Concentrations of DA in TYR solutions as a function of duration of storage at 4 °C (●) and −70 °C (○; A), and increment in arterial plasma DA concentration as a function of infusate DA concentration in humans undergoing intravenous infusion of TYR (B).
(A), equation for the line: y = 38(0.31x); r = 0.99. (B), ○, patients with chronic orthostatic intolerance; □, patients with chronic autonomic failure; △, patients status post bilateral thoracic sympathectomies for hyperhidrosis; ◇, healthy volunteer.