Fischbarg J, Li J, Kuang K, Echevarría M, Iserovich P
Department of Physiology, Columbia University, College of Physicians and Surgeons, New York, New York 10032.
Am J Physiol. 1993 Nov;265(5 Pt 1):C1412-23. doi: 10.1152/ajpcell.1993.265.5.C1412.
Measurements of cell membrane water osmotic permeabilities can be inaccurate because of the technical difficulties inherent to cell volume measurements and because of the presence of an unstirred water layer in contact with the cells. We detail here a method we have developed to quantify transient changes in cell volumes from the intensity of light scattered by cells. For this, we theorize how an unstirred layer originates in a perfusing chamber, and we calculate values for both cell membrane water osmotic permeability and unstirred layer thickness from time transient changes in scattered light. We apply a computer algorithm that finds the best correspondence between experimental data and estimated values. This is done by solving a differential equation governing cell volume changes by numerical integration (Runge-Kutta) and iterating the procedure varying the test values of osmotic permeability and unstirred layer thickness until the best fit is achieved. We exemplify this procedure with experimental results obtained in adherent cultured cells.
细胞膜水渗透渗透率的测量可能不准确，这是由于细胞体积测量固有的技术困难以及与细胞接触的静止水层的存在。我们在此详细介绍一种我们开发的方法，该方法可根据细胞散射光的强度来量化细胞体积的瞬态变化。为此，我们从理论上推测了灌注室中静止层是如何形成的，并根据散射光的时间瞬态变化计算细胞膜水渗透渗透率和静止层厚度的值。我们应用一种计算机算法来找到实验数据与估计值之间的最佳对应关系。这是通过对控制细胞体积变化的微分方程进行数值积分（龙格 - 库塔法）求解，并迭代该过程，改变渗透渗透率和静止层厚度的测试值，直到获得最佳拟合来实现的。我们用在贴壁培养细胞中获得的实验结果来举例说明这个过程。
