A proton-dependent zinc uptake in PC12 cells
A proton-dependent zinc uptake in PC12 cells
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DOI：
10.1007/s11064-004-2438-6
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发表时间：
2005-02-01
影响因子：
4.4
通讯作者：
Colvin, RA
中科院分区：
文献类型：
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作者：
Balaji, RV;Colvin, RA
通过对嗜铬细胞瘤(PC12)细胞进行“酸负荷”来调节细胞内的pH，并研究了这种变化对放射性锌摄取的影响。结果发现，在装入质子的细胞中，锌的摄取被刺激，而不会引起细胞内pH的任何可测量的变化。为了证实我们的假设，即由于锌进入的质子通量太小而无法测量，我们计算了由于锌进入而预期的pH变化。PC12电池的本征缓冲容量被确定为8.03 mm/pH单位，并被用于这些计算。结果发现，在本实验条件下，在5分钟的孵育条件下，锌的摄取可以引起每分钟0.000277个pH单位的pH变化(假设锌与质子的化学计量比为1：2)。这项研究为理解细胞内pH在导致锌进入细胞中所起的作用增加了一个新的维度。
Intracellular pH in pheochromocytoma (PC12) cells was manipulated by 'acid loading' the cells and the effect of such a change on radioactive zinc uptake was studied. It was found that zinc uptake was stimulated in cells loaded with protons without causing any measurable change in the intracellular pH. To confirm our assumption that the proton flux due to zinc entry is too small to be measured, we calculated the pH change that one would expect because of zinc influx. The intrinsic buffer capacity of PC12 cells was determined to be 8.03 mM/pH unit and was used in these calculations. It was found that at the five-minute incubation, zinc uptake occurring under our experimental conditions could cause a pH change of 0.000277 pH units per minute (assuming a 1:2 zinc:proton stoichiometry). This study adds a new dimension towards understanding the role played by intracellular pH in causing zinc entry into cells.