Ventilation and Pulmonary Endothelium Toxicities of E-cigarettes: A Randomized Crossover Pilot Study

The study e-cigarette exposure will be 10 puffs with 30-second inter-puff intervals, as directly observed by a trained research assistant, using a standardized e-cigarette. Cartomizers, batteries, and e-liquids will be obtained from commercial suppliers. The e-cigarette device will be loaded with 1 mL of flavorless e-liquid with a ratio of PG to vegetable glycerin of 70:30 and 1.8 mg/dL of nicotine.

"The unexposed condition will be breathing from the study e-cigarette (10 puffs with 30-second inter-puff intervals) with the battery off."

Hyperpolarized 3-Helium will be used as an experimental contrast agent for the Ventilation MRIs performed twice per participant in both experimental arms. Approximately 250-600 mL of hyperpolarized 3He mixed with 300-750 mL nitrogen will be inhaled through a one-way valve in one inhalation starting approximately at residual volume.

Gadolinium contrast will be injected into the antecubital vein through an 18-20 gauge IV. The type of gadolinium will be 0.03 mmol/kg bodyweight of dotarem (gadoterate meglumine).