Erecińska M, Deas J, Silver I A
Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia 19104-6084, USA.
J Neurochem. 1995 Dec;65(6):2765-72. doi: 10.1046/j.1471-4159.1995.65062765.x.
The effect of [H+] on the rate of glycolysis was investigated in glioma C6 and fibroblast BHK-21 cells and in synaptosomes from rat brain. The rates of lactate production at an extracellular pH (pHe) of 6.2, 7.4, and 7.8 were correlated with intracellular [ATP], [ADP], and [P(i)] ([ATP]i, [ADP]i, and [P(i)]i, respectively) and, when relevant, creatine phosphate (PCr) as well as with the levels of several glycolytic intermediates. In C6 cells cytosolic [H+] was measured simultaneously together with [Ca2+], [K+], [Na+], and membrane potentials. In all three systems studied, an increase in [H+]e suppressed whereas a fall enhanced the rate of lactate generation. Changes in pHe produced no simple correlation between the amount of lactate formed and alterations either in the absolute [ATP], [ADP], [P(i)], and [PCr] or their ratios but did correlate with the levels of glycolytic intermediates. Higher [fructose-1,6-bisphosphate] and [glyceraldehyde-3-phosphate] and lower [glucose-6-phosphate] and [fructose-6-phosphate] accompanied faster glycolytic activity. Addition of rotenone markedly enhanced glycolysis at all pHe values studied. The increases were larger at higher [H+] so that the rate of lactate generation was only slightly lower at pH 6.2 than at 7.4 or 7.8. With rotenone present, [ATP] (and where relevant [PCr]) fell and [ADP] and [P(i)] rose under all pHe conditions. Simultaneously [glucose-6-phosphate] and [fructose-6-phosphate] decreased whereas [fructose-1,6-bisphosphate] and [glyceraldehyde-3-phosphate] increased; the levels of the last two were similar at pH 6.2 and 7.4.(ABSTRACT TRUNCATED AT 250 WORDS)
在胶质瘤C6细胞、成纤维细胞BHK - 21以及大鼠脑突触体中研究了[H⁺]对糖酵解速率的影响。在细胞外pH（pHe）为6.2、7.4和7.8时的乳酸生成速率与细胞内[ATP]、[ADP]和[P(i)]（分别为[ATP]i、[ADP]i和[P(i)]i）相关，相关时还与磷酸肌酸（PCr）以及几种糖酵解中间产物的水平相关。在C6细胞中，同时测量了胞质[H⁺]以及[Ca²⁺]、[K⁺]、[Na⁺]和膜电位。在所研究的所有三个系统中，[H⁺]e升高会抑制而降低则会增强乳酸生成速率。pHe的变化在形成的乳酸量与绝对[ATP]、[ADP]、[P(i)]和[PCr]的改变或它们的比率之间未产生简单的相关性，但与糖酵解中间产物的水平相关。较高的[果糖 - 1,6 - 二磷酸]和[甘油醛 - 3 - 磷酸]以及较低的[葡萄糖 - 6 - 磷酸]和[果糖 - 6 - 磷酸]伴随着更快的糖酵解活性。添加鱼藤酮在所有研究的pHe值下均显著增强糖酵解。在较高的[H⁺]时增加幅度更大，以至于在pH 6.2时乳酸生成速率仅略低于pH 7.4或7.8时。存在鱼藤酮时，在所有pHe条件下[ATP]（以及相关时的[PCr]）下降而[ADP]和[P(i)]升高。同时，[葡萄糖 - 6 - 磷酸]和[果糖 - 6 - 磷酸]降低，而[果糖 - 1,6 - 二磷酸]和[甘油醛 - 3 - 磷酸]升高；后两者在pH 6.2和7.4时的水平相似。（摘要截于250字）
