Zs-Nagy I
F. Verzár International Laboratory for Experimental Gerontology (VILEG), Department of Gerontological Research, Ancona, Italy.
Scanning Microsc. 1989 Jun;3(2):473-80; discussion 481-2.
The freeze-fracture, freeze-drying (FFFD) method of biological bulk specimen preparation combined with quantitative X-ray microanalysis is suitable for the measurement of intracellular concentrations of biologically relevant elements in human biopsy or experimental animal materials. Especially useful information can be obtained regarding the intracellular Na+/K+ ratios being independent of the actual (and unknown) water content of the cytoplasm. The sustained increase of this ratio indicates a sustained depolarization of the cell membrane. These data are of importance from the point of view of the membrane hypothesis of mitogenesis (MHM). It has been revealed that the distribution histograms of the intracellular Na+/K+ ratio display a very significant broadening and an increase of the average values in human urogenital, thyroid and laryngeal tumors, as well as in experimentally induced cell proliferation models. Although MHM has been claimed to be invalid on the basis of some atomic absorption measurements of the intracellular monovalent ion concentrations as well as of some in vitro results obtained with amiloride, this review paper demonstrates that MHM may still be a valid hypothesis for the explanation of mitotic regulation.
生物大块标本制备的冷冻断裂、冷冻干燥（FFFD）方法与定量X射线微分析相结合，适用于测量人体活检或实验动物材料中生物相关元素的细胞内浓度。特别是可以获得与细胞内Na+/K+比率相关的有用信息，该比率与细胞质的实际（且未知）含水量无关。该比率的持续增加表明细胞膜的持续去极化。从有丝分裂发生的膜假说（MHM）的角度来看，这些数据很重要。已经发现，在人类泌尿生殖系统、甲状腺和喉部肿瘤以及实验诱导的细胞增殖模型中，细胞内Na+/K+比率的分布直方图显示出非常显著的展宽和平均值的增加。尽管基于一些细胞内单价离子浓度的原子吸收测量以及用氨氯吡咪获得的一些体外结果，有人声称MHM是无效的，但这篇综述文章表明，MHM可能仍然是解释有丝分裂调节的一个有效假说。
