Bell M, Wang R, Hellstrom W J, Sikka S C
Department of Urology, Tulane University, New Orleans, Louisiana.
J Androl. 1993 Nov-Dec;14(6):472-8.
Sperm membrane damage during cryopreservation reduces the recovery of motile sperm. The present study investigates changes in sperm motility and membrane lipid peroxidation (LPO) in response to two changes in the standard sperm cryopreservation/thawing methodology: 1) the addition of platelet-activating factor (PAF) and pentoxifylline (PTX) as cryoprotective additives, and 2) the alteration of sample thawing time. PAF (1 microM) and PTX (3 mM) were added to fresh sperm samples prior to cryopreservation. After 2 weeks the samples were thawed either quickly (5 minutes at 37 degrees C) or slowly (30 minutes at 4 degrees C) and evaluated for sperm motility and LPO. Thawing time influenced both post-thaw motility and LPO. Samples thawed quickly exhibited a 31% increase in motility recovery (35.2 +/- 4.3% in quick-thaw samples; 24.3 +/- 3.9% in slow-thaw samples) and a 23% lower LPO level (23.3 +/- 3.4% in quick-thaw samples; 30.09 +/- 4.4% in slow-thaw samples) compared to samples thawed slowly. Results also demonstrated that PAF (49 +/- 1.7%) or PTX (42.6 +/- 1.5%) enhance post-thaw motility in comparison to control (35.8 +/- 1.2%), whereas neither PAF nor PTX affect post-thaw LPO (19.1 +/- 2.2% in controls; 20.2 +/- 1.7% in PAF samples; 20.5 +/- 1.4% in PTX samples). These results support observations that there is a negative correlation between sperm motility and LPO in cryopreserved samples. The results also discount the hypothesis that LPO protection is a result of the cryoprotective action of PAF or PTX.
冷冻保存过程中的精子膜损伤会降低活动精子的回收率。本研究调查了标准精子冷冻保存/解冻方法的两项改变对精子活力和膜脂质过氧化（LPO）的影响：1）添加血小板活化因子（PAF）和己酮可可碱（PTX）作为冷冻保护添加剂；2）改变样品解冻时间。在冷冻保存前，将PAF（1微摩尔）和PTX（3毫摩尔）添加到新鲜精子样品中。两周后，将样品快速（37摄氏度下5分钟）或缓慢（4摄氏度下30分钟）解冻，并评估精子活力和LPO。解冻时间影响解冻后的活力和LPO。与缓慢解冻的样品相比，快速解冻的样品活力回收率提高了31%（快速解冻样品为35.2±4.3%；缓慢解冻样品为24.3±3.9%），LPO水平降低了23%（快速解冻样品为23.3±3.4%；缓慢解冻样品为30.09±4.4%）。结果还表明，与对照组（35.8±1.2%）相比，PAF（49±1.7%）或PTX（42.6±1.5%）可提高解冻后的活力，而PAF和PTX均不影响解冻后的LPO（对照组为19.1±2.2%；PAF样品为20.2±1.7%；PTX样品为20.5±1.4%）。这些结果支持了冷冻保存样品中精子活力与LPO之间存在负相关的观察结果。结果也否定了LPO保护是PAF或PTX冷冻保护作用结果的假设。
