深低温保存兔颈总动脉体外灌注后的结构和力学性能研究  

Structural and mechanical changes of cryopreserved rabbit carotids after reperfusion in vitro

作　　者：王沛涛[1] 刘忠强[1] 李强[1] 付秀艳[1] 李华琴[1] 

机构地区：[1]青岛大学医学院附属医院低温医学科,266003

出　　处：《中国医药生物技术》2007年第2期118-122,共5页Chinese Medicinal Biotechnology

摘　　要：目的 探讨深低温保存对动脉血管组织学和力学性能的影响.方法 取20只新西兰兔的颈总动脉,用含1.5 mol/L 1,2-丙二醇的低温保护剂深低温(-196℃)保存10～15 d,并在预冷的冰袋内缓慢复温;以新鲜血管作为对照.对新鲜和冷冻-复温血管的平滑肌细胞(SMC)进行体外培养,观察和分析新鲜、冷冻-复温和冷冻复温后体外灌注6、12和24 h血管的内皮细胞、SMC、血管壁组织构和力学性能(轴向、周向弹性模量和断裂应力)的变化.结果 冷冻-复温后血管的SMC在体外培养中开始生长时间与新鲜血管基本相同(24～36 h),生长速度接近.深低温保存后,血管内皮细胞数量减少,电镜观察SMC数量和形态无明显变化,但血管的轴向弹性模量(5.82±0.55)、轴向断裂应力(58.78±6.96)和周向弹性模量(1.44±0.22)、周向断裂应力(3.45±0.40)均明显低于新鲜血管(分别为6.45±0.80、146.96±23.60和1.83±0.17、5.33±0.50,P＜0.05或P＜0.01).体外灌注后,冷冻-复温血管的内皮细胞脱落,SMC变性、坏死,内弹力纤维和胶原出现不同程度崩裂,力学性能指标中除了轴向弹性模量外,均进一步降低(P＜0.05或P＜0.01).结论 兔颈总动脉SMC深低温保存效果满意,但体外灌注对经深低温保存血管的内皮细胞、SMC和血管壁结构具有明显损伤作用,导致血管力学性能显著降低.Objective To explore the effect of cryopreservation on the histology and mechanical properties of rabbit carotid artery. Mathods A total of 20 New Zealand rabbit carotids were harvested and cryopreserved in a cryoprotective medium containing 1.5 mol/L 1,2-propanediol (PROH) for 10-15 days, and then thawed slowly in an ice bag that had been precooled in liquid nitrogen. Fresh carotids were used as a control. The fresh and freeze-thawed arteries were cultured for the growth of vascular smooth muscle cells (VSMCs). The freeze-thawed arterial tissues were reperfused in vitro for 6, 12, or 24 hours, respectively, to assess the development of endothelial cells (ECs) and VSMCs, and integrity and mechanical properties of the carotid walls (elastic lamellae or fibers and elastic modulus and fracture strength). Results It took 24-36 hours for both the VSMCs of freeze-thawed and fresh arteries to regenerate. The growing speed of them was similar. After been cryopreserved, the amount of vascular ECs decreased; no changes of the amount and morphology of SMCs were observed under a electron microscope. However, the longitudinal elastic moduli, longitudinal fracture stress, circumferential elastic moduli, and circumferential fracture stress of the freeze-thawed rabbit carotids were significantly lower than those of the fresh vessels (5.82 ± 0.55, 58.78 ± 6.96, 1.44 ± 0.22, and 3.45 ± 0.40 vs. 6.45 ± 0.80, 146.96 ± 23.60, 1.83 ± 0.17, and 5.33 ± 0.50; P < 0.05 or P < 0.01). After in vitro reperfusion, all the survived ECs of the freeze-thawed carotids fell off, and some of the VSMCs denaturalized or necrosed; the internal elastic fibers and collagen showed various degrees of cracking, and their mechanical properties further decreased (P < 0.05). Conclusions The effect of cryopreservation of rabbit carotid VSMCs with PROH is satisfying. However, the freeze-thawing process and the following in vitro reperfusion bring obvious damage to the ECs, VSMCs, and the configuration of the artery wall, resulting in significant decreas

关 键 词：颈总动脉 低温保存 生物力学 再灌注 兔 

分 类 号：R318.52[医药卫生—生物医学工程]