Malvin G M, Hlastala M P
Respir Physiol. 1986 Jul;65(1):99-111. doi: 10.1016/0034-5687(86)90009-5.
The effects of environmental PO2 and PCO2 on cutaneous blood flow and gas exchange were investigated in the frog, Rana pipiens. Halothane (Ha) anesthetized frogs were equilibrated with 9.5% Freon-22 (Fr), 1.1% Ha and air while placed in a box. A gas mixture, initially free of Ha and Fr, was drawn through a small test chamber placed on the abdomen. The excretion of Fr, Ha and CO2 into the sample chamber was analyzed by a mass spectrometer. Under these conditions, changes in Fr or Ha excretion into the sample chamber reflected local changes in skin perfusion. Raising sample chamber [O2] produced concentration-dependent increases in the excretion of all gases measured. Lowering chamber [O2] reduced gas excretion. Increasing chamber [CO2] to 5% decreased the excretion of Fr and Ha. Increasing box [O2] to 86.5% while keeping sample chamber [O2] constant at 21% decreased gas excretion into the chamber. Selectively raising box [CO2] to 4.3% increased gas excretion into the chamber. The results indicate that regional cutaneous blood flow and gas exchange is a direct function of the [O2] directly above that portion of skin, and inversely related to the [O2] over adjacent skin. This regional perfusion-O2 matching may act to optimize total cutaneous gas exchange in the frog. In addition, CO2 may be an important regulator of cutaneous blood flow distribution.
研究了环境中氧分压（PO2）和二氧化碳分压（PCO2）对北美豹蛙皮肤血流和气体交换的影响。将氟烷（Ha）麻醉的青蛙置于箱中，使其与9.5%的氟利昂 - 22（Fr）、1.1%的Ha和空气达到平衡。一种最初不含Ha和Fr的混合气体通过放置在腹部的小型测试室抽取。通过质谱仪分析Fr、Ha和二氧化碳向样品室的排泄情况。在这些条件下，向样品室排泄的Fr或Ha的变化反映了皮肤灌注的局部变化。提高样品室的[O2]会使所测所有气体的排泄量呈浓度依赖性增加。降低样品室的[O2]会减少气体排泄。将样品室的[CO2]增加到5%会减少Fr和Ha的排泄。在保持样品室[O2]恒定在21%的情况下，将箱内[O2]增加到86.5%会减少进入样品室的气体排泄。选择性地将箱内[CO2]提高到4.3%会增加进入样品室的气体排泄。结果表明，局部皮肤血流和气体交换是皮肤上方[O2]的直接函数，并且与相邻皮肤上方的[O2]呈负相关。这种局部灌注与氧的匹配可能有助于优化青蛙的整体皮肤气体交换。此外，二氧化碳可能是皮肤血流分布的重要调节因子。
