Travis Alexander J, Tutuncu Levent, Jorgez Carolina J, Ord Teri S, Jones Brian H, Kopf Gregory S, Williams Carmen J
Center for Research on Reproduction and Women's Health, Philadelphia, PA 19104, USA.
Biol Reprod. 2004 Jul;71(1):139-45. doi: 10.1095/biolreprod.103.025809. Epub 2004 Feb 25.
In both the mouse and the human, it is a point of controversy whether glucose is necessary for in vitro fertilization. Some of this controversy has resulted from a failure to distinguish between requirements for glucose during sperm capacitation versus requirements during the multistage process of fertilization. Using the mouse as a model, we performed a series of experiments designed to identify specific processes that might require glucose. We observed a positive correlation between increasing glucose concentrations during capacitation and fertilization, and increasing fertilization of zona pellucida (ZP)-intact eggs. These data supported a requirement for glucose in the fertilization medium even when sperm were first capacitated in the presence of 5.5 mM glucose. This glucose requirement was observed for both ZP-intact and ZP-free eggs. During ZP-free in vitro fertilization, some binding and fusion between the plasma membrane of the sperm and egg occurred in the absence of glucose and at concentrations less than 1 mM, suggesting that this substrate is not absolutely required. However, glucose concentrations of 1 mM or higher greatly facilitated both binding and fusion under these conditions. These subtle distinctions suggest that during ZP-free in vitro fertilization, 1 mM glucose represents a threshold level that facilitates binding and fusion. Taken as a whole, the data suggest requirements for glucose during both capacitation and fertilization under normal physiologic conditions.
在小鼠和人类中，葡萄糖对于体外受精是否必要一直存在争议。部分争议源于未能区分精子获能过程中对葡萄糖的需求与受精多阶段过程中对葡萄糖的需求。我们以小鼠为模型进行了一系列实验，旨在确定可能需要葡萄糖的特定过程。我们观察到，在获能和受精过程中葡萄糖浓度增加与透明带（ZP）完整卵子受精率增加之间存在正相关。这些数据支持了受精培养基中需要葡萄糖的观点，即使精子首先在5.5 mM葡萄糖存在的情况下获能。无论是ZP完整的卵子还是无ZP的卵子，都观察到了这种对葡萄糖的需求。在无ZP的体外受精过程中，在没有葡萄糖且浓度低于1 mM的情况下，精子与卵子的质膜之间也会发生一些结合和融合，这表明这种底物并非绝对必需。然而，在这些条件下，1 mM或更高的葡萄糖浓度极大地促进了结合和融合。这些细微差别表明，在无ZP的体外受精过程中，1 mM葡萄糖代表了促进结合和融合的阈值水平。总体而言，数据表明在正常生理条件下，获能和受精过程都需要葡萄糖。
