Pulmonary pharmacology & therapeutics
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Pulm Pharmacol Ther · Jan 2008
Randomized Controlled TrialAcute effects of sildenafil on exercise pulmonary hemodynamics and capacity in patients with COPD.
We investigated in chronic obstructive pulmonary disease (COPD) patients whether a single dose of sildenafil can attenuate the exercise-induced increase in pulmonary artery pressure, thereby allowing augmentation of stroke volume (SV), and improving maximal exercise capacity. ⋯ Regardless of mPpa at rest, sildenafil attenuates the increase in mPpa during submaximal exercise in COPD. This attenuated increase is neither accompanied by enhanced SV and CO, nor by improved maximal exercise capacity.
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Pulm Pharmacol Ther · Jan 2008
Comparative StudyAlpha glucocorticoid receptor expression in different experimental rat models of acute lung injury.
Acute respiratory distress syndrome (ARDS) is a frequent form of hypoxiemic respiratory failure caused by the acute development of diffuse lung inflammation. Dysregulated systemic inflammation with persistent elevation of circulating inflammatory cytokines is the pathogenetic mechanism for pulmonary and extrapulmonary organ dysfunction in patients with ARDS. Glucocorticoids (GCs) have a broad range of inhibitory inflammatory effects, including inhibition of cytokines transcription, cellular activation and growth factor production. They inhibit the inflammatory pathways through two specific intracellular glucocorticoid receptors (GRs), named GR alpha and GR beta. The aim of our study was to evaluate the histologic evidence of inflammatory injury and the GR alpha uptake of resident and inflammatory cells in different experimental models of acute lung injury (ALI). ⋯ These data indicate that ALI is associated with diffuse alveolar damage, up-regulation of the inflammatory response and GR alpha overexpression. Barotrauma is the most effective mechanism inducing acute lung inflammation and GR alpha overexpression.
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The vascular bed in nasal mucosa of different species, including human, is highly vascularized and an extensive sinusoidal network of large capacitance vessels is present deep within the submucosa. When this network of venous sinusoids is engorged with blood, the swollen mucosa reduces the size of the airway lumen and congestion ensues. Nasal vasculature tone is strongly influenced by the sympathetic nervous system and the only drugs approved specifically to relieve vascular nasal obstruction are alpha-adrenoceptor sympathomimetic agents. ⋯ Pharmacological characterization of postjunctional alpha-adrenoceptor in human nasal mucosa. Am J Rhinol 2005;19: 495-502] and displays decongestion without affecting blood pressure. Therefore, an alpha 2-adrenoceptor agonist, by causing constriction in the capacitance vessels of nasal mucosa, can produce nasal decongestion without the effects on blood pressure observed with the standard selective alpha 1-adrenoceptor and non-selective alpha-adrenoceptor sympathomimetic decongestants.
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Pulm Pharmacol Ther · Jan 2008
The effect of pentoxifylline on the pulmonary response to high tidal volume ventilation in rats.
Volume-induced lung injury is associated with lung inflammation. Pentoxifylline inhibits cytokine release and modulates neutrophil function. ⋯ Pentoxifylline was effective in reducing inflammatory lung injury associated with high tidal volume ventilation.
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Pulm Pharmacol Ther · Jan 2008
Randomized Controlled TrialEffects of airway anesthesia on dyspnea and ventilatory response to intravenous injection of adenosine in healthy human subjects.
We have recently shown that intravenous injection of adenosine causes dyspnea and hyperventilation in man, and we suggested that stimulation of vagal C-fibers in the airways and lungs is involved. To test this hypothesis further, the present study was performed in healthy subjects (n=12; age 32.4+/-10.2 yrs, 7 females) to determine if the effect of adenosine could be attenuated by blocking the airway sensory receptors by inhalation of aerosolized lidocaine, a local anesthetic. In each subject, the effects of intravenous injection of adenosine (10mg) on dyspneic sensation, minute ventilation, airway resistance and heart rate were measured after the subject inhaled lidocaine or placebo aerosol on two separate days. ⋯ The intensity of adenosine-induced dyspnea was markedly reduced after the lidocaine pretreatment compared to placebo. In a sharp contrast, the VE and heart rate responses to adenosine were not affected by lidocaine. These results lend further support to our previous studies indicating that the origin of the dyspnogenic action of intravenous adenosine is most likely vagal bronchopulmonary C-fiber sensory nerves.