RAPID FLOW OF PASSIVE NEUTROPHILS INTO A 4 MU-M PIPETTE AND MEASUREMENT OF CYTOPLASMIC VISCOSITY
RAPID FLOW OF PASSIVE NEUTROPHILS INTO A 4 MU-M PIPETTE AND MEASUREMENT OF CYTOPLASMIC VISCOSITY
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DOI：
10.1115/1.2891184
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发表时间：
1990-08-01
影响因子：
1.7
通讯作者：
HOCHMUTH, RM
中科院分区：
文献类型：
--
作者：
NEEDHAM, D;HOCHMUTH, RM
采用密度分离技术分离来自五个不同个体的中性粒细胞。在恒定的抽吸压力和室温下将总共152个未活化（被动）细胞快速抽吸到直径为4 μ m的移液管中。超过初始屈服阈值的吸入压力为0.5、1和2 kPa，与微循环中遇到的吸入压力相当。这些压力远远超过在电池上形成静态半球形隆起所需的约20 Pa的小抽吸压力。在给定的抽吸压力下，单个细胞的前缘在其流入移液管时被“跟踪”。一个理论的基础上流动的牛顿液体从半球或一个球形部分到一个圆柱体是用来模拟的进入过程。理论和实验都表明，在大部分的进入过程中，细胞的前缘几乎以恒定的速度移动，并在结束时快速加速度。对于来自五个不同个体的细胞，在三种不同的过量抽吸压力下，牛顿理论给出的细胞质粘度为135 ± 1。54 Pa. 2和总进入时间分别为3.3s（0.5kPa）、1.6s（1 kPa）和0.82s（2kPa）。这些结果以及Evans和Yeung在较低抽吸压力下的结果表明，未活化的嗜中性粒细胞内的复杂细胞质表现为粘度为102 Pa·cm-1量级的近牛顿流体。s在抽吸压力和变形率的几乎两个数量级的范围内。
Neutrophils from five different individuals are isolated with a density separation technique. A total of 152 unactivated (passive) cells are rapidly aspirated at constant suction pressure and at room temperature into a pipet with a diameter of 4 .mu.m. The suction pressures in excess of an initial yield threshold are 0.5, 1 and 2 kPa and are comparable to those encountered in the microcirculation. These pressures are well in excess of the small suction pressure of .apprx.20 Pa that is required to form a static hemispherical bump on the cell. AT a given aspiration pressure, the leading edge of an individual cell is "tracked" as it flows into the pipet. A theory based on the flow of a Newtonian liquid from either a hemisphere or a spherical segment into a cylinder is used to model the entry process. Both theory and experiment show that during most of the entry process the leading edge of the cell moves at a nearly constant velocity with a rapid acceleration at the end. For cells from five different individuals at the three different excess aspiration pressures, Newtonian theory gives a cytoplasmic viscosity of 135 .+-. 54 Pa .cntdot. 2 and overall entry times of 3.3s (0.5 kPa), 1.6s (1 kPa) and 0.82s (2 kPa). These results and those of Evans and Yeung at lower aspiration pressures indicate that the complex cytoplasm inside unactivated neutrophils behaves as a nearly Newtonian fluid with a viscosity on the order of 102 Pa .cntdot. s over almost a two order of magnitude range in aspiration pressure and, thus, rate of deformation.