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SummaryEndothelin-1 (ET-1) has been implicated in the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD) for establishing an inflammatory loop in the respiratory mucosa that could become independent from the initial irritant factor. Common causes of COPD exacerbations are associated with elevated ET-1 sputum concentrations. Genetic variants of the ET-1 gene, that lead to elevated ET-1 peptide levels, have not been investigated in COPD.We performed a case control, genetic study to assess possible associations of two polymorphisms of the ET-1 gene, an adenine insertion (+134 insA/delA) and a guanine to thymine transversion (G198T) with the COPD phenotype and disease severity.The genotypes of 209 subjects, 107 COPD smokers (patients) and 102 non-COPD smokers (controls) were examined. Statistical analysis revealed that the 3A/4A and 4A/4A genotypes were more common (P

Background: Endothelin-1 (ET-1) has been implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). The ET-1 levels are elevated during exacerbations of asthma and COPD in bronchoalveolar lavage, serum, and sputum and fails with treatment of the exacerbations. Hypoxemia stimulates ET-1 secretion. Objective: The aim of this study was to examine the serum ET-1 levels in stable asthmatic and COPD patients. Materials and methods: We examined 48 COPD and 26 asthmatic patients and 34 normal subjects. We collected arterial samples to measure baseline ET-1 levels in all patients and in the control group, during the day. All the patients underwent formal polysomnography (EEG, ECG, airflow, respiratory muscle movement, oximeter) to detect the presence of nocturnal, nonapneic, and oxyhemoglobin desaturation. Twelve of the COPD patients and six of the asthmatic patients were disqualified because of inadequate sleep or sleep apnea syndrome. Nineteen of the COPD patients desaturated below a baseline sleep saturation of 90% for 5min or more, reaching a nadir saturation of at least 85%. We collected arterial samples to measure ET-1 levels, 5min after the first period of desaturation in each of the 19 desaturators COPD patients. None of the 20 asthmatic patients exhibited oxyhemoglobin desaturation during sleep. Results: Baseline arterial ET-1 levels during the day were significantly higher in “desaturators” COPD patients (2.08±0.28pg/ml) compared to “non-desaturators” COPD patients (1.38±0.16pg/ml) (P

Endothelins are a family of peptide mediators that have a number of biological properties, including the ability to act as bronchoconstrictors and vasoconstrictors of isolated airways and vessels. Endothelin-1 (ET-1) is the more potent peptide compared with the other two peptides of the family. To examine a possible involvement of ET- 1 in the pathogenesis of asthma, we measured arterial ET-1 levels in 11 patients with atopic asthma during attack and during remission, and in 11 healthy control subjects. We also performed fiberoptic bonchoscopy and bronchoalveolar lavage (BAL) to measure ET-1 levels in the 11 asthmatic patients during remission, and in the 11 healthy control subjects. ET-1 concentrations in arterial blood and in BAL were measured by a radioimmunoassay method. Arterial ET-1 levels were very significantly higher in asthma attack (3.67 +/- 0.51 pg ml(-1)) and in asthma remission (2.65 +/- 10.62 pg ml(-1)) compared with those of the healthy controls (1.37 +/- 0.14 pg ml(-1)) (P < 0.001). Arterial ET-1 levels were also very significantly higher during asthma attack compared with those in asthma remission (P < 0.001). BAL ET-1 levels were significantly higher in asthma remission (0.73 +/- 0.53 pmol g(-1)) compared with those of the healthy controls (0.16 +/- 0.02 pmol g(-1)) (P < 0.05). No correlation was observed between arterial and BAL ET-1 levels, PaO2 and peak expiratory flow rate (PEFR). These data are consistent with the hypothesis that ET-1 contributes to the pathophysiology of asthma. However, it is likely that the true importance of this vasoconstrictor peptide will only be revealed by pharmacological studies with specific receptor antagonists.

Summary Purpose : The purpose of this study was to examine exercise tolerance in patients with COPD from measurements of resting pulmonary function parameters. Methods : A total of 57 COPD patients were administered the pulmonary function test (PFT) and cardiopulmonary exercise test. The results were analyzed and essentially linear relationships emerged when each subject's V O 2 peak was plotted against his individual PFT parameters. Those significant contributors were then introduced in a stepwise multiple regression analysis to determine the best predictor of the V O 2 peak. Results : Stepwise multiple regressions in variables revealed that peak oxygen consumption ( V O 2 peak) was predicted best by the following equation: V O 2 peak=(maximum voluntary ventilation×0.024)+(forced mid-expiratory flow×0.47)+(body surface area×0.988)−0.913 ( r = 0.90 ; r 2 = 0.81 SE=0.29L/min). Conclusion : We conclude that exercise capacity was predicted from measurements of resting pulmonary function parameters with excellent accuracy in the COPD patient.