冷冻对人精子结构及功能的影响

Effects of freezing on human spermatozoal function and structure

目的：研究冷冻对人精子结构和功能的影响。方法：采集健康已生育25～35岁男性供精者精液作标本，7.5％单一甘油为冷冻保护剂(Cryopreservative agent,CPA)，每份精液分别采用速、缓降温法冷冻，冻前、后分别作精液常规分析、精尾低渗肿胀试验、精子超微结构、精子穿卵试验。 结果 ：复温后未加CPA者,均未见有复苏存活的精子；加CPA者，精子存活率、活动率、精尾低渗肿胀率、精子超微结构相对完整的百分率、穿卵率均显著下降,速冻法比缓冻法下降更明显。结论：7.5％单一甘油对人类精子具有显著的冷冻保护作用，精液冻贮对精子的结构及功能均有不同程度的损害，不同的降温速度对人精子产生不同的冷冻损伤，缓冻法降温冻贮人类精液的方法简单经济，能较好地较长时期地保持人精子功能和结构完整性。

Objective: This experiment was designed to evaluate the effects of freezing on human spermatozoal function and structure. Methods: Semen samples were collected from normal fertile 25～35 year old donors, 7.5% pure glycerol was used as cryopreservative agent(CPA),and every sample was frozen at slow cooling rate and fast cooling rate. Results: After freezing－thawing, the whole spermatozoa in the semen without CPA was seen dead；in the semen with CPA, the mean percentage of motility of spermatozoa、spermatozoa tail swelling 、spermatozoa with relatively intact head ultrastructure and zona－free hamster ova penetrated by spermatozoa frozen was significantly lower than that of fresh spermatozoa, and the percentage of every criterion described previously of frozen－thawed spermatozoa cooled at fast rate was significantly lower than that in frozen－thawed spermatozoa cooled at slow rate. Conclusion: Spermatozoal structure and function were damaged to various degrees by freezing－storing－thawing treatment. 7.5% pure glycerol can cryopreserve human spermatozoa, various cooling rates will cause various freezing injury to human spermatozoa, the slow cooling rate is superior to the fast cooling rate and can keep human spermatozoal structure and function fairly well for a relatively long term.