Restricted postexercise pulmonary diffusion capacity and central blood volume depletion.
Pulmonary diffusion capacity for carbon monoxide (DLCO), regional electrical impedance (Z0), and the distribution of technetium-99m-labeled erythrocytes together with concentration of plasma atrial natriuretic peptide (ANP) were determined before and after a 6-min "all-out" row in nine oarsmen and in six control subjects. Two and one-half hours after exercise in the upright seated position, DLCO was reduced by 6 (-2 to 21; median and range) %, the thoracic-to-thigh electrical impedance ratio (Z0 thorax/Z0 thigh) rose by 14 (-1 to 29) %, paralleled by a 7 (-3 to 11) % decrease and a 3 (-5 to 12) % increase in the thoracic and thigh blood volume, respectively. These responses were associated with a decrease in the plasma ANP concentration from 15 (13-31) to 12 (9-27) pmol/l (P < 0.05). Similarly, in the supine position, Z0 thorax/Z0 thigh increased by 10 (-5 to 28) % when DLCO was reduced 12 (6-26) % (P < 0.05), whereas DLCO remained stable in the control group. The increase in Z0 thorax/Z0 thigh and the corresponding redistribution of the blood volume in both body positions show that approximately one-half of the postexercise reduction of DLCO is explained by a decrease in the pulmonary blood volume. The role of a reduced postexercise central blood volume is underscored by the lower plasma ANP, which aids in upregulating the blood volume after exercise in athletes.
Hanel
B
B
Department of Clinical Physiology, Copenhagen Muscle Research Center, Rigshospitalet, DK-2100 Copenhagen, Denmark.
Teunissen
I
I
Rabol
A
A
Warberg
J
J
Secher
N H
NH
D000328:Adult; D000375:Aging / Q000502:physiology; D009320:Atrial Natriuretic Factor / Q000097:blood; D001810:Blood Volume / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D002248:Carbon Monoxide / Q000097:blood; D017097:Electric Impedance; D015444:Exercise / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D013670:Sodium Pertechnetate Tc 99m / Q000097:blood
D006728:Hormones; D002248:Carbon Monoxide; D009320:Atrial Natriuretic Factor; D013670:Sodium Pertechnetate Tc 99m