不同复温方法对液氮保存人同种瓣活性影响的实验研究

Experimental study on the effect of different thawing rate on viability of cryopreserved human aortic valvehomograft in liquid nitrogen

寻找一种能最大程度保持液氮贮存人同种主动脉瓣活性的复温方法。方法同种主动脉瓣（ｎ＝３６）随机分为６组，Ⅰ组为新鲜同种主动脉瓣，Ⅱ～Ⅵ组经液氮保存３月后，分别采用①４２℃水浴复温（Ⅱ组），②（１．０±０．２）℃／ｍｉｎ（Ⅲ组），③（４．０±０．５）℃／ｍｉｎ（Ⅳ组），④（１０．０±２．０）℃／ｍｉｎ（Ⅴ组）；⑤（３０．０±４．５）℃／ｍｉｎ（Ⅵ组）。将同种主动脉瓣复温至４℃，对所有同种主动脉瓣进行台盼蓝染色活细胞计数、２４小时葡萄糖代谢率测定，氰化胸腺嘧啶脱氧核甙（３Ｈ－ＴｄＲ）参入、瓣膜组织培养。结果上述指标Ⅰ组显著优于其余各组（Ｐ＜０．０５），Ⅳ组优于Ⅱ、Ⅲ、Ⅴ、Ⅵ组（Ｐ＜０．０５）。组织培养Ⅰ组细胞生长优于其余各组，且早于各组３～４天。结论不同复温方法对同种主动脉瓣活性影响不同，以４℃／ｍｉｎ匀速复温法对同种主动脉瓣活性影响最轻。

Objective To find a good thawing method which can maximally maintain the viability ofhuman aortic valve homograft (AVH). Method Thirty-six AVH were randomly divided into 6 groups:Fresh AVH was in group 1, and the other 5 AVHs were cryopreserved in liquid nitrogen for 3 months, thenthawed to 4℃ at the following rate: 42℃ water-bath thawing (group 2), 1. 0±0. 54℃ /min (group 3), 4. 0±0. 54℃ /min (group 4), 10.0±2. 0℃/min (group 5), 30.0±4.5℃/min (group 6). The effects were evaluated by the following criteria: trypan blue staining fro living cell counting, 24 h glucose metabolic rate,3H-TdR incorporation, and leaflet tissue culture. Result Living cell counting, glucose metabolic rate and 3 HTdR incorporation in group 1 were significantly higher than in the other groups (P<0.05), and in group 4significantly. higher than in groups 2, 3, 5 and 6 (P<0.05). Cell growth in tissue culture of group 1 was 3 to4 days earlier than the other groups. Conclusion Liquid nitrogen caused certain degrees of damage to cryopreserved AVH. 4℃/min thawing caused less damage to cryopreserved AVH.