查看文章

To investigate relationships between pulmonary transit times (PTT) and pulmonary diffusion limitation during exercise, 10 high aerobic capacity athletes (V̇_O2max = 5.15 ± 0.52 l · min⁻¹) who had multiple inert gas elimination analysis evidence suggestive of diffusion disequilibrium were studied at rest and maximal exercise. Diffusing capacity for oxygen (Dl_O2) was calculated from the inert gas data. First pass radionuclide angiography was performed using ^99mTechnecium labeled erythrocytes and whole lung PTT and pulmonary blood volume (PBV) were calculated. PTT decreased from 9.32 ± 1.41 sec at rest, to 2.91 ± 0.30 sec during exercise and was correlated with diffusion limitation suggested by the inert gases (r = -0.58, P < 0.05). PBV increased during exercise to over 25% of whole blood volume and correlated with Dl_O2 (r = 0.82, P < 0.01). These data suggest that diffusion limitation is related to shortened …