Mohr F C, Fewtrell C
J Biol Chem. 1987 Aug 5;262(22):10638-43.
The proton ionophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) inhibited antigen-stimulated secretion and calcium influx in rat basophilic leukemia cells. In a glucose-free solution the inhibitory effects of CCCP were due to a decrease in the intracellular ATP concentration; however, when glucose was present there was no decrease in ATP. Instead, we found that in a glucose-containing saline solution, CCCP inhibited antigen-stimulated calcium uptake because it depolarized the plasma membrane, which in rat basophilic leukemia cells inhibits antigen-stimulated calcium uptake. In the presence of glucose, relatively low concentrations of CCCP inhibited calcium uptake while higher concentrations were required to inhibit secretion. In contrast, the initial antigen-stimulated rise in cytoplasmic calcium, measured with the fluorescent calcium indicator quin2, was not inhibited by CCCP. This suggests that the release of calcium from intracellular stores might, in some cases, be sufficient to support antigen-stimulated secretion. In the presence of CCCP the pH gradient becomes important for regulating the membrane potential across the plasma membrane. When cells were depolarized with CCCP and the external pH was increased, the membrane potential returned to resting levels and antigen-stimulated calcium uptake was restored. Inhibition of antigen-stimulated secretion by higher concentrations of CCCP could also be reversed by increasing the external pH.
质子离子载体羰基氰化物间氯苯腙（CCCP）可抑制大鼠嗜碱性白血病细胞中抗原刺激的分泌和钙内流。在无糖溶液中，CCCP的抑制作用是由于细胞内ATP浓度降低；然而，当存在葡萄糖时，ATP没有降低。相反，我们发现在含葡萄糖的盐溶液中，CCCP抑制抗原刺激的钙摄取是因为它使质膜去极化，而在大鼠嗜碱性白血病细胞中，质膜去极化会抑制抗原刺激的钙摄取。在有葡萄糖存在的情况下，相对低浓度的CCCP抑制钙摄取，而抑制分泌则需要更高的浓度。相比之下，用荧光钙指示剂喹啉2测量的抗原刺激后细胞质钙的初始升高不受CCCP抑制。这表明在某些情况下，从细胞内储存库释放的钙可能足以支持抗原刺激的分泌。在存在CCCP的情况下，pH梯度对于调节跨质膜的膜电位变得很重要。当细胞用CCCP去极化且外部pH升高时，膜电位恢复到静息水平，抗原刺激的钙摄取也得以恢复。高浓度CCCP对抗原刺激分泌的抑制作用也可通过提高外部pH来逆转。
