二甲基亚砜和1,2-丙二醇对深低温保存兔颈总动脉平滑肌细胞的影响

①目的 用二甲基亚砜(Me2SO)和1．2-丙二醇(PROH)深低温保存兔颈总动脉,评价两种保护剂对深低温保存复温后血管平滑肌细胞再生能力和超微结构的影响。②方法 将免颈总动脉用含有1.5mol／L的Me2SO或1．5mol／L PROH的低温保护剂深低温保存，并在冰袋中缓慢复温．新鲜血管作为对照。复温后和新鲜血管的平滑肌细胞进行体外培养，观察平滑肌细胞的再生能力;同时在透射电镜下观察平滑肌细胞的超微结构。③结果 体外培养结果显示，新鲜血管的平滑肌细胞体外培养24h后开始生长．PROH保存血管的平滑肌细胞在培养24～36h后开始生长；Me2SO保存血管的平滑肌细胞体外培养36～48h开始生长．而且再生细胞的数目显著少于前者，生长速度慢。透射电镜下，与新鲜血管的平滑肌细胞相比．PROH或Me2SO冷冻保存后血管的平滑肌细胞的线粒体等细胞器均无显著变化。但是Me2SO保存血管的平滑肌细胞核染色质的电子密度发生显著变化，异染色质的电子密度明显降低，与新鲜或PROH深低温保存血管平滑肌细咆核常染色质的低电子密度和异染色质的高电子密度明显不同。④结论 1.5mol／L PROH能够有效地保持平滑肌细胞的活性．并且对细胞的再生能力没有明显的损伤作用。Me2SO损伤平滑肌细胞的再生能力、同时引起平滑肌细胞核染色质超做结构的变化。

THE EFFECTS OF DIMETHYL SULFOXIDE AND 1,2-PROPANEDIOL ON THE SMOOTH MUSCLE CELLS OF CRYOPRESERVED RABBIT CAROTIDS

Objective To assess the different regenerative capabilities and ultrastructures of the smooth muscle cells(SMCs) of the cryopreserved rabbit carotids with dimethyl sulfoxide (Me_2SO) and 1,2-propanediol (PROH). Methods Rabbit carotids were cryopreserved in cryoprotective medium containing 1.5 mol/L PROH or 1.5 mol/L Me_2SO, and thawed slowly in ice bags. The fresh and thawed carotids were cultured in vitro and the regeneration of the SMCs observed. The ultrastructures of the SMCs in both fresh and thawed rabbit carotids were also investigated under transmission electron microscope (TEM). Results It took a little longer time (24-36 hours) for the SMCs of carotids cryopreserved with PROH than that of the fresh carotids (24 hours) to begin to regenerate in vitro. Meanwhile, it took 36-48 hours for the SMCs of carotids cryopreserved with Me_2SO, and the number of the renewed SMCs was obviously fewer than that of fresh carotids or those cryopreserved with PROH. Under TEM, the SMCs of thawed carotids, whether cryopreserved with PROH or Me_2SO, exhibited no obvious changes in their organelles. In the SMCs of the carotids cryopreserved with Me_2SO, the heterochromatin(Hch) that was normally of high electronic density in the SMCs of fresh carotids or those cryopreserved with PROH represented low electronic density as the euchromatin(Ech). Conclusion The SMCs of the rabbit carotids cryopreserved with 1.5 mol/L PROH maintained their viability without obvious damage to their regenerative abilities, while that cryopreserved with 1.5 mol/L Me_2SO decreased and obvious changes occurred in the chromatin architectures of the SMCs.