In the present proposal the investigators wish to assess the effect of a single session with the device known as Exer-Rest® which applies Whole Body Periodic Acceleration (WBPA) on baseline airway blood flow (Qaw) and in Qaw variation, in current smokers, glucocorticoid-naïve asthmatics, and age-matched healthy never-smokers, with the expectation that the treatment will transiently increase the Qaw, and to a greater extent in the current smokers and patients with asthma who have endothelial dysfunction.

Endothelial shear stress activates nitric oxide synthase (NOS), leading to endothelium-dependent vasodilation. This can be accomplished through exercise or with a device known as Exer-Rest® which applies Whole Body Periodic Acceleration (WBPA) that is also called pGz. WBPA produces systemic vasodilation, by exerting shear stress on the vascular endothelium, activating endothelial NOS and releasing NO in animal models and human subjects. Cigarette smoking is associated with attenuated vascular relaxation responses in the systemic circulation. Patients with asthma also exhibit endothelial dysfunction in the airway. In this study the investigators wish to assess the effect of a single pGz session on baseline Qaw and delta Qaw in current smokers, glucocorticoid-naïve asthmatics, and age-matched healthy never-smokers to test if this treatment will increase the vascular relaxation responses.

Inclusion Criteria:

15 healthy never-smokers, 15 smokers (> than 1 year smoke history) and 15 never-smokers asthmatics; FEV1 > 80% (except for asthmatics subjets)

Exclusion Criteria:

Women of childbearing potential who do not accepted birth control measures; pregnant and breast feeding; cardiovascular disease or use of cardiovascular drugs; respiratory infection during the 4 weeks preceding the study; use of inhaled or systemic glucocorticoids, leukotriene modifiers or theophyllines in asthmatics; FEV1 < 80% on the screening day (excepted for asthmatics subjets)