胞质游离钙水平升高不足导致排卵后老化诱导的大鼠自发卵激活失败。
An insufficient increase of cytosolic free calcium level results postovulatory aging-induced abortive spontaneous egg activation in rat.
机构信息
Cell Physiology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
出版信息
J Assist Reprod Genet. 2013 Jan;30(1):117-23. doi: 10.1007/s10815-012-9908-6. Epub 2012 Dec 14.
PURPOSE
The present study was aimed to find out whether postovulatory aging-induced abortive spontaneous egg activation (SEA) is due to insufficient increase of cytosolic free Ca(2+) level.
METHODS
Immature female rats (22-24 days old) were subjected to superovulation induction protocol. Eggs were collected 14, 17 and 19 h post-hCG surge to induce in vivo egg aging. The eggs were collected 14 h post-hCG surge and cultured in vitro for 3, 5 and 7 h to induce in vitro egg aging. The morphological changes, rate of abortive SEA, chromosomal status and cytosolic free Ca(2+) levels were analyzed.
RESULTS
Postovulatory aging induced morphological features characteristics of abortive SEA in a time-dependent manner in vivo as well as in vitro. The extracellular Ca(2+) increased rate of abortive SEA during initial period of culture, while co-addition of a nifedipine (L-type Ca(2+) channel blocker) protected against postovulatory aging-induced abortive SEA. However, CI induced morphological features characteristics of egg activation (EA) in a dose-dependent manner. As compare to control, an increase of cytosolic free Ca(2+) level (1.42 times) induced abortive SEA, while further increase of cytosolic free Ca(2+) level (2.55 times) induced EA.
CONCLUSION
Our results show that an insufficient cytosolic free Ca(2+) level is associated with postovulatory aging -induced abortive SEA, while furthermore increase is required to induce EA in rat.
目的
本研究旨在探讨卵母细胞排卵后老化导致自发激活失败（SEA）是否是由于胞质游离钙（Ca(2+)）水平升高不足所致。
方法
对 22-24 日龄的雌性大鼠进行超排卵诱导。注射 hCG 后 14、17 和 19 小时收集卵子以诱导体内卵母细胞老化。注射 hCG 后 14 小时收集卵子并进行体外培养 3、5 和 7 小时以诱导体外卵母细胞老化。分析形态变化、自发激活失败率、染色体状态和胞质游离 Ca(2+)水平。
结果
排卵后老化以时间依赖的方式在体内和体外诱导形态上具有自发激活失败特征。在培养的初始阶段，细胞外 Ca(2+)增加自发激活失败率，而添加硝苯地平（L 型钙通道阻滞剂）可防止排卵后老化引起的自发激活失败。然而，CI 以剂量依赖的方式诱导卵母细胞激活（EA）的形态特征。与对照组相比，胞质游离 Ca(2+)水平升高（1.42 倍）诱导自发激活失败，而进一步增加胞质游离 Ca(2+)水平（2.55 倍）则诱导 EA。
结论
我们的结果表明，胞质游离 Ca(2+)水平不足与排卵后老化诱导的自发激活失败有关，而进一步增加则需要诱导大鼠的 EA。
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