Jin Jian-Yuan, Chen Wen-Ying, Zhou Cheng Xi, Chen Zhang-Hui, Yu-Ying Yuan, Ni Ya, Chan Hsiao Chang, Shi Qi-Xian
Unit of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang, China.
Syst Biol Reprod Med. 2009 Mar-Apr;55(2):97-108. doi: 10.1080/19396360802626648.
This study was designed to determine whether HCO(3)(-) and Cl(-) are required for the activation of the GABA(A) receptor/Cl(-) channel (GBRC) by GABA and the subsequent capacitation of rat sperm. Spermatozoa from adult Sprague Dawley rats were incubated in four different media: modified complete rat fertilization medium (mRFM), Cl(-)-deficient (Cl(-)-DF) mRFM, HCO(3)(-)-DF mRFM, and Cl(-)-DF HCO(3)(-)-DF mRFM, with or without GBRC agonists (GABA and progesterone) or GBRC antagonists (bicuculline and picrotoxin) for 0-6 h under capacitating conditions. Sperm capacitation and hyperactivation were assessed by chlortetracycline staining and computer-assisted sperm analysis, respectively. The results showed that GABA added to the mRFM accelerated capacitation and hyperactivation, followed by increase in the acrosome reaction, reaching maximum value after 5 h. Progesterone also accelerated sperm capacitation and hyperactivation. Bicuculline and picrotoxin, antagonists of GABA, blocked the effects of both GABA and progesterone acceleration of sperm capacitation and hyperactivation. Sperm capacitation required both Cl(-) and HCO(3)(-). These results indicate that activation of GBRC may contribute to sperm capacitation and hyperactivation, and that both HCO(3)(-) and Cl(-) are essential. This is the first report of a close relationship between HCO(3)(-)/Cl(-) transport and the activation of GBRC in rat sperm capacitation and hyperactivation.
本研究旨在确定HCO(3)(-)和Cl(-)是否为γ-氨基丁酸（GABA）激活γ-氨基丁酸A受体/氯离子通道（GBRC）以及随后大鼠精子获能所必需。将成年Sprague Dawley大鼠的精子在四种不同培养基中孵育：改良的完全大鼠受精培养基（mRFM）、氯离子缺乏（Cl(-)-DF）的mRFM、碳酸氢根离子缺乏（HCO(3)(-)-DF）的mRFM以及氯离子和碳酸氢根离子均缺乏（Cl(-)-DF HCO(3)(-)-DF）的mRFM，在获能条件下，添加或不添加GBRC激动剂（GABA和孕酮）或GBRC拮抗剂（荷包牡丹碱和印防己毒素）孵育0至6小时。分别通过金霉素染色和计算机辅助精子分析评估精子获能和超激活。结果显示，添加到mRFM中的GABA加速了获能和超激活，随后顶体反应增加，5小时后达到最大值。孕酮也加速了精子获能和超激活。GABA拮抗剂荷包牡丹碱和印防己毒素阻断了GABA和孕酮加速精子获能和超激活的作用。精子获能需要Cl(-)和HCO(3)(-)两者。这些结果表明，GBRC的激活可能有助于精子获能和超激活，且HCO(3)(-)和Cl(-)两者都是必不可少的。这是关于HCO(3)(-)/Cl(-)转运与大鼠精子获能和超激活过程中GBRC激活之间密切关系的首次报道。
