1. To determine the effect of a medium dose glucocorticoid/long-acting beta-agonist preparation (250 μg fluticasone plus 50 μg salmeterol) administered for 3 weeks on inhaled albuterol and sub-lingual NTG induced vasodilation in the bronchial artery, as assessed by ΔQaw in stable glucocorticoid-naïve COPD patients, and to re-assess the responses after a 3 week glucocorticoid/long-acting beta-agonist washout period.