Lewis R, Dhanani N, Ranadive N S
Can J Biochem Cell Biol. 1983 Jan;61(1):72-8. doi: 10.1139/o83-010.
Rat mast cells, stimulated for histamine release by compound 48/80 or lysosomal cationic protein, take up 45Ca2+ from he extracellular fluid. This uptake is inhibited by diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride, and the inhibitors of energy metabolism. It was seen previously, when the release process is divided into two stages by activating the cells at 0 degrees C, the uptake of 45Ca2+ occurs during the release stage of the reaction. In the present studies, it was found that when cells activated at low temperatures were allowed to stand at 10 degrees C in the presence of 45Ca2+, the uptake of radioactive calcium increased in the first 15 min and then decreased to the levels of unstimulated cells. On the other hand, the release of histamine from the activated cells upon warming to 37 degrees C progressively decreased with an increase in time at 10 degrees C. These results suggest that during the decay of the active state the levels of intracellular exchangeable calcium pool are increased. For 45Ca2+ to be pumped out after the decay, there has to be net gain in intracellular calcium concentration during the first 15 min at 10 degrees C. The increase in membrane permeability to calcium appears to be due to the activation of a transient event.
用化合物48/80或溶酶体阳离子蛋白刺激大鼠肥大细胞以释放组胺时，肥大细胞会从细胞外液摄取45Ca2+。这种摄取受到二异丙基氟磷酸酯、苯甲基磺酰氟以及能量代谢抑制剂的抑制。先前曾观察到，当在0℃激活细胞从而将释放过程分为两个阶段时，45Ca2+的摄取发生在反应的释放阶段。在本研究中，发现当在45Ca2+存在的情况下，将在低温下激活的细胞置于10℃时，放射性钙的摄取在最初15分钟内增加，然后降至未刺激细胞的水平。另一方面，当升温至37℃时，激活细胞释放组胺的量随着在10℃下时间的增加而逐渐减少。这些结果表明，在活性状态衰减期间，细胞内可交换钙池的水平会增加。为了在衰减后将45Ca2+泵出，在10℃下的最初15分钟内细胞内钙浓度必须有净增加。膜对钙通透性的增加似乎是由于一个短暂事件的激活所致。
