Heisler N
Respir Physiol. 1978 Apr;33(1):145-60. doi: 10.1016/0034-5687(78)90093-2.
Intracellular/extracellular and extracellular/sea-water bicarbonate exchanges were measured in Larger Spotted Dogfish (Sycliorhinus stellaris) exposed to 10 degrees C temperature step changes in a closed sea-water recirculation system. Changes of the bicarbonate concentration in blood plasma (= extracellular space) and in the recirculating sea-water were monitored for 36 h after the temperature change. Intracellular/extracellular transfer of bicarbonate was computed from bicarbonate changes in the extracellular space and sea-water. When the temperature was changed from 10 to 20 degrees C a signigicant transfer of bicarbonate was observed from the intracellular to the extracellular compartment and from the extracellular compartment to the sea-water. These transfers were reversed when the temperature was lowered from 20 to 10 degrees C. The exchange processes were practically completed after 18 h. The amount of bicarbonate exchanged between intracellular and extracellular compartments and sea-water was larger than predicted on the basis of in vitro buffer values of white, red and heart muscle, suggesting that additional tissues exchange significant amounts of bicarbonate with the extracellular space. It is concluded that physicochemical buffering is not sufficient to account for the observed adjustment of intracellular and extracellular pH and that bicarbonate exchange between body compartments and environment may be the most important regulatory mechamism, responsible for the final adjustment of acid-base balance in dogfish.
在封闭的海水循环系统中，对暴露于10℃温度阶跃变化的大斑星鲨（Sycliorhinus stellaris）进行细胞内/细胞外以及细胞外/海水的碳酸氢盐交换测量。温度变化后，监测血浆（=细胞外空间）和循环海水中碳酸氢盐浓度的变化36小时。根据细胞外空间和海水中碳酸氢盐的变化计算碳酸氢盐的细胞内/细胞外转移。当温度从10℃变为20℃时，观察到碳酸氢盐从细胞内显著转移到细胞外隔室，并从细胞外隔室转移到海水。当温度从20℃降至10℃时，这些转移发生逆转。交换过程在18小时后基本完成。细胞内和细胞外隔室与海水之间交换的碳酸氢盐量大于根据白色、红色和心肌的体外缓冲值预测的量，这表明其他组织与细胞外空间交换了大量的碳酸氢盐。得出的结论是，物理化学缓冲不足以解释观察到的细胞内和细胞外pH值的调节，并且身体隔室与环境之间的碳酸氢盐交换可能是最重要的调节机制，负责最终调节星鲨的酸碱平衡。
