Eicosapentaenoic acid is more effective than docosahexaenoic acid in inhibiting proinflammatory mediator production and transcription from LPS-induced human asthmatic alveolar macrophage cells

Background & aims: The purpose of the study was to determine which of the active constituents of fish oil, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), is most effective in suppressing proinflammatory mediator generation and cytokine expression from LPS-stimulated human asthmatic alveolar macrophages (AMΦ). Methods: The AMΦ were obtained from twenty-one asthmatic adults using fiberoptic bronchoscopy. Cells were pretreated with DMEM, pure EPA, an EPA-rich media (45% EPA/10% DHA), pure DHA, a DHArich media (10% EPA/50% DHA) or Lipovenos® (n-6 PUFA), and then exposed to Dulbecco’s Modified Eagle’s Medium (DMEM) (-) or LPS (+). Supernatants were analyzed for leukotriene (LT)B4, prostaglandin (PG)D2, tumor necrosis factor (TNF)-α and interleukin (IL)-1β production. Detection of TNF-α and IL-1β mRNA expression levels was quantified by reverse transcriptase polymerase chain reaction. Results: 120 μM pure EPA and EPA-rich media significantly (p < 0.05) suppressed TNF-a and IL-1b mRNA expression and the production of LTB4, PGD2 and TNF-a and IL-1b in LPS-stimulated primary AMφ cells obtained from asthmatic patients to a much greater extent than 120 mM pure DHA and DHA-rich media respectively. Conclusions: This study has shown for the first time that EPA is a more potent inhibitor than DHA of inflammatory responses in human asthmatic AMΦ cells

Pulmonary adaptations to swim and inspiratory muscle training

Because the anomalous respiratory characteristics of competitive swimmers have been suggested to be due to inspiratory muscle work, the respiratory muscle and pulmonary function of 30 competitively trained swimmers was assessed at the beginning and end of an intensive 12-week swim training (ST) program. Swimmers (n = 10) combined ST with either inspiratory muscle training (IMT) set at 80% sustained maximal inspiratory pressure (SMIP) with progressively increased work–rest ratios until task failure for 3-days per week (ST + IMT) or ST with sham-IMT (ST + SHAM-IMT, n = 10), or acted as controls (ST only, ST, n = 10). Measures of respiratory and pulmonary function were assessed at the beginning and end of the 12 week study period. There were no significant differences (P > 0.05) in respiratory and pulmonary function between groups (ST + IMT, ST + SHAM-IMT and ST) at baseline and at the end of the 12 week study period. However, within all groups significant increases (P < 0.05) were observed in a number of respiratory and pulmonary function variables at the end of the 12 week study, such as maximal inspiratory and expiratory pressure, inspiratory power output, forced vital capacity, forced expiratory and inspiratory volume in 1-s, total lung capacity and diffusion capacity of the lung. This study has demonstrated that there are no appreciable differences in terms of respiratory changes between elite swimmers undergoing a competitive ST program and those undergoing respiratory muscle training using the flow-resistive IMT device employed in the present study; as yet, the causal mechanisms involved are undefined

Effect of flow-resistive inspiratory loading on pulmonary and respiratory muscle function in sub-elite swimmers

© 2014 Edizioni Minerva Medica. BACKGROUND: The aim of this study was to evaluate the effects of a 12-week swim training and inspiratory muscle training program on respiratory muscle and pulmonary function in competitively trained sub-elite swimmers. METHODS: A double-blind, parallel-group experimental design was employed to compare the effects of swim training alone, swim training with sham-inspiratory muscle training, and swim training with true inspiratory muscle training. Twenty-four competitively trained sub-elite swimmers combined swim training with either flow-resistive inspiratory muscle training set at 80% sustained maximal inspiratory pressure with progressively increased work-rest ratios until task failure for 3 days/week (swim training with inspiratory muscle training, N.=8), or swim training with sham-inspiratory muscle training (N.=8), or acted as controls (swim training only, N.=8). Measures of pulmonary and respiratory muscle function were assessed at the beginning and end of the 12-week study period. RESULTS: At baseline, there were no significant differences (P > 0.05) in respiratory muscle and pulmonary function between groups. Following the 12-week training period, the swim training with inspiratory muscle training group demonstrated improvements in maximal inspiratory pressure, sustained maximal inspiratory pressure, maximal inspiratory muscle power output, inspiratory muscle work capacity, inspiratory time of contraction, time to fatigue, maximal voluntary ventilation in 12 seconds, and forced inspiratory volume in 1-second (P 0.05). CONCLUSIONS: Inspiratory muscle training in conjunction with swim training improves respiratory muscle function in sub-elite swimmers when compared to swim training only

Comparative effects of caffeine and albuterol on the bronchoconstrictor response to exercise in asthmatic athletes

The main aim of this study was to evaluate the comparative and additive effects of caffeine and albuterol (short-acting beta (2)-agonist) on the severity of EIB. Ten asthmatic subjects with EIB (exercise-induced bronchoconstriction) participated in a randomized, double-blind, double-dummy crossover study. One hour before an exercise challenge, each subject was given 0, 3, 6, or 9 mg/kg of caffeine or placebo mixed in a flavored sugar drink. Fifteen minutes before the exercise bout, an inhaler containing either albuterol (180 microg) or placebo was administered to each subject. Pulmonary function tests were conducted pre- and post-exercise. Caffeine at a dose of 6 and 9 mg/kg significantly reduced (p0.05) in the post-exercise % fall in FEV (1) between albuterol ( PLUS CAFFEINE PLACEBO) (-4.0+/-5.2%) and the 9 mg/kg dose of caffeine (-6.8+/-6.5%). Interestingly, there was no significant difference (p>0.05) in the post-exercise % fall in FEV (1) between albuterol ( PLUS CAFFEINE PLACEBO) (-4.0+/-5.2%) and albuterol with 3, 6 or 9 mg/kg of caffeine (-4.4+/-3.8, -6.8+/-5.6, -4.4+/-6.0% respectively). Similar changes were observed for the post-exercise % fall in FVC, FEF (25-75%) and PEF. These data indicate that moderate (6 mg/kg) to high doses (9 mg/kg) of caffeine provide a significant protective effect against EIB. It is feasible that the negative effects of daily use of short-acting beta (2)-agonists by asthmatic athletes could be reduced simply by increasing caffeine consumption prior to exercise