Lanthanum increases the rat thymocyte cytoplasmic free calcium concentration by enhancing calcium influx.
Lanthanum increases the rat thymocyte cytoplasmic free calcium concentration by enhancing calcium influx.
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DOI：
10.1016/0167-4889(86)90144-8
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发表时间：
1986-04
期刊：
影响因子：
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通讯作者：
Joseph Segal
中科院分区：
文献类型：
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作者：
Joseph Segal
在本研究中，我用Quin2技术研究了La(La~(3+))对大鼠胸腺细胞胞浆游离钙浓度的影响。与La~(3+)对大鼠胸腺细胞内15Ca积累的影响一样，La~(3+)可引起胸腺细胞胞浆游离钙浓度的浓度相关增加。La~(3+)的这种作用起效非常迅速，从加入La~(3+)开始，在约30 S的时间内就明显地表现出来。La3+的最低有效浓度为6μM(高于对照的+22.7%)，在25μM时逐渐增加，达到最大值(高于对照的+100%)。La~(3+)加入无钙培养液中，对负载Quin2的胸腺细胞无影响。此外，La~(3+)对大鼠胸腺细胞的~(45)Ca外流无明显影响，La~(3+)对大鼠胸腺细胞钙-ATPase活性无明显抑制作用。这些结果表明，在大鼠胸腺细胞中，La3+通过增加细胞外钙内流而不是细胞内钙释放来增加细胞质内游离钙浓度。
In the present study, I have examined the effect of lanthanum (La3+) on cytoplasmic free calcium concentration in isolated rat thymocytes employing the quin2 technique. As with its effect on15Ca accumulation in rat thymocytes (Segal, J. and Ingbar, S.H. (1984) Endocrinology, 115, 160–166), La3+produced a concentration-related increase in thymocyte cytoplasmic free calcium concentration. This effect of La3+was very prompt in onset, evident within about 30 s from the time of addition of La3+. The lowest effective concentration of La3+was 6 μM (+22.7% above control), and it increased progressively to reach maximal values at 25 μM (+100% above control). La3+added to quin2-loaded thymocytes suspended in a calcium-free medium was without effect. In addition, La3+had no significant effect on45Ca efflux, and La3+did not inhibit calcium-ATPase activity in the rat thymocytes. These results demonstrate that in rat thymocytes La3+increases cytoplasmic free calcium concentration by increasing the extracellular calcium influx into the cell rather than the release of calcium from an intracellular pool.