A sustained increase in intracellular Ca2+ is required for the acrosome reaction in sea urchin sperm
A sustained increase in intracellular Ca2+ is required for the acrosome reaction in sea urchin sperm
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DOI：
10.1006/dbio.2001.0323
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发表时间：
2001-08-01
影响因子：
2.7
通讯作者：
Darszon, A
中科院分区：
文献类型：
--
作者：
González-Martínez, MT;Galindo, BE;Darszon, A
顶体反应（AR）是许多物种受精所必需的，需要细胞内Ca 2+（[Ca 2 +]（i））的增加。在海胆精子中，AR是由卵胶因子触发的：相关的[Ca 2 +]（i）升高持续数分钟，涉及两个Ca 2+渗透通道。第二通道的开放和AR的开始都发生在用卵因子处理后5秒，这表明这些事件是相关的。一致地，当第二通道的开放被首次检测到时，从海水中除去Ca 2+或加入Ca 2+通道阻断剂抑制AR，并引起[Ca 2 +]（i）的“快速”（t（1/2）= 3-15 s）降低和与AR相关的细胞内pH变化的部分抑制。同时添加NH 4Cl和EGTA，Co 2+，或Ni 2 + 5秒后，鸡蛋的因素防止部分抑制诱发的pH（i）的变化观察，但不逆转AR抑制。因此，精子AR需要由第二Ca 2+通道引起的[Ca 2 +]（i）的持续增加。诱导容量性Ca 2+摄取的试剂（毒胡萝卜素和环匹阿尼酸）的实验表明，在AR期间打开的第二通道可能是钙库操作的Ca 2+通道。(C)北京：科学出版社.
The acrosome reaction (AR), necessary for fertilization in many species, requires an increase in intracellular Ca2+ ([Ca2+](i)). In sea urchin sperm, the AR is triggered by an egg-jelly factor: the associated [Ca2+](i) elevation lasts minutes and involves two Ca2+ permeable channels. Both the opening of the second channel and the onset of the AR occur similar to5 s after treatment with egg factor, suggesting that these events are linked. in agreement, removal of Ca2+ from sea water or addition of Ca2+ channel blockers at the time when opening of the second channel is first detected inhibits AR and causes a "rapid" (t(1/2) = 3-15 s) decrease in [Ca2+](i) and partial inhibition of the intracellular pH change associated with the AR. Simultaneous addition of NH4Cl and either EGTA, Co2+, or Ni2+ 5 s after egg factor prevents the partial inhibition of the evoked pH(i) change observed but does not reverse AR inhibition. Therefore, the sustained increase in [Ca2+](i) caused by the second Ca2+ channel is needed for the sperm AR. Experiments with agents that induce capacitative Ca2+ uptake (thapsigargin and cyclopiazonic acid) suggest that the second channel opened during the AR could be a store-operated Ca2+ channel. (C) 2001 Academic Press.