Oda K, Gibbons W E, Leibo S P
Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX.
J Reprod Fertil. 1992 Aug;95(3):737-47. doi: 10.1530/jrf.0.0950737.
The effect of osmotic changes on fertilized mouse ova was studied by measuring their survival, defined as development into hatching blastocysts, after exposure to various concentrations of ethanediol (ethylene glycol). In addition, a Boyle-van't Hoff plot was derived from exposing ova to hypotonic and hypertonic solutions ranging from 0.1 to 2.8 osmol. Volume of ova was inversely proportional to osmolality over this range. Extrapolation of this relationship yielded a nonosmotic volume of the ova of 22.5%. Eighty-five per cent or more of the ova survived exposure to this wide range of concentrations and developed into blastocysts. The rate of development of ova exposed to anisotonic solutions was the same as that of controls. Ova underwent osmotic shock when abruptly diluted out of concentrated solutions of ethanediol with an isotonic solution. Their survival was highly dependent on the ethanediol concentration with which they had equilibrated before dilution, and the manner, rate and temperature of dilution. The longer the exposure to ethanediol the greater was the sensitivity of the ova to osmotic shock, reflecting permeation of ethanediol into the ova. Osmotic shock could be alleviated by dilution at a high temperature, and prevented by the use of sucrose as an osmotic buffer at 37 degrees C. Identification of the variables that influence osmotic shock of ova will be helpful in the systematic study of their cryopreservation.
通过测量受精小鼠卵子在暴露于不同浓度的乙二醇后发育成孵化囊胚（以此定义为存活）的情况，研究了渗透变化对其的影响。此外，通过将卵子暴露于0.1至2.8渗透压的低渗和高渗溶液中得出了博伊尔 - 范特霍夫图。在此范围内，卵子体积与重量克分子渗透压浓度成反比。外推这种关系得出卵子的非渗透体积为22.5%。超过85%的卵子在暴露于如此广泛的浓度范围后存活并发育成囊胚。暴露于非等渗溶液中的卵子发育速率与对照组相同。当用等渗溶液将卵子从浓缩的乙二醇溶液中突然稀释时，卵子会经历渗透休克。它们的存活高度依赖于稀释前与之平衡的乙二醇浓度，以及稀释的方式、速率和温度。卵子暴露于乙二醇的时间越长，对渗透休克的敏感性就越高，这反映了乙二醇渗透到卵子中。在高温下稀释可减轻渗透休克，在37摄氏度下使用蔗糖作为渗透缓冲剂可防止渗透休克。确定影响卵子渗透休克的变量将有助于对其冷冻保存进行系统研究。
