Barkai A I, Meltzer H L
J Neurosci. 1982 Sep;2(9):1322-8. doi: 10.1523/JNEUROSCI.02-09-01322.1982.
Since neuronal activity is critically related to both intra- and extracellular calcium ion concentrations, there must be a mechanism for regulating the transfer of calcium from the blood into the extracellular environment of the brain. The data presented here support the hypothesis that, within or close to the site of passive permeation of calcium in the choroid plexus, there is a calcium pump capable of recycling the filtered calcium back into the capillary circulation. This pump can be blocked by ruthenium red, a known inhibitor of active calcium transport. The activity of the calcium pump is shown to increase in proportion to the concentration of calcium in the cerebroventricular fluid. Its physiological role therefore would be to insure that the calcium concentration available to the brain will be maintained within a narrow range even in the presence of severe hypercalcemic states.
由于神经元活动与细胞内和细胞外的钙离子浓度密切相关，因此必然存在一种机制来调节钙从血液向脑的细胞外环境的转运。本文提供的数据支持以下假说：在脉络丛中钙被动渗透的部位或其附近，存在一种钙泵，能够将滤过的钙再循环回毛细血管循环中。这种泵可被钌红阻断，钌红是一种已知的活性钙转运抑制剂。已证明钙泵的活性与脑室液中钙的浓度成比例增加。因此，其生理作用是确保即使在严重高钙血症状态下，大脑可利用的钙浓度也能维持在狭窄范围内。
