L-NAME and L-arginine differentially ameliorate cigarette smoke-induced emphysema in mice.

Nitric oxide (NO) represents one of the most important intra- and extracellular mediators and takes part in both biologic and pathologic processes. This study aimed to verify the treatment with an NO inhibitor and an NO substrate in pulmonary emphysema induced by cigarette smoke (CS) in a murine model. We compared N-acetylcysteine (NAC), a precursor of glutathione, to G-nitro-L-arginine-methyl ester or L-NAME (LN), which is an NO inhibitor, and to l-arginine (LA), which is a substrate for NO formation. Mice were divided into several groups: control, CS, CS + LN, CS + LA, and CS + NAC. Control and CS groups were treated daily with a vehicle, while CS + LN, CS + LA, and CS + NAC groups were treated daily with LN (60 mg/kg), LA (120 mg/kg) and NAC (200 mg/kg), respectively. The bronchoalveolar lavage was analyzed and the lungs were removed for histological and biochemical analysis. CS increases neutrophil number. Neutrophil number was lowest in CS + LN, followed by CS + LA. The lungs of CS + LN, CS + LA and CS + NAC mice were protected compared to the lungs of CS mice, but not equal to the quality of lungs in control mice. The CS group also exhibited increased oxidative stress, which was also present in the CS + LN group and to a lesser extent in the CS + LA group. Tissue inhibitor of metalloproteinase 1 and 2 increased in the CS + LN group and to a lesser extent in the CS + LA group relative to the control group. These results suggest that LN and LA treatment protected the mouse lung from CS. However, NAC treatment was more than LN and LA. We suggest that the protection conferred by LN treatment requires a balance between proteases and antiproteases, and that protection conferred by LA treatment involves the balance between oxidants and antioxidants.

Correlação entre a pressão expiratória máxima (pemáx) e pico de fluxo expiratório máximo (pfe) em indivíduos saudáveis / Correlation between maximal expiratory pressure (mpe) and maximal expiratory flow peak (mefp) in healthy individuals

Introdução: A prova de função pulmonar é um recurso que tem colaborado com a validação científica da fisioterapia respiratória. Ela é capaz de estimar, entre outras variáveis, as alterações dos volumes e capacidades pulmonares, e/ ou as alterações da força dos músculos respiratórios. A mensuração da força é realizada através do manovacuômetro, no qual se obtém a pressão expiratória máxima (PEmáx.). Outra forma de avaliar a função pulmonar é a medida do pico de fluxo expiratório (PFE). Objetivos: Investigar a correlação entre a PEmáx. e PFE, em indivíduos saudáveis. Métodos: O estudo foi realizado na Universidade Severino Sombra. Oitenta e um voluntários de ambos os sexos, 55 do sexo feminino (22,69 ± 0,41 anos), e 26 do sexo masculino (23,11 ± 3,51 anos) participaram deste estudo. Um questionário respiratório foi aplicado para investigar parâmetros clínicos. Todos os indivíduos realizaram exame de manovacuometria e medidor de PFE, em posição ortostática. Os dados foram expressos como média ± erro padrão da média. Resultados: Uma correlação positiva foi encontrada entre a PEmáx. e PFE (r = 0,43; r2 = 0,18, p <0,001). Foi estimada a equação de regressão linear (PFE = 2,93 + 148,07 x PEmáx.), e os valores normais estimados foram apresentados em uma tabela. Conclusões: Este estudo mostra a influência da força dos músculos expiratórios no PFE em vias aéreas, e sugeriu uma equação para estimar a função ventilatória normal, na prática clínica.

Introduction: The pulmonary function is a feature that has collaborated with the scientific validation of respiratory therapy. It is able to estimate, among other variables, changes in lung volumes and capacities, and/or changes in respiratory muscle strength. The measurement of force is obtained by the manometer, through which one can obtain the maximum expiratory pressure (MEP). Another way to assess lung function is by the measurement of expiratory flow peak (EFP). Objectives: To investigate the correlation between MEP and EFP in healthy individuals (patients). Methods: This study was developed at the Severino Sombra University. Eighty-one volunteers of both sexes, 55 females (22.69 ± 0.41 years) and 26 males (23.11 ± 3.51 years) participated in this study. A respiratory questionnaire was applied to investigate clinical parameters. All individuals underwent manometer examination and flow peak measurement, in the standing position. Data were expressed as mean ± standard error of mean. Results: A positive correlation was found between MEP and EFP (r = 0.43, r2 = 0.18, p <0.001). The linear regression equation was estimated (PEF = 148.07 + 2.93 x MEP) and normal values were presented in a table. Conclusions: This study shows the influence of expiratory muscle strength in EFP in the airways, and suggested an equation to estimate the normal ventilating function in clinical practice.