title: Arm blood flow at rest and during arm exercise.
abstract: To test the applicability of a dye-dilution method to quantitate total arm blood flow at rest and during arm exercise, indocyanine green was infused at a constant rate into the brachial artery. Eight subjects performed continuous 30-min arm exercises with an increase in intensity every 10 min (30, 60, and 90 W). The loads corresponded to 29 +/- 1, 48 +/- 2, and 78 +/- 4% (means +/- SE) of the maximal O2 uptake (VO2max 2.13 +/- 0.08 l/min) during arm exercise. VO2max during arm exercise was 61 +/- 1.7% of that during leg exercise. The dye concentration was analyzed in blood samples from three arm veins, two ipsi- and one contralateral, at shoulder level. Corresponding dye concentrations in both ipsilateral veins and a stable concentration difference between ipsi- and contralateral veins were achieved. Total arm blood flow was calculated to be 0.21 +/- 0.04 l/min at rest and 2.43 +/- 0.14 l/min at 90 W. Arm O2 uptake rose from 9 +/- 2 to 323 +/- 21 ml/min. Arm blood flow and O2 uptake each correlated linearly with both work load (r = 0.98) and pulmonary O2 uptake (r greater than or equal to 0.98). Mechanical efficiency for the arm and body was 34-44 and 16-19%, respectively. We conclude that arm blood flow can be determined by continuous infusion of indocyanine green.
authors.affiliation: Department of Clinical Physiology, Södersjukhuset, Stockholm, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Ahlborg
authors.forename: M
authors.initials: M
authors.lastname: Jensen-Urstad
mesh_terms: D000328:Adult; D001132:Arm / Q000098:blood supply*; D001783:Blood Flow Velocity / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012119:Respiration / Q000502:physiology