Kasai M, Nunogaki K
Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University, Japan.
J Theor Biol. 1993 Apr 21;161(4):461-80. doi: 10.1006/jtbi.1993.1067.
The time course of tracer ion efflux from vesicles of uniform size, each of which contains an ion channel was theoretically analyzed. It is shown that the apparent flux rate reflects the opening rate of the channel when the flux rate is much higher than the channel gating rates. The theory was also developed for the system of vesicles whose volume is changed by an osmotic pressure jump with permeable solutes. The theory was applied to analyze the results obtained from ion flux measurements with sarcoplasmic reticulum vesicles, where ion fluxes through anion and cation channels have been observed by the tracer method, the volume change-light scattering method and the fluorescence quenching method. The results were successfully interpreted with the present model referring to the results from the electrical single channel recordings.
对大小均匀且每个都包含一个离子通道的囊泡中示踪离子流出的时间进程进行了理论分析。结果表明，当通量率远高于通道门控率时，表观通量率反映了通道的开放率。该理论也针对囊泡系统进行了拓展，该系统的体积会因渗透溶质的渗透压阶跃而改变。该理论被应用于分析用肌浆网囊泡进行离子通量测量所得到的结果，其中通过示踪法、体积变化 - 光散射法和荧光猝灭法观察到了离子通过阴离子和阳离子通道的通量。参照单通道电记录的结果，用当前模型成功解释了这些结果。
