California National Primate Research Center, University of California, Davis, CA 95616, USA.
Cryobiology. 2009 Dec;59(3):268-74. doi: 10.1016/j.cryobiol.2009.08.002. Epub 2009 Aug 15.
The present study evaluated the interactions among pre-cooling, cryoprotectant, cooling, and thawing for rhesus monkey sperm using a four-way factorial design. Specifically, pre-cooling and thawing were evaluated for two conditions: slow vs. fast. Cooling was evaluated at four rates of 5, 29, 200, and 400 degrees C/min. The types of cryoprotectant involved combinations of egg yolk and glycerol, egg yolk and ethylene glycol, and egg yolk alone without permeable cryoprotectants or buffer alone with glycerol but without egg yolk. Our findings showed strong interactions among cryoprotectants, cooling, and thawing rates, but not pre-cooling rate, on post-thaw motility and forward progression. The optimal combination of cooling and thawing for maximum post-thaw survival depended on the types of cryoprotectant. When glycerol was used as a permeable cryoprotectant in the presence of egg yolk, slow thawing yielded similar success as fast thawing in some males. However, when glycerol was replaced with ethylene glycol for the same treatment, post-thaw motility was significantly lower in samples that were thawed slowly than those that were thawed rapidly. In the absence of permeable cryoprotectant but the presence of egg yolk, fast cooling was always favorable. On the contrary, in the absence of egg yolk but the presence of permeable cryoprotectant (glycerol), post-thaw motility was significantly reduced especially when samples were thawed slowly. Generally, fast thawing was superior to slow thawing regardless of the types of cryoprotectant or cooling rates, and glycerol in the presence of egg yolk yielded the highest post-thaw motility in all treatment groups.
本研究采用四因素析因设计评估了猕猴精子预冷、保护剂、冷却和复温过程中的相互作用。具体来说，预冷和复温分别评估了两种条件：慢速和快速。冷却分别在 5、29、200 和 400°C/min 四种速率下进行评估。保护剂涉及蛋黄和甘油、蛋黄和乙二醇以及蛋黄单独（无渗透性保护剂）或仅含有甘油的缓冲液（无蛋黄）的组合。我们的研究结果表明，在复温后运动和前向运动方面，保护剂、冷却和复温速率之间存在强烈的相互作用，但预冷速率没有相互作用。最佳的冷却和复温组合取决于保护剂的类型，以获得最大的复温后存活率。当甘油作为渗透性保护剂存在于蛋黄中时，在一些雄性中，缓慢复温与快速复温的成功率相似。然而，当甘油被乙二醇替代用于相同的处理时，缓慢复温的样品的复温后运动能力显著低于快速复温的样品。在没有渗透性保护剂但存在蛋黄的情况下，快速冷却总是有利的。相反，在没有蛋黄但存在渗透性保护剂（甘油）的情况下，尤其是当样品缓慢复温时，复温后运动能力显著降低。一般来说，无论保护剂的类型或冷却速率如何，快速复温都优于慢速复温，并且在所有处理组中，蛋黄存在时甘油可获得最高的复温后运动能力。
