Connolly J G, Brown I D, Lee A G, Kerkut G A
Comp Biochem Physiol A Comp Physiol. 1985;81(2):293-302. doi: 10.1016/0300-9629(85)90138-0.
Cells of Tetrahymena pyriformis--NT1 were cultured at 38 degrees C (Tg 38 degrees C) and 20 degrees C (Tg 20 degrees C) and their properties investigated over the range 0-40 degrees C. Tg 20 degrees C cells were viable in the range 3-33 degrees C and changes in their properties were readily reversible between 10 degrees C and 30 degrees C. Tg 38 degrees cells were viable in the range 40-10 degrees C and their property changes were immediately reversible in the range 40-23 degrees C. The I-V relations of Tg 38 degrees C cells showed increased excitability as the cells were cooled from 40 degrees C. At 10 degrees C there was a considerable loss of excitability and slope resistance. Cooling Tg 20 degrees C cells from 20 degrees C gave a similar pattern, although over a narrower temperature range. Warming Tg 20 degrees C Tetrahymena above 20 degrees C led to a progressive loss of excitability and the cells were markedly less viable above 35 degrees C. Within physiological limits the regenerative spike magnitude, repolarization time, time to peak and input resistance increased as temperature was lowered, whereas resting potential was diminished. When compared at their growth temperatures and most intermediate temperatures, the value of the various parameters monitored were generally different for the two cultures. The Q10 value for resting potential changes of Tg 20 degrees C cells about 20 degrees C was 1.20. As in T. vorax this was significantly (P less than 0.01) greater than that predicted for a diffusion potential and suggested that T. pyriformis--NT1 may have an electrogenic pump component in its membrane potential.
梨形四膜虫NT1细胞在38℃（Tg 38℃）和20℃（Tg 20℃）下培养，并在0-40℃范围内研究其特性。Tg 20℃细胞在3-33℃范围内存活，其特性变化在10℃至30℃之间易于逆转。Tg 38℃细胞在40-10℃范围内存活，其特性变化在40-23℃范围内可立即逆转。随着Tg 38℃细胞从40℃冷却，其I-V关系显示兴奋性增加。在10℃时，兴奋性和斜率电阻有相当大的损失。将Tg 20℃细胞从20℃冷却也得到类似的模式，尽管温度范围较窄。将Tg 20℃的梨形四膜虫加热到20℃以上会导致兴奋性逐渐丧失，并且细胞在35℃以上明显活力降低。在生理限度内，随着温度降低，再生峰幅度、复极化时间、达到峰值的时间和输入电阻增加，而静息电位降低。当在它们的生长温度和大多数中间温度下进行比较时，两种培养物监测的各种参数值通常不同。Tg 20℃细胞在约20℃时静息电位变化的Q10值为1.20。与嗜热四膜虫一样，这显著（P小于0.01）大于扩散电位预测的值，表明梨形四膜虫NT1的膜电位可能有一个生电泵成分。
