Arterial concentration and net exchange across the leg and splanchnic bed of 19 amino acids were determined in healthy, postabsorptive subjects in the resting state and after 10 and 40 min of exercise on a bicycle ergometer at work intensities of 400, 800, and 1200 kg-m/min. Arterio-portal venous differences were measured in five subjects undergoing elective cholecystectomy.
