGN: Randomized controlled trial. SETTING: French university hospital. POPULATION: Patients eligible for NSCLC resection. METHODS: The training group (T group) performed a 3-week preoperative RMET added to usual chest physical therapy while the control group (C group) had only the latter. The primary outcome was the change in respiratory muscle endurance. Secondary outcomes were postoperative complications and mortality. Assessments were performed similarly at baseline and after the intervention. We conducted multivariable analyses with analysis of covariance (ANCOVA) taking into account baseline values for isocapnic hyperpnoea endurance test, exercise capacity and pulmonary function tests. The number of pulmonary postoperative complication was analyzed by Fisher-exact test. RESULTS: We included 26 patients with NSCLC (14 in the T group and 12 in the C group). Respiratory muscle endurance significantly increased in the T group after the RMET compared with C group (+229±199 vs. -5±371 sec, P=0.001). This increase was associated with a significantly lower number of pulmonary postoperative complications (2 vs. 10, P=0.037). CONCLUSIONS: Preoperative RMET improved respiratory muscle endurance and decreased pulmonary postoperative complications after surgery for NSCLC. These positive results obtained after RMET may help improve the perioperative course for such patients. These results should be confirmed in larger randomized controlled trials, including higher number of patients especially with altered respiratory muscle function. CLINICAL REHABILITATION IMPACT: Low-cost and easy to perform, RMET training could serve as complementary tool to usual chest physical therapy, before lung resection surgery.


Assuntos
Exercícios Respiratórios/métodos , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Treino Aeróbico/métodos , Feminino , Humanos , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Testes de Função Respiratória
3.
BMJ Open ; 9(5): e024389, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133575

RESUMO

INTRODUCTION: Intrathoracic shunt quantification is a major factor for appropriate clinical management of heart and pulmonary diseases. Intracardiac shunts quantified by pulmonary to systemic output ratio (Qp/Qs) are generally assessed by Doppler echocardiography, MRI or catheterisation. Recently, some authors have suggested the concomitant use of thoracic bioimpedance (TB) and inert gas rebreathing (IGR) techniques for shunt quantification. The purpose of this study is to validate the use of this approach under conditions where shunt fraction is directly quantified such as in patients with isolated atrial septal defect (ASD). METHODS AND ANALYSIS: This trial is a prospective, observational single-centre, non-blinded study of adults seen for percutaneous closure of ASD. Qp/Qs ratio will be directly measured by Doppler echocardiography and direct Fick. IGR and TB will be used simultaneously to measure the cardiac output before and after closure: the ratio of outputs measured by IGR and TB reflecting the shunt fraction. The primary outcome will be the comparison of shunt values measured by TB-IGR and Doppler echocardiography. ETHICS AND DISSEMINATION: The study has been approved by an independent Research Ethics Committee (2017-A03149-44 Fr) and registered as an official clinical trial. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03437148; Pre-results.


Assuntos
Testes Respiratórios/métodos , Cardiografia de Impedância/métodos , Comunicação Interatrial/cirurgia , Gases Nobres/farmacocinética , Débito Cardíaco , Ecocardiografia Doppler , Comunicação Interatrial/diagnóstico , Comunicação Interatrial/diagnóstico por imagem , Comunicação Interatrial/fisiopatologia , Humanos , Consumo de Oxigênio , Resultado do Tratamento
4.
BMJ Open ; 7(11): e017307, 2017 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-29133320

RESUMO

INTRODUCTION: Surgery is the standard curative treatment for lung cancer but is only possible in patients with local tumour and preserved exercise capacity. Improving fitness before surgery can reduce postoperative complications and mortality. However, preoperative rehabilitation remains difficult to implement for several reasons. We aim to investigate the effectiveness of an intensive 3-week home-based preoperative exercise training programme on hospital discharge ability, postoperative complications and physical performance in patients with chronic obstructive pulmonary disease (COPD) who are eligible for lung cancer surgery. METHODS AND ANALYSIS: We designed a multicentre randomised controlled trial. The randomisation sequence will be generated and managed electronically by a research manager independent of assessments or interventions. We will recruit 90 patients with COPD and a diagnosis of lung cancer from four university hospitals. The rehabilitation group (R group) will receive a standardised preoperative home exercise programme for 3 weeks, combining both high-intensity training and usual physical therapy. The R group will perform 15 training sessions over 3 weeks on a cycloergometer. A physical therapist experienced in pulmonary rehabilitation will visit the patient at home and supervise one session a week. The R group will be compared with a control group receiving preoperative usual physical therapy only. The primary outcome will be hospital discharge ability assessed with a 10-item list. Secondary outcomes will be postoperative course (complication rate and mortality) as well as pulmonary function, exercise capacity and quality of life assessed 1 month before and the day before surgery. ETHICS AND DISSEMINATION: This protocol has been approved by the French health authority for research (2016-A00622-49) and the research ethics committee/institutional review board (AU1267). Adverse events that occur during the protocol will be reported to the principal investigator. The results will be published in an international peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03020251.


Assuntos
Terapia por Exercício/métodos , Neoplasias Pulmonares/diagnóstico , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/reabilitação , Tolerância ao Exercício , França , Humanos , Modelos Logísticos , Neoplasias Pulmonares/cirurgia , Alta do Paciente , Estudos Prospectivos , Qualidade de Vida , Projetos de Pesquisa , Teste de Caminhada
5.
BMJ Open ; 6(12): e012876, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27927660

RESUMO

INTRODUCTION: Perioperative chemotherapy is the gold standard treatment of the resectable gastro-oesophageal adenocarcinoma. However, 70% of patients cannot receive the complete sequence because of a postoperative complication or a decrease in functional and nutritional reserves. Recently, a new concept appeared in digestive surgery: prehabilitation. This interventional process consists of patient preparation, between surgical consultation and surgery, and is based on 3 components: (1) physical management, (2) nutritional care and (3) psychological care. Prehabilitation should decrease postoperative complications and improve nutritional and physical status during the preoperative and postoperative periods. Therefore, it is becoming essential to evaluate the effect of prehabilitation, compared to conventional care, on the percentage of patients reaching the complete oncological treatment. METHODS AND ANALYSIS: The PREHAB trial aimed to evaluate the efficacy of prehabilitation compared to conventional care, in patients with gastro-oesophageal cancer with perioperative chemotherapy. This trial is a prospective, randomised, controlled, open-blind and interventional study in 4 centres. Patients (n=60 per group) will be randomly assigned for management with either prehabilitation or conventional care. The primary outcome is the percentage of patients reaching the complete oncological treatment decided in a multidisciplinary tumour board. The secondary outcomes are the postoperative morbidity, disease-free survival, overall survival, feasibility of the protocol, length of stay, variation of the functional reserve after the preoperative chemotherapy (defined by the VO2peak, ventilatory threshold and 6-min walk test), preoperative and postoperative nutritional status, preoperative anxiety, quality of life, 30-day and 90-day mortality and cumulative dose of cytotoxic treatment received. ETHICS AND DISSEMINATION: The study was approved by an independent medical ethics committee (IRB00008526, CPP Sud-Est VI, Clermont-Ferrand, France) and by the competent French authority (ANSM, Saint Denis, France) and registered on Clinicaltrial.gov. The results will be disseminated in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT02780921.


Assuntos
Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Esofágicas/terapia , Complicações Pós-Operatórias/prevenção & controle , Cuidados Pré-Operatórios , Neoplasias Gástricas/terapia , Adenocarcinoma/complicações , Adenocarcinoma/fisiopatologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Esofágicas/complicações , Neoplasias Esofágicas/fisiopatologia , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Nutricional , Cuidados Pré-Operatórios/métodos , Estudos Prospectivos , Qualidade de Vida , Neoplasias Gástricas/complicações , Neoplasias Gástricas/fisiopatologia , Resultado do Tratamento
6.
Ann Thorac Surg ; 102(3): e195-e196, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27549540

RESUMO

Acquired emphysema is a rare pathology in pediatrics. We report the case of a patient born at term with a neonatal respiratory distress, which had required mechanical ventilation. She developed gradually chronic obstructive pulmonary disease with severe emphysematous lesions, respiratory failure and functional impairments. Bilateral emphysema resection, performed at 16 years old, allowed major functional benefits at rest and during exercise. We present the results of respiratory functional evaluations, walk tests and maximal exercise tests (including measure of dynamic hyperinflation) before and after surgery, which highlights that surgery is a successful option in the treatment of compressive emphysema in childhood.


Assuntos
Pneumonectomia/métodos , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Doença Pulmonar Obstrutiva Crônica/cirurgia , Qualidade de Vida , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Adolescente , Progressão da Doença , Feminino , Seguimentos , Humanos , Medidas de Volume Pulmonar , Cuidados Pós-Operatórios/métodos , Respiração Artificial , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Testes de Função Respiratória , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
7.
Drug Des Devel Ther ; 9: 3589-97, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26203225

RESUMO

BACKGROUND: It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients. MATERIALS AND METHODS: Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate-malate or N, N, N', N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate-malate as substrate. RESULTS: As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate-malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD-ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters. CONCLUSION: In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.


Assuntos
Eletrólise , Mitocôndrias/metabolismo , Oxigênio/metabolismo , Água/química , Difosfato de Adenosina/metabolismo , Animais , Ácido Glutâmico/metabolismo , Malatos/metabolismo , Masculino , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar , Saponinas/farmacologia
8.
Chin Clin Oncol ; 4(4): 40, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26730752

RESUMO

BACKGROUND: Whether prophylactic tracheotomy can shorten the duration of mechanical ventilation (MV) in high risk patients eligible for lung cancer resection. The objective was to compare duration of MV and outcome in 39 patients randomly assigned to prophylactic tracheotomy or control. METHODS: Prospective randomized controlled, single-center trial (ClinicalTrials.gov Identifier: NCT01053624). The primary outcome measure was the cumulative number of MV days after operation until discharge. The secondary outcome measures were the 60 days mortality rate, the ICU and the hospital length of stay, the incidence of postoperative respiratory, cardiac and general complications, the reventilation rate, the need of noninvasive ventilation (NIV), the need of a tracheotomy in control group and the tracheal complications. RESULTS: The duration of MV was not significantly different between the tracheotomy group (3.5±6 days) and the control group (4.7±9.3 days) (P=0.54). Among patients needing prolonged MV >4 days, tracheotomy patients had a shortened duration of MV than control patients (respectively 11.4±7.1 and 20.4±9.6 days, P=0.04). The rate of respiratory complications were significantly lower in the tracheotomy group than in the control group (28% vs. 51%, P=0.03). Six patients (15%) needed a postoperative tracheotomy in the control group because of a prolonged MV >7 days. Tracheotomy was associated with a reduced need of NIV (P=0.04). There was no difference in 60-day mortality rate, cardiac complications, intensive care unit and hospital length of stay. No death was related with the tracheotomy. CONCLUSIONS: Prophylactic tracheotomy in patients with ppo FEV1 <50% who underwent thoracotomy for lung cancer resection provided benefits in terms of duration of prolonged MV and respiratory complications but was not associated with a decreased mortality rate, ICU and hospital length of stay and non-respiratory complications.


Assuntos
Neoplasias Pulmonares/cirurgia , Pulmão/cirurgia , Pneumonectomia , Respiração Artificial , Doenças Respiratórias/terapia , Toracotomia , Traqueotomia , Idoso , Feminino , Volume Expiratório Forçado , França , Humanos , Tempo de Internação , Pulmão/patologia , Pulmão/fisiopatologia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pneumonectomia/efeitos adversos , Pneumonectomia/mortalidade , Estudos Prospectivos , Recuperação de Função Fisiológica , Respiração Artificial/efeitos adversos , Doenças Respiratórias/etiologia , Doenças Respiratórias/mortalidade , Doenças Respiratórias/fisiopatologia , Fatores de Risco , Toracotomia/efeitos adversos , Toracotomia/mortalidade , Fatores de Tempo , Traqueotomia/efeitos adversos , Traqueotomia/mortalidade , Resultado do Tratamento
9.
Muscle Nerve ; 50(5): 803-11, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24639213

RESUMO

INTRODUCTION: The effect of eccentric (ECC) versus concentric (CON) training on metabolic properties in skeletal muscle is understood poorly. We determined the responses in oxidative capacity and mitochondrial H2 O2 production after eccentric (ECC) versus concentric (CON) training performed at similar mechanical power. METHODS: Forty-eight rats performed 5- or 20-day eccentric (ECC) or concentric (CON) training programs. Mitochondrial respiration, H2 O2 production, citrate synthase activity (CS), and skeletal muscle damage were assessed in gastrocnemius (GAS), soleus (SOL) and vastus intermedius (VI) muscles. RESULTS: Maximal mitochondrial respiration improved only after 20 days of concentric (CON) training in GAS and SOL. H2 O2 production increased specifically after 20 days of eccentric ECC training in VI. Skeletal muscle damage occurred transiently in VI after 5 days of ECC training. CONCLUSIONS: Twenty days of ECC versus CON training performed at similar mechanical power output do not increase skeletal muscle oxidative capacities, but it elevates mitochondrial H2 O2 production in VI, presumably linked to transient muscle damage.


Assuntos
Mitocôndrias Musculares/fisiologia , Músculo Esquelético/ultraestrutura , Estresse Oxidativo/fisiologia , Condicionamento Físico Animal/fisiologia , Difosfato de Adenosina/metabolismo , Animais , Índice de Massa Corporal , Citrato (si)-Sintase/metabolismo , Creatina Quinase/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácido Láctico/sangue , Masculino , Ventilação Voluntária Máxima , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar , Ácido Succínico , Fatores de Tempo
10.
Lung Cancer ; 82(3): 383-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24161719

RESUMO

Oxidative stress appears to play an essential role as a secondary messenger in the normal regulation of a variety of physiological processes, such as apoptosis, survival, and proliferative signaling pathways. Oxidative stress also plays important roles in the pathogenesis of many diseases, including aging, degenerative disease, and cancer. Among cancers, lung cancer is the leading cause of cancer in the Western world. Lung cancer is the commonest fatal cancer whose risk is dependent on the number of cigarettes smoked per day as well as the number of years smoking, some components of cigarette smoke inducing oxidative stress by transmitting or generating oxidative stress. It can be subdivided into two broad categories, small cell lung cancer and non-small-cell lung cancer, the latter is the most common type. Distinct measures of primary and secondary prevention have been investigated to reduce the risk of morbidity and mortality caused by lung cancer. Among them, it seems that physical activity and nutrition have some beneficial effects. However, physical activity can have different influences on carcinogenesis, depending on energy supply, strength and frequency of exercise loads as well as the degree of exercise-mediated oxidative stress. Micronutrient supplementation seems to have a positive impact in lung surgery, particularly as an antioxidant, even if the role of micronutrients in lung cancer remains controversial. The purpose of this review is to examine lung cancer in relation to oxidative stress, physical activity, and nutrition.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Atividade Motora , Fenômenos Fisiológicos da Nutrição , Estresse Oxidativo , Animais , Antioxidantes/uso terapêutico , Carcinogênese , Carcinoma Pulmonar de Células não Pequenas/prevenção & controle , Humanos , Neoplasias Pulmonares/prevenção & controle , Micronutrientes/uso terapêutico , Risco , Fumar
11.
Sports Med ; 43(6): 483-512, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23657934

RESUMO

Eccentric (ECC) exercise is classically used to improve muscle strength and power in healthy subjects and athletes. Due to its specific physiological and mechanical properties, there is an increasing interest in employing ECC muscle work for rehabilitation and clinical purposes. Nowadays, ECC muscle actions can be generated using various exercise modalities that target small or large muscle masses with minimal or no muscle damage or pain. The most interesting feature of ECC muscle actions is to combine high muscle force with a low energy cost (typically 4- to 5-times lower than concentric muscle work) when measured during leg cycle ergometry at a similar mechanical power output. Therefore, if caution is taken to minimize the occurrence of muscle damage, ECC muscle exercise can be proposed not only to athletes and healthy subjects, but also to individuals with moderately to severely limited exercise capacity, with the ultimate goal being to improve their functional capacity and quality of life. The first part of this review article describes the available exercise modalities to generate ECC muscle work, including strength and conditioning exercises using the body's weight and/or additional external loads, classical isotonic or isokinetic exercises and, in addition, the oldest and newest specifically designed ECC ergometers. The second part highlights the physiological and mechanical properties of ECC muscle actions, such as the well-known higher muscle force-generating capacity and also the often overlooked specific cardiovascular and metabolic responses. This point is particularly emphasized by comparing ECC and concentric muscle work performed at similar mechanical (i.e., cycling mechanical power) or metabolic power (i.e., oxygen uptake, VO2). In particular, at a similar mechanical power, ECC muscle work induces lower metabolic and cardiovascular responses than concentric muscle work. However, when both exercise modes are performed at a similar level of VO2, a greater cardiovascular stress is observed during ECC muscle work. This observation underlines the need of cautious interpretation of the heart rate values for training load management because the same training heart rate actually elicits a lower VO2 in ECC muscle work than in concentric muscle work. The last part of this article reviews the documented applications of ECC exercise training and, when possible, presents information on single-joint movement training and cycling or running training programs, respectively. The available knowledge is then summarized according to the specific training objectives including performance improvement for healthy subjects and athletes, and prevention of and/or rehabilitation after injury. The final part of the article also details the current knowledge on the effects of ECC exercise training in elderly populations and in patients with chronic cardiac, respiratory, metabolic or neurological disease, as well as cancer. In conclusion, ECC exercise is a promising training modality with many different domains of application. However, more research work is needed to better understand how the neuromuscular system adapts to ECC exercise training in order to optimize and better individualize future ECC training strategies.


Assuntos
Exercício Físico/fisiologia , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Humanos , Resistência Física/fisiologia
12.
Fundam Clin Pharmacol ; 24(3): 333-40, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19682081

RESUMO

Impaired skeletal muscle energetic participates in peripheral arterial disease (PAD) patient's morbidity and mortality. Angiotensin converting enzyme inhibition (ACEi), cornerstone for pharmacologic risk factor management in PAD patients, might also be interesting by protecting skeletal muscle energetic. We therefore determined whether chronic ACEi might reduce ischemia-induced mitochondrial respiratory chain dysfunction in the frequent setting of hindlimb ischemia-reperfusion. Ischemic legs of rats submitted to 5 h ischemia induced by a rubber band tourniquet applied on the root of the hindlimb followed by reperfusion without (IR, n = 11) or after ACEi (n = 14; captopril 40 mg/kg per day during 28 days before surgery) were studied and compared to that of sham-operated animals (n = 11). The effect of ACEi on the non-ischemic contralateral leg was also determined in the ACEi group. Maximal oxidative capacities (V(max)) and complexes I, II and IV activities of the mitochondrial respiratory chain of the gastrocnemius muscle were determined using glutamate-malate, succinate and TMPD-ascorbate substrates. Arterial blood pressure was significantly decreased after ACEi (124 +/- 2.8 vs. 108 +/- 4.19 mmHg; P = 0.01). Ischemia-reperfusion reduced V(max) (4.4 +/- 0.4 vs. 8.7 +/- 0.5 micromol O2/min/g dry weight, -49%, P < 0.001), affecting mitochondrial complexes I, II and IV activities. ACEi failed to modulate ischemia-induced dysfunction (V(max) 5.1 +/- 0.7 micromol O2/min/g dry weight) or the non-ischemic contralateral muscle respiratory rate. Ischemia-reperfusion significantly impaired the mitochondrial respiratory chain I, II and IV complexes of skeletal muscle. Pharmacologic pre-treatment with ACEi did not prevent or increase such alterations. Further studies might be useful to improve the pharmacologic conditioning of PAD patients needing arterial revascularization.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/enzimologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Inibição Neural/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismo por Reperfusão/enzimologia , Animais , Esquema de Medicação , Transporte de Elétrons/efeitos dos fármacos , Transporte de Elétrons/fisiologia , Membro Posterior/irrigação sanguínea , Membro Posterior/efeitos dos fármacos , Membro Posterior/enzimologia , Masculino , Mitocôndrias Musculares/patologia , Músculo Esquelético/irrigação sanguínea , Inibição Neural/fisiologia , Ratos , Ratos Wistar , Recuperação de Função Fisiológica/fisiologia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Fatores de Tempo , Resultado do Tratamento
13.
J Appl Physiol (1985) ; 100(4): 1249-57, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16339351

RESUMO

This study investigates whether adaptations of mitochondrial function accompany the improvement of endurance performance capacity observed in well-trained athletes after an intermittent hypoxic training program. Fifteen endurance-trained athletes performed two weekly training sessions on treadmill at the velocity associated with the second ventilatory threshold (VT2) with inspired O2 fraction = 14.5% [hypoxic group (Hyp), n = 8] or with inspired O2 fraction = 21% [normoxic group (Nor), n = 7], integrated into their usual training, for 6 wk. Before and after training, oxygen uptake (VO2) and speed at VT2, maximal VO2 (VO2 max), and time to exhaustion at velocity of VO2 max (minimal speed associated with VO2 max) were measured, and muscle biopsies of vastus lateralis were harvested. Muscle oxidative capacities and sensitivity of mitochondrial respiration to ADP (Km) were evaluated on permeabilized muscle fibers. Time to exhaustion, VO2 at VT2, and VO2 max were significantly improved in Hyp (+42, +8, and +5%, respectively) but not in Nor. No increase in muscle oxidative capacity was obtained with either training protocol. However, mitochondrial regulation shifted to a more oxidative profile in Hyp only as shown by the increased Km for ADP (Nor: before 476 +/- 63, after 524 +/- 62 microM, not significant; Hyp: before 441 +/- 59, after 694 +/- 51 microM, P < 0.05). Thus including hypoxia sessions into the usual training of athletes qualitatively ameliorates mitochondrial function by increasing the respiratory control by creatine, providing a tighter integration between ATP demand and supply.


Assuntos
Tolerância ao Exercício/fisiologia , Hipóxia/metabolismo , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Corrida , Adaptação Fisiológica , Difosfato de Adenosina/metabolismo , Adulto , Metabolismo Energético , Humanos , Hipóxia/fisiopatologia , Cinética , Masculino , Consumo de Oxigênio , Ventilação Pulmonar , Medicina Esportiva
14.
J Appl Physiol (1985) ; 93(2): 569-75, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12133866

RESUMO

We investigated the hemodynamic, renal, and hormonal responses to neutral endopeptidase (NEP) inhibition during a 6-h, double-blind, randomized, placebo-controlled study in seven chronic, stable heart transplant patients. Baseline characteristics were similar during both experiments, and no significant changes were observed after placebo. NEP inhibition increased circulating endothelin-1 (from 2.01 +/- 0.1 to 2.90 +/- 0.2 pmol/l; P < 0.01), atrial natriuretic peptide (ANP; from 21.5 +/- 2.7 to 29.6 +/- 3.7 pmol/l; P < 0.01), and the ANP second messenger cGMP. Noteworthy, systemic blood pressure did not increase. Renal plasma flow and glomerular filtration rate remained unmodified after NEP inhibition. Filtration fraction (33 +/- 13%), diuresis (196 +/- 62%), and natriuresis (315 +/- 105%) increased significantly in relation to ANP and cGMP. A strong inverse relationship was observed between excreted cGMP and sodium reabsorption (r = -0.71, P < 0.0001). Thus, despite significantly increasing endothelin-1, NEP inhibition did not adversely influence systemic or renal hemodynamics in transplant patients. ANP, possibly through a tubular action, enhances the natriuresis observed after NEP inhibition.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Transplante de Coração , Neprilisina/antagonistas & inibidores , Inibidores de Proteases/administração & dosagem , Tiorfano/análogos & derivados , Tiorfano/administração & dosagem , Adulto , Fator Natriurético Atrial/sangue , GMP Cíclico/sangue , GMP Cíclico/urina , Ciclosporina/sangue , Método Duplo-Cego , Endotelina-1/sangue , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Imunossupressores/sangue , Masculino , Pessoa de Meia-Idade , Natriurese/efeitos dos fármacos , Circulação Renal/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos
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