中文摘要：

目的探讨降温速率对深低温保存兔颈总动脉力学性能、组织结构和生物活性的影响。方法取家兔双侧颈总动脉100根，均分为5组（n=20）。A组：新鲜家兔动脉作为对照组；B、C、D、E组分别以-0．5、-1、-2、-5℃／min的降温速率进行低温保存。对各组动脉力学性能、组织结构、生物学活性进行比较。结果低温保存动脉与对照组比较，其黏弹性均有损失；随降温速率的增加，其黏弹性损失趋于增加。B、D、E组与C组的生物活性差异有显著性（P〈0．05）。结论-0．5℃／min降温速率低温冷冻保存的血管参数最接近新鲜血管，是血管低温保存的最佳降温速率。

英文摘要：

Objective To estimate the influence of different cooling rate on the mechanics characteristics, organizational structure,biological activity of the cryopreservation rabbit carotids. Methods 100 rabbits＇ carotids were har-vested from 50 rabbits and randomly divided into fiver groups. A group was control, the B, C, D and E were frozen with the cooling rate of -0.5, -1,-2 and -5℃/min to -80℃,then frozen with -5℃/min to -130 ℃. Viscoelasticity, electron microscope, gradation, were used to determine the mechanics characteristics, organizational structure, biological activity. Results The results showed that the viscoelasticity of cryopreserved arteries was apparently less than that of the fresh group, the loss of viscoelasticity of the cryopreserved arteries increased along with the increase of cooling rates. The biological activity of C group was significantly different with B, D, E groups （P〈0.05）. Conclusion Cryopreservation causes the structural and functional 0.5 ℃/min may be the prefect method of cryopreservation. damage of arteries. The cooling rate of