Cullen B M, Michalowski A, Walker H C, Révész L
Int J Radiat Biol Relat Stud Phys Chem Med. 1980 Nov;38(5):525-35. doi: 10.1080/09553008014551341.
The value of the radiobiological oxygen constant K has been found to depend on the concentration of non-protein sulphydryl (NPSH) within the cell. Cells in the exponential phase of growth have a higher concentration of NPSH and a higher value of K than cells in plateau phase. Binding NPSH with N-ethylmaleimide reduced the value of K and conversely, addition of NPSH as dithioerythritol increased the value of K. K also rises with the same time course as NPSH increases, when plateau phase cells are replated into fresh medium. These results support the hypothesis that free-SH groups within the cell compete with oxygen to react with radiation damaged molecules.
已发现放射生物学氧常数K的值取决于细胞内非蛋白质巯基（NPSH）的浓度。处于生长指数期的细胞比处于平台期的细胞具有更高的NPSH浓度和更高的K值。用N-乙基马来酰亚胺结合NPSH会降低K值，相反，添加二硫苏糖醇形式的NPSH会增加K值。当将平台期细胞重新接种到新鲜培养基中时，K也会随着NPSH增加的相同时间进程而升高。这些结果支持了细胞内游离巯基与氧竞争以与辐射损伤分子反应的假说。
