硫酸软骨素对液氮深低温保存的同种异体主动脉瓣的保护作用

Protective effect of chondroitin sulfate on homograft aortic valve cryopreserved in liquid nitrogen

目的探讨硫酸软骨素（CS）对液氮深低温冷冻保存的同种异体主动脉瓣的保护作用及机制。方法将48只兔主动脉瓣随机分成6组，每组8只瓣膜。其中新鲜组为新鲜主动脉瓣；对照组抗冻剂为二甲基亚砜（DM-SO），其体积百分比浓度为10%；实验Ⅰ~Ⅳ组内另含CS，其体积百分比浓度分别为2.5%、5%、7.5%、10%。采用阶段降温法进行深低温保存对照组和实验组主动脉瓣，复温后检测内皮细胞存活率，并行光镜及电镜检查。结果抗冻剂中含7.5%CS时，保存的瓣膜内皮细胞存活率最高，光镜及电镜下细胞的结构改变最轻，最接近新鲜主动脉瓣。结论CS能改善液氮深低温中保存的主动脉瓣内皮细胞活性，且这种保护作用与CS的体积百分比浓度有关，浓度为7.5%时效果最佳。

Objective To investigate the protective effect and the mechanism of chondrointin sulfate （CS） on cryopreserved homograft aortic valve in liquid nitrogen. Methods Fourty-eight rabbit aortic valves were randornly divided into 6 groups （ n = 8）. Eight fresh valves were included in fresh.group, the other 40 valves were cryopreserved in liquid nitrogen. Cryoprotectant for control group was 10% （volume） dimethyl sulfoxide （DM- SO） ,while cryoprotectant for experiment groups （ Ⅰ - Ⅳ ） contained different volume of CS （2.5%,5%, 7.5%, 10% ）with 10% DMSO,respectively. The survival rates of control group and experiment groups in 24 hours were examined and the specimens were observed under light and electron microscopes. Results Cryopreserved valves had the highest endothelial cell survival rates and the slightest morphologic change when 7.5 % CS was presented with 10% DMSO. Conclusion CS has protective effect on cryopreserved aortic valve in liquid nitrion,and the effect relates with the concentration of CS.The cryoprotectant with 7.5% CS shows the best effect.