Ability of repetitive Ca2+ spikes to stimulate prolactin release is frequency dependent.
Ability of repetitive Ca2+ spikes to stimulate prolactin release is frequency dependent.
复制标题
重复 Ca2 峰值刺激催乳素释放的能力取决于频率。
DOI：
10.1016/0006-291x(89)92794-0
复制
发表时间：
1989
影响因子：
3.1
通讯作者：
Dannies,PS
中科院分区：
文献类型：
--
作者：
Law,GJ;Pachter,JA;Dannies,PS
单个细胞胞浆游离Ca ~（2+）（[Ca ~（2+）]c）浓度的测量经常显示[Ca ~（2+）] c的周期性瞬变而不是持续升高的水平。为了确定在垂体前叶细胞中，如果这种短暂和重复的[Ca 2 +] c瞬变刺激催乳素释放，我们使用了灌流系统与细胞加载荧光Ca 2+指示剂，indo-1。100 mM KCl的1秒脉冲引起[Ca 2 +] c增加，半峰宽约为18秒，催乳素分泌几乎同时增加。随后的氯化钾脉冲每一个引起的增加[Ca 2 +] c和催乳素释放是相同的第一个，脉冲频率为每两分钟一次。然而，将频率增加到每分钟1次脉冲或每30秒1次脉冲，导致每个脉冲释放的催乳素量连续下降，即使每个脉冲引起类似的峰值Ca 2+反应。这些发现表明，细胞变得适应[Ca 2 +]的短暂增加足够频繁。细胞可以使用频率编码的Ca 2+信号来刺激低频率下的催乳素释放，以防止在较高频率下发生的适应。
Measurements of concentrations of cytosolic free Ca2+([Ca2+]c) in individual cells has frequently demonstrated periodic transients in [Ca2+]crather than sustained elevated levels. To determine in anterior pituitary cells if such short and repetitive [Ca2+]ctransients stimulated prolactin release, we used a perifusion system with cells loaded with the fluorescent Ca2+-indicator, indo-1. A one second pulse of 100 mM KCl caused an increase in [Ca2+]cwith a half peak width of about 18 seconds and an almost coincident increase in prolactin secretion. Subsequent pulses of KCl each caused increases in [Ca2+]cand prolactin release that were the same as the first, up to a pulse frequency of one every two minutes. Increasing the frequency to 1 pulse every minute or 1 pulse every 30 seconds, however, resulted in a serial decline in the amount of prolactin released by each pulse even though each pulse caused a similar peak Ca2+response. These findings demonstrate that cells become adapted to transient increases in [Ca2+]coccur frequently enough. Cells may use frequency-encoded Ca2+signals to stimulate release of prolactin at low frequency to prevent the adaptation that occurs at higher frequencies.