VISCOELASTIC PROPERTIES OF ERYTHROCYTE-MEMBRANES IN HIGH-FREQUENCY ELECTRIC-FIELDS
VISCOELASTIC PROPERTIES OF ERYTHROCYTE-MEMBRANES IN HIGH-FREQUENCY ELECTRIC-FIELDS
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DOI：
10.1038/307378a0
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发表时间：
1984-01-01
期刊：
影响因子：
64.8
通讯作者：
SACKMANN, E
中科院分区：
文献类型：
--
作者：
ENGELHARDT, H;GAUB, H;SACKMANN, E
红细胞的高变形性是其通过毛细血管运输所必需的，这主要取决于其盘状形状和质膜的弹性，这可以通过细胞骨架、脂质/蛋白质小叶和糖萼的相互作用来确定。虽然存在测量红细胞静态弹性的技术，但细胞在体内是连续变形的，应力在几秒钟内变化。因此，动态弹性行为对于它们的生理功能至关重要。我们在这里提出了一种新的手段来测量的动态弹性常数的红细胞的基础上的瞬态变形的单个细胞在一个不均匀的高频（HF）电场。通过显微镜，它是可能的，以记录小至200 nm的细胞伸长发生在1毫秒的时间尺度内。一个主要的优点是，细胞的反应是线性的，因此可以更容易地解释理论。我们已经观察到一个蠕变函数组成的两个指数的响应时间为0.1秒和1秒，这可以描述在一个简单的粘弹性模型。在25 °C和15 °C之间，观察到新鲜提取的细胞的膜弹性的显著温度依赖性，但对于胰蛋白酶化的细胞则没有。
The high deformability of erythrocytes which is essential for their transport through the capillaries depends critically on their discoid shape and on the elasticity of the plasma membrane, which may be determined by interactions of the cytoskeleton, the lipid/protein leaflet and the glycocalyx. Although techniques exist for measurement of the static elastic properties of erythrocytes, the cells are continuously deformedin vivo, the stress varying within periods of a few seconds. Thus dynamic elastic behaviour is essential for their physiological function. We present here a novel means of measuring the dynamic elastic constants of the red cell based on the transient deformation of individual cells in an inhomogeneous high-frequency (HF) electric field. By microscopy it is possible to record cellular elongations as small as 200 nm occurring within time scales of 1 ms. A main advantage is that the cellular response is linear and thus can be more readily interpreted theoretically. We have observed a creep function consisting of two exponentials with response times of 0.1 s and 1 s, which can be described in terms of a simple viscoelastic model. A remarkable temperature dependence of the membrane elasticity between 25 °C and 15 °C is observed for freshly drawn cells but not for trypsinized ones.