Mela M J
Johnson Research Foundation, Department of Biophysics and Physical Biochemistry, School of Medicine, University of Pennsylvania, Philadelphia, USA.
Biophys J. 1967 Jan;7(1):95-110. doi: 10.1016/S0006-3495(67)86577-9. Epub 2008 Dec 31.
To the revolution-ellipsoidal and spherical membranous shell (cell mitochondrion) are introduced the equations for the calculation of both the modulus of elasticity (Young's modulus) and the stresses, which exist at the membrane. The existing pressure difference between the inner and outer surface of the membrane is calculated in the dilution of seawater media in the osmotic steady state. The experimental results are obtained by using egg cells of the sea urchin, Strongylocentrotus purpuratus. Up to the specific volume of the egg cell (V(E) approximately 35.10(-8) cm(3)) Boyle-van't Hoff's law is valid (defined as the subelastic range) beyond that the elastic stresses exist (elastic range). For the maximum value of the stresses existing at the cell wall one obtains sigma approximately 5.5.10(6) dyne/cm(2) and for the modulus of elasticity E = 1.0.10(7) dyne/cm(2), which is constant when the value of relative strain epsilon(nu) > 15%. The breaking limit by an approximate calculation is sigma(U) approximately 11.10(6) dyne/cm(2). The membrane is assumed to be convoluted and its hypothetical degree of folding was calculated unk = 34%. The results are compared with the values existing in the literature and other types of cells are found to have values of elasticity in the same range as values of the membrane of S. purpuratus. Both compression and cell elastometer methods are criticized and in certain cases results of these methods are considered to belong to the subelastic domain.
针对旋转椭球体和球形膜壳（细胞线粒体），引入了用于计算膜弹性模量（杨氏模量）和应力的方程。膜内外表面之间的现有压力差是在渗透稳态下海水介质稀释过程中计算得出的。实验结果是通过使用紫海胆（Strongylocentrotus purpuratus）的卵细胞获得的。在卵细胞的比容达到特定值（V(E) 约为 35×10⁻⁸ cm³）之前，玻意耳 - 范托夫定律有效（定义为亚弹性范围），超过该值则存在弹性应力（弹性范围）。对于细胞壁处存在的应力最大值，得到 σ 约为 5.5×10⁶ 达因/cm²，对于弹性模量 E = 1.0×10⁷ 达因/cm²，当相对应变 ε(ν) > 15% 时该值恒定。通过近似计算得出的断裂极限为 σ(U) 约为 11×10⁶ 达因/cm²。假设膜是卷曲的，并计算了其假设的折叠度 unk = 34%。将结果与文献中的现有值进行比较，发现其他类型的细胞具有与紫海胆膜相同范围内的弹性值。对压缩法和细胞弹性计法都进行了批评，在某些情况下，认为这些方法的结果属于亚弹性领域。
