Regulatory volume decrease in COS-7 cells at 22 掳C and its influence on the Boyle van鈥檛 Hoff relation and the determination of the osmotically inactive volume

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• 作者：Diana Peckys^a ; ^b ; ^{diana.peckys@inm-gmbh.de} ; Peter Mazur^a
• 关键词：Boyle van&rsquo ; t Hoff plot ; Cell volume regulation ; COS-7 cells ; osmotic parameters
• 刊名：Cryobiology
• 出版年：2012
• 期刊代码：166_00112240
• 类别：bio
• 出版时间：August, 2012
• 卷：65
• 期：1
• 页码：74-78
• 文件大小：509 K

摘要

Cryobiological analyses assume that the direction and rate of water movements across cell membranes and equilibrium cell volumes are determined solely by differences in the chemical potentials of intra- and extra-cellular water. A consequence of this assumption is that cells obey the Boyle van鈥檛 Hoff (BvH) law which states that cell volumes are a linear function of reciprocal osmolality. Extrapolation of the BvH plot to infinite osmolality yields a quantity b, the fractional volume of the cell occupied by solids. In many cells, however, a cell volume excursion above the isotonic volume initiates an energy-requiring response that causes the swollen cells to shrink back to or towards isotonic volume. It is referred to as regulatory volume decrease (RVD). We have observed a strong RVD in COS-7 cells. If not eliminated by keeping exposure times short, this RVD produces a b that is 60%too high (0.48 vs. 0.30). These results indicate the importance of examining cells for volume regulatory mechanisms before performing measurements to determine their osmotic parameters.