Kondo T, Beutler E
J Lab Clin Med. 1979 Oct;94(4):617-23.
In order to devise a more physiologic system for measuring depletion of red cell ATP levels, the effect of incubating human erythrocytes with 2-deoxyglucose has been investigated. ATP depletion proceeds very slowly at a 20 mM concentration of 2-deoxyglucose, a level which exceeds the Km of hexokinase for this substrate by more than 10-fold. However, at 160 mM concentration of 2-deoxyglucose, ATP depletion proceeds sufficiently rapidly that nearly 90% of ATP has disappeared from the red cell after 2 1/2 hr of incubation. To explain this observation, a number of additional studies were carried out. It was found that 2-deoxyglucose penetrated rapidly into red cells. Phosphorylation of 2-deoxyglucose in red cells was inhibited by both products of the 2-deoxyglucose-phosphorylating reaction, namely, 2-deoxyglucose-6-phosphate and ADP. Inhibition of 2-deoxyglucose phosphorylation was diminished at higher-than-physiologic pH levels. Red cells may be relatively rapidly depleted of ATP by incubation with 100 mM 2-deoxyglucose in a saline-phosphate-buffered medium, pH 7.8. In such rapidly depleted cells, the morphologic changes which formerly were attributed to ATP depletion do not occur.
为了设计出一种更符合生理状态的测量红细胞ATP水平消耗的系统，研究了将人红细胞与2-脱氧葡萄糖一起孵育的效果。在20 mM浓度的2-脱氧葡萄糖下，ATP消耗进行得非常缓慢，该浓度比己糖激酶对该底物的Km值高出10倍以上。然而，在160 mM浓度的2-脱氧葡萄糖下，ATP消耗进行得足够快，孵育2.5小时后，红细胞中近90%的ATP已消失。为了解释这一现象，进行了一些额外的研究。发现2-脱氧葡萄糖能迅速穿透红细胞。2-脱氧葡萄糖磷酸化反应的两种产物，即2-脱氧葡萄糖-6-磷酸和ADP，均抑制红细胞中2-脱氧葡萄糖的磷酸化。在高于生理pH值的水平下，2-脱氧葡萄糖磷酸化的抑制作用减弱。在pH 7.8的磷酸盐缓冲盐溶液中，将红细胞与100 mM 2-脱氧葡萄糖一起孵育，红细胞中的ATP可能会相对迅速地耗尽。在这种迅速耗尽ATP的细胞中，以前归因于ATP耗尽的形态学变化并未发生。
