The Beta-2 adrenergic receptors (β2ARs) are located on alveolar cells and the pulmonary lymphatics and regulate lung fluid clearance through activation of epithelial sodium channels on the alveolar cells and through the relaxation of the lymphatic vessels. We sought to determine the influence of an inhaled β2-selective agonist on alveolar-capillary conductance (DM) and pulmonary capillary blood volume (Vc) in healthy humans. To determine this, we assessed the diffusing capacity of the lungs for carbon monoxide (DLCO) and nitric oxide before and every 15 minutes for one-hour following the administration of nebulized albuterol (2.5mg, diluted to 3ml) in 28 healthy subjects (age=28±5yrs, ht=171±14cm, wt=75±17kg, BMI=26±8kg/m2, values are mean±SD). Cardiac output (Q, determined via acetylene wash-in), heart rate (HR), stroke volume (SV), systemic vascular resistance (SVR), blood pressure (BP), and oxygen saturation (SaO2) were also assessed at baseline and following the administration of albuterol. Albuterol resulted in elevations in HR, Q, and SV as well as a drop in SVR (% change from baseline, HR=4±11, 4±8, 4±8, and 4±8%; Q=15±17, 12±17, 9±19, and 4±17%; SV= 24±32, 16±27, 11±28, and 14±23%; and SVR= −15±12, −12±16, −7±20, and −4±17, at 15, 30, 45, and 60 minutes post-albuterol, respectively, P-ANOVA<0.05), but no change in BP. There was no change in DLCO, a decrease in Vc and an increase in DM when assessed alone or when corrected for Vc (%change from baseline, Vc=5±37, −5±30, −12±35, and −20±26%, DM= 0±18, 1±18, 6±22, and 5±19%; DM/Vc=10±44, 17±48, 47±70, and 48±70%, at 15, 30, 45, and 60 minutes post-nebulization, respectively, p<0.05). These data suggest that the administration of albuterol improves alveolar-capillary conductance in healthy humans, despite a small decrease in pulmonary capillary blood volume.