Williams J B, Kutchai H
Biophys J. 1986 Feb;49(2):453-8. doi: 10.1016/S0006-3495(86)83654-2.
A novel method is used to demonstrate the presence of diffusion boundary layers around erythrocytes following rapid mixing in a stopped-flow spectrophotometer and to estimate the apparent dimensions of the diffusion boundary layers. Pink erythrocyte ghosts labeled on their external surfaces with tetramethyl rhodamine isothiocyanate (TRITC) were mixed in a stopped-flow apparatus with 50 mM NaI in Ringer's solutions. I- is an effective collisional quencher of TRITC fluorescence. TRITC fluorescence after flow stopped decreased monoexponentially with time. The concentration of I- at the cell surface as a function of time was estimated from the dependence of TRITC fluorescence on I- concentration in steady-state experiments. The kinetics of the increase in I- concentration at the cell surface was fit to two diffusional models: a planar erythrocyte ghost bounded by planar diffusion boundary layer and a spherical erythrocyte surrounded by a spherical shell diffusion boundary layer. The planar model best fits the experimental data with a diffusion boundary layer 4.68 microns thick. Using the spherical model the experimental data is best fit by a 6.9 microns diffusion boundary layer.
一种新方法被用于证明在停流分光光度计中快速混合后红细胞周围扩散边界层的存在，并估计扩散边界层的表观尺寸。用异硫氰酸四甲基罗丹明（TRITC）标记其外表面的粉红色红细胞影泡在停流装置中与林格氏溶液中的50 mM NaI混合。I⁻是TRITC荧光的有效碰撞猝灭剂。流动停止后的TRITC荧光随时间呈单指数下降。根据稳态实验中TRITC荧光对I⁻浓度的依赖性，估计细胞表面I⁻浓度随时间的变化。细胞表面I⁻浓度增加的动力学符合两种扩散模型：由平面扩散边界层界定的平面红细胞影泡和被球形壳扩散边界层包围的球形红细胞。平面模型最能拟合实验数据，扩散边界层厚度为4.68微米。使用球形模型，实验数据最适合6.9微米的扩散边界层。
