Du J, Kleinhans F W, Mazur P, Critser J K
Cryobiology Research Institute, Methodist Hospital of Indiana, Indianapolis 46202.
Biochim Biophys Acta. 1994 Aug 24;1194(1):1-11. doi: 10.1016/0005-2736(94)90196-1.
The permeability of human spermatozoa to glycerol and its activation energy were determined using electron paramagnetic resonance (EPR) techniques. EPR was used to monitor the aqueous cell volume change vs. time during the glycerol permeation process using the aqueous spin label 15N-tempone and the membrane impermeable broadening agent potassium trioxalatochromiate (chromium oxalate). The permeation process was completed in tens of seconds, requiring the use of a stopped-flow methodology. The glycerol permeability coefficient (Pg) was determined by fitting a simple theoretical model to the experimental data. The permeabilities of human spermatozoa in 1 molar and 2 molar glycerol at 20 degrees C are (10.3 +/- 0.3).10(-4) cm/min (mean +/- S.D.) and (6.0 +/- 1.4).10(-4) cm/min, respectively. The permeabilities of human spermatozoa in 2 molar glycerol at 30, 20, 10, and 0 degrees C are (8.3 +/- 1.3).10(-4) cm/min, (6.0 +/- 1.4).10(-4) cm/min, (2.1 +/- 0.4).10(-4) cm/min, and (1.1 +/- 0.3).10(-4) cm/min, respectively. The activation energy (Ea) for glycerol permeation between 30 degrees C and 0 degrees C was found to be 11.6 kcal/mol.
利用电子顺磁共振（EPR）技术测定了人类精子对甘油的渗透性及其活化能。在甘油渗透过程中，使用水溶性自旋标记物15N- tempone和膜不可渗透的展宽剂三草酸铬酸钾（草酸铬），通过EPR监测细胞水体积随时间的变化。渗透过程在几十秒内完成，需要使用停流方法。通过将一个简单的理论模型与实验数据拟合来确定甘油渗透系数（Pg）。在20℃时，人类精子在1摩尔和2摩尔甘油中的渗透率分别为(10.3±0.3)×10⁻⁴ cm/min（平均值±标准差）和(6.0±1.4)×10⁻⁴ cm/min。在30℃、20℃、10℃和0℃时，人类精子在2摩尔甘油中的渗透率分别为(8.3±1.3)×10⁻⁴ cm/min、(6.0±1.4)×10⁻⁴ cm/min、(2.1±0.4)×10⁻⁴ cm/min和(1.1±0.3)×10⁻⁴ cm/min。发现在30℃和0℃之间甘油渗透的活化能（Ea）为11.6 kcal/mol。
