Noiles E E, Mazur P, Watson P F, Kleinhans F W, Critser J K
Center for Reproduction and Transplantation Immunology, Methodist Hospital of Indiana, Inc., Indianapolis 46202.
Biol Reprod. 1993 Jan;48(1):99-109. doi: 10.1095/biolreprod48.1.99.
Four experiments were conducted to determine the permeability coefficient of human sperm to water (Lp) and its activation energy (Ea). Critical tonicity (tonicity at which 50% of the cells swell and lyse) was determined by equilibrating sperm to 22 degrees C (experiments 1a and 1b), 30, 22, 8, or 0 degrees C (experiment 2a), and 0, -1, -3, -5, or -7 degrees C (experiment 2b) and then exposing them to various hypotonic media (215-3 mOsm). For Lp determination, sperm were equilibrated to 30, 22, 8, or 0 degrees C (experiment 3a), 8, 0, or -3 degrees C (experiment 3b), and -1, -3, -5, or -7 degrees C (experiment 3c), and then were exposed for increasing times to hypotonic (40 mOsm) media. Activation energies were calculated from the results of the latter experiments (experiment 4). Results indicate a temperature-dependent (p < 0.05) critical tonicity, with sperm exhibiting an increased membrane fragility at 8, 0, and -7 degrees C, relative to 30, 22, -1, -3, or -5 degrees C (67.5 +/- 2.4, [mean +/- SEM], 62.7 +/- 2.3, and 61.9 +/- 3.7 mOsm vs. 57.4 +/- 3.4, 57 +/- 1.2, 54.8 +/- 3.4, 60.1 +/- 5.3, and 59.8 +/- 5.2 mOsm, respectively). Human sperm have an Lp of 2.40 +/- 0.20 microns/min/atm at 22 degrees C and an Ea of 3.92 +/- 0.59 kcal/mol between 30 and -7 degrees C. The Ea for cells incubated at temperatures above 0 degrees C (3.92 kcal/mol) show an apparent discontinuity (p < 0.004) in water permeability in supercooled conditions (7.48 kcal/mol). These data suggest that 1) human sperm have a high Lp and low Ea, relative to other cell types, above 0 degrees C; and 2) this high Lp and its low Ea change significantly below 0 degrees C.
进行了四项实验以确定人类精子对水的渗透系数（Lp）及其活化能（Ea）。通过将精子在22℃（实验1a和1b）、30℃、22℃、8℃或0℃（实验2a）以及0℃、-1℃、-3℃、-5℃或-7℃（实验2b）下平衡，然后将它们暴露于各种低渗介质（215 - 3 mOsm）中来确定临界张力（50%的细胞肿胀并裂解时的张力）。为了测定Lp，将精子在30℃、22℃、8℃或0℃（实验3a）、8℃、0℃或 - 3℃（实验3b）以及 - 1℃、-3℃、-5℃或 - 7℃（实验3c）下平衡，然后将它们暴露于低渗（40 mOsm）介质中不同时间。根据后一组实验（实验4）的结果计算活化能。结果表明临界张力与温度有关（p < 0.05），相对于30℃、22℃、-1℃、-3℃或 - 5℃，精子在8℃、0℃和 - 7℃时膜脆性增加（分别为67.5±2.4，[平均值±标准误]，62.7±2.3，和61.9±3.7 mOsm对57.4±3.4，57±1.2，54.8±3.4，60.1±5.3，和59.8±5.2 mOsm）。人类精子在22℃时的Lp为2.40±0.20微米/分钟/大气压，在30℃至 - 7℃之间的Ea为3.92±0.59千卡/摩尔。在0℃以上温度孵育的细胞的Ea（3.92千卡/摩尔）在过冷条件下（7.48千卡/摩尔）的水渗透性上表现出明显的不连续性（p < 0.004）。这些数据表明：1）相对于其他细胞类型，人类精子在0℃以上具有高Lp和低Ea；2）这种高Lp及其低Ea在0℃以下会发生显著变化。
