Machemer H, Eckert R
J Gen Physiol. 1973 May;61(5):572-87. doi: 10.1085/jgp.61.5.572.
Quantitative relations between ciliary reversal and membrane responses were examined in electrically stimulated paramecia. Specimens bathed in 1 mM CaCl(2), 1 mM KCl, and 1 mM Tris-HCl, pH 7.2, were filmed at 250 frames per second while depolarizing current pulses were injected. At current intensities producing only electrotonic shifts the cilia failed to respond. Stimuli which elicited a regenerative response were followed by a period of reversed ciliary beating. With increasing stimulus intensities the latency of ciliary reversal dropped from 30 to 4 ms or less, and the duration of reversal increased from 50 ms to 2.4 s or more; the corresponding regenerative responses increased in amplitude and rate of rise. With progressively larger intracellular positive pulses, electric stimulation became less effective, producing responses with a progressive increase in latency and decrease in duration of reversed beating of the cilia. When 100-ms pulses shifted the membrane potential to +70 mV or more, ciliary reversal was suppressed until the end of the pulse. "Off" responses then occurred with a latency of 2-4 ms independent of further increases in positive potential displacement. These results suggest that ciliary reversal is coupled to membrane depolarization by the influx of ions which produces the regenerative depolarization of the surface membrane. According to this view suppression of the ciliary response during stimulation occurs when the membrane potential approaches the equilibrium potential of the coupling ion, thereby retarding its influx. Previous data together with the present findings suggest that this ion is Ca(2+).
在电刺激的草履虫中研究了纤毛反转与膜反应之间的定量关系。将标本置于1 mM氯化钙、1 mM氯化钾和1 mM Tris-HCl（pH 7.2）中，在注入去极化电流脉冲时，以每秒250帧的速度拍摄。在仅产生电紧张性移位的电流强度下，纤毛没有反应。引发再生反应的刺激之后会有一段时间的纤毛摆动反转。随着刺激强度的增加，纤毛反转的潜伏期从30毫秒降至4毫秒或更短，反转持续时间从50毫秒增加到2.4秒或更长；相应的再生反应的幅度和上升速率增加。随着细胞内正向脉冲逐渐增大，电刺激的效果逐渐减弱，产生的反应中纤毛反转的潜伏期逐渐增加，持续时间逐渐缩短。当100毫秒的脉冲将膜电位转移到+70 mV或更高时，纤毛反转被抑制直到脉冲结束。然后会出现“关闭”反应，潜伏期为2 - 4毫秒，与正向电位位移的进一步增加无关。这些结果表明，纤毛反转通过离子内流与膜去极化耦联，离子内流产生表面膜的再生性去极化。根据这一观点，刺激期间纤毛反应的抑制发生在膜电位接近耦联离子的平衡电位时，从而阻碍其流入。先前的数据与目前的发现共同表明，这种离子是Ca(2+)。
