Jackson D C
Respir Physiol. 1978 Apr;33(1):103-14. doi: 10.1016/0034-5687(78)90089-0.
The respiratory control systems of the predominantly lung-breathing turtle. Pseudemys scripta, and the bimodal breathing frog, Rana catesbeiana, are compared. At constant temperature, control is effected in both species primarily by pulmonary ventilation, and appears to be similar in basic organization to the mammalian system. The skin CO2 exchange of the frog is largely passive and apparently under little adaptive control. CO2 exchange at different temperature is analyzed by means of the conductance equations: convective conductance [MCO2 = (VA/RT).pACO2] for lung exchange, and diffusive conductance (MCO2 = GCO2.transcutaneous deltaPCO2) for skin exchange. Predictions of conductance values, based on data for PaCO2 and MO2, agree well with measured values of both the turtle's ventilation and the frog's skin CO2 conductance at different temperatures. In each case the conductances increase only moderately, if at all, with temperature, a result that can be attributed to the similar Q10 values of PaCO2 and MO2. Because the conductances exhibit this blunted temperature dependence, both lung and skin breathers are provided with the respiratory effector mechanisms necessary to regulate PaCO2 and pHa at their characteristic values over the ectothermic temperature range.
对主要用肺呼吸的伪彩龟（Pseudemys scripta）和具有双峰呼吸的牛蛙（Rana catesbeiana）的呼吸控制系统进行了比较。在恒温条件下，这两个物种的呼吸控制主要通过肺通气来实现，其基本组织似乎与哺乳动物系统相似。青蛙的皮肤二氧化碳交换在很大程度上是被动的，显然几乎没有适应性控制。通过传导方程分析了不同温度下的二氧化碳交换：肺交换的对流传导（MCO2 = (VA/RT).pACO2）和皮肤交换的扩散传导（MCO2 = GCO2.transcutaneous deltaPCO2）。根据动脉血二氧化碳分压（PaCO2）和氧耗量（MO2）数据预测的传导值，与不同温度下乌龟的通气量和青蛙皮肤二氧化碳传导的测量值非常吻合。在每种情况下，传导仅适度增加（如果有的话），这一结果可归因于PaCO2和MO2相似的温度系数（Q10）值。由于传导表现出这种减弱的温度依赖性，肺呼吸者和皮肤呼吸者都具备在变温动物温度范围内将PaCO2和动脉血pH值调节到其特征值所需的呼吸效应机制。
