Mackenzie J A, Jackson D C
Respir Physiol. 1978 Mar;32(3):313-23. doi: 10.1016/0034-5687(78)90119-6.
Cutaneous and pulmonary CO2 loss were measured simultaneously in bullfrogs, Rana catesbeiana, at either 10, 20 or 30 degrees C. Arterial blood samples were taken in each experiment and analysed for [H+] and total plasma [CO2]. These values were used to calculate Pa(CO2) by means of the Henderson-Hasselbalch equation. Both [H+] and Pa(CO2) increased with temperature as previously observed. Skin CO2 loss was measured using a titration method. (At 30 degrees C it was necessary to add calcium hypochlorite (5-9 ppm) to block bacterial growth and respiration). Skin CO2 loss rose with temperature but the mean fraction of the total CO2 lost by this route decreased from about 50% at 10 degrees C to less than a third at 30 degrees C. At each temperature, over 90% of an incremental increase in total CO2 loss was excreted via the lungs while skin loss was relatively constant over a wide range of total loss values. The increase in skin CO2 loss with temperature corresponded to a proportional increase in the estimated transcutaneous P(CO2) difference. (This difference was assumed to equal Pa(CO2) minus ambient P(CO2.) Consequently, the skin CO2 conductance (skin CO2 loss/transcutaneous P(CO2) was not significantly influenced by temperature. This apparent temperature independence of skin CO2 conductance may be important for acid-base regulation of skin breathers in response to temperature change.
在10℃、20℃或30℃的条件下，同时测量牛蛙（美国牛蛙，Rana catesbeiana）的皮肤和肺部二氧化碳损失。每次实验均采集动脉血样，并分析其中的[H⁺]和血浆总[CO₂]。利用亨德森 - 哈塞尔巴尔赫方程，通过这些值计算动脉血二氧化碳分压（Pa(CO₂)）。如先前观察到的那样，[H⁺]和Pa(CO₂)均随温度升高而增加。皮肤二氧化碳损失采用滴定法测量。（在30℃时，有必要添加次氯酸钙（5 - 9 ppm）以抑制细菌生长和呼吸作用）。皮肤二氧化碳损失随温度升高而增加，但通过该途径损失的二氧化碳占总二氧化碳损失的平均比例从10℃时的约50%降至30℃时的不到三分之一。在每个温度下，总二氧化碳损失增量的90%以上是通过肺部排出的，而在总损失值的广泛范围内，皮肤损失相对恒定。皮肤二氧化碳损失随温度的增加与估计的经皮二氧化碳分压差（P(CO₂)）的成比例增加相对应。（假设该差值等于Pa(CO₂)减去环境二氧化碳分压）。因此，皮肤二氧化碳传导率（皮肤二氧化碳损失/经皮二氧化碳分压差）不受温度的显著影响。皮肤二氧化碳传导率这种明显的温度独立性对于皮肤呼吸动物应对温度变化的酸碱调节可能很重要。
