Chambers E L
J Exp Zool. 1976 Jul;197(1):149-54. doi: 10.1002/jez.1401970118.
The presence of at least 2.5 mM Na during the first several min after insemination is required for the activation of sea urchin eggs. Of those chemical species examined that exist entirely as cations, and which did not activate the unfertilized egg, only Li substitutes for Na. Ammonium and other amines, with pKa values between 9 and 10.8, in the complete absence of Na (a) can induce nuclear activation of unfertilized eggs, and (b) permit the development of the early fertilized egg through the stage that normally requires Na.
受精后最初几分钟内至少存在2.5 mM的钠是海胆卵激活所必需的。在那些完全以阳离子形式存在且未激活未受精卵的化学物质中，只有锂能替代钠。在完全没有钠的情况下，pKa值在9至10.8之间的铵和其他胺类物质，（a）可诱导未受精卵的核激活，（b）使早期受精卵发育至正常需要钠的阶段。
