Salt A N, Ohyama K, Thalmann R
Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri 63110.
Hear Res. 1991 Nov;56(1-2):29-36. doi: 10.1016/0378-5955(91)90150-8.
The degree to which radial exchange between scala tympani (ST) and scala vestibuli (SV) can occur has not previously been quantified. We have measured the amount of cross-communication in the third turn of the guinea pig cochlea using an ionic tracer, trimethylphenylammonium (TMPA). TMPA was perfused through one scala while TMPA concentrations were measured simultaneously in the perfused and non-perfused scalae. On the basis of the time course of TMPA increase recorded in the non-perfused scala, we were able to calculate rate constants for cross-leak and clearance. Cross-leak in the third turn occurred remarkably rapidly with a rate constant from ST to SV of 0.049 min-1 and from SV to ST of 0.031 min-1. These correspond to transfer half times of 14.2 and 22.4 min respectively. This result demonstrates that ST and SV in the third turn cannot be regarded as independent compartments.
鼓阶（ST）和前庭阶（SV）之间径向交换发生的程度此前尚未被量化。我们使用离子示踪剂三甲基苯基铵（TMPA）测量了豚鼠耳蜗第三圈中的交叉连通量。TMPA被灌注到一个阶中，同时在灌注和未灌注的阶中测量TMPA浓度。根据在未灌注阶中记录的TMPA增加的时间进程，我们能够计算交叉渗漏和清除的速率常数。第三圈中的交叉渗漏非常迅速地发生，从ST到SV的速率常数为0.049 min⁻¹，从SV到ST的速率常数为0.031 min⁻¹。这些分别对应于14.2分钟和22.4分钟的转移半衰期。这一结果表明，第三圈中的ST和SV不能被视为独立的隔室。
