Jentoft J E, Town C D
J Cell Biol. 1985 Sep;101(3):778-84. doi: 10.1083/jcb.101.3.778.
We have used phosphorus-31 nuclear magnetic resonance to determine intracellular pH in the cellular slime mold Dictyostelium discoideum. We devised an air-lift circulator to maintain the dense cell suspensions in a well-oxygenated and well-stirred state while causing minimal perturbation to the sample flowing through the detector coils. Cells continued to develop normally in this set-up. Spectra acquired under these conditions typically show two peaks in the inorganic phosphate region corresponding to pH values of 7.16 +/- 0.03 and 6.48 +/- 0.02. These peaks are believed to represent the mitochondrial and cytosolic compartments respectively, based on a comparison of these values with published data and the collapse of the two compartments upon addition of the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy)-phenylhydrazone. Dictyostelium cells show a remarkable degree of intracellular pH homeostasis. Both mitochondrial and cytosolic pH remained unchanged as extracellular pH was varied from 4.3 to 8.1. There was also no apparent change in the pH of either compartment after up to 13.5 hours' development in suspension.
我们利用磷-31核磁共振来测定细胞黏菌盘基网柄菌中的细胞内pH值。我们设计了一种气升循环器，以将密集的细胞悬液维持在充分氧合和充分搅拌的状态，同时对流经检测线圈的样品造成最小程度的扰动。细胞在这种设置下继续正常发育。在这些条件下获取的光谱通常在无机磷酸盐区域显示两个峰，分别对应于pH值7.16±0.03和6.48±0.02。基于将这些值与已发表数据进行比较，以及在添加线粒体解偶联剂羰基氰化物4-（三氟甲氧基）苯腙后两个区室的消失，这些峰被认为分别代表线粒体和胞质区室。盘基网柄菌细胞表现出显著程度的细胞内pH稳态。当细胞外pH从4.3变化到8.1时，线粒体和胞质pH均保持不变。在悬浮培养长达13.5小时的发育过程后，两个区室的pH也没有明显变化。
