Feder M E, Full R J, Piiper J
Abteilung Physiologie, Max-Planck-Institut für experimentelle Medizin, Göttingen, F.R.G.
Respir Physiol. 1988 May;72(2):229-40. doi: 10.1016/0034-5687(88)90009-6.
To quantify diffusion limitation in cutaneous gas exchange, the elimination of two inert gases of different diffusivity, Freon 22 (CHC1F2) and acetylene (C2H2), was measured simultaneously in exclusively skin-breathing lungless salamanders, Desmognathus quadramaculatus. In resting salamanders, elimination of both gases could be described as the sum of three exponential terms. For both the medium and the slow exponential component, the ratio of the respective rate constants (k) for acetylene and Freon averaged 1.77. This value is between the values expected for perfusion limitation (1.00) and diffusion limitation (1.94), indicating combined diffusion and perfusion limitation. In salamanders stimulated to run on a treadmill, the elimination rates and the rate constants increased more for Freon than for acetylene. During spontaneous activity, the increase in elimination of Freon was larger than that of acetylene. These findings suggest an increase in the diffusing capacity of the skin during exercise. Thus the diffusing capacity of salamander skin for gases appears to be variable and to be adjusted to meet the increased O2 requirement during exercise.
为了量化皮肤气体交换中的扩散限制，在完全通过皮肤呼吸的无肺蝾螈四斑钝口螈（Desmognathus quadramaculatus）中，同时测量了两种不同扩散率的惰性气体——氟利昂22（CHC1F2）和乙炔（C2H2）的清除情况。在静止的蝾螈中，两种气体的清除都可以描述为三个指数项的总和。对于中等和缓慢的指数成分，乙炔和氟利昂各自的速率常数（k）之比平均为1.77。该值介于灌注限制预期值（1.00）和扩散限制预期值（1.94）之间，表明存在扩散和灌注的联合限制。在被刺激在跑步机上奔跑的蝾螈中，氟利昂的清除率和速率常数的增加幅度大于乙炔。在自发活动期间，氟利昂清除的增加幅度大于乙炔。这些发现表明运动期间皮肤的扩散能力增加。因此，蝾螈皮肤对气体的扩散能力似乎是可变的，并会进行调整以满足运动期间增加的氧气需求。
