血流切应力变化对血管壁平滑肌细胞合成胶原的影响

Effects of the change of hemodynamic shear forces on smooth muscle cells collagen synthesis on the vessel wall

目的:观察血流切应力变化对血管壁胶原含量的影响,以探讨循环血管局部血流环境变化对血管结构的影响。方法:体外培养内皮细胞(EC)和平滑肌细胞(SMC),建立平行平板流动腔模型模拟产生切应力作用于EC,测定不同大小切应力作用后的内皮细胞条件培养液(EC-CM)中SMC的胶原合成量。结果:在0,0.10,0.15,0.25mN/cm2切应力作用后的EC-CM中培养24h后,每103SMC合成2,3-3H-羟脯氨酸的量分别为(1.31±0.123),(0.844±0.081),(0.609±0.099),(0.466±0.067)Bq;分泌的胶原量分别为(0.147±0.015),(0.101±0.026),(0.077±0.010),(0.041±0.004)Bq。结论:在生理范围内,随所受切应力的减小,EC-CM中SMC的胶原合成增加,提示血管局部血流速度的减缓使血管壁胶原沉积增多。

Objective: To gain the knowlege whether the changes of local blood flow affect the structure of vessel wall. Methods: The effects of culture medium conditioned with endothelial cells (EC) exposed to hemodynamic shear forces on modulation of smooth muscle cells (SMC) collagen synthesis in the arterial wall was investigated. Endothelial and SMC were isolated and cultured in vitro . The parallel plated flow chamber device was established to simulate blood flow environment. Supernatant of EC exposed to laminar flow was used to study collagen synthesis of SMC by 2,3 3H proline incorporation into 3H hydroxyproline. Results : After cultured in the culture medium conditioned with EC exposed to 0.25,0.15,0.10,0 mN/cm 2 shear stress for 24 h, the contents of 3H hydroxyproline incorporated into SMC was (1.31±0 123), (0 844±0 081), (0 609±0 099), (0.466±0.067) Bq per 10 3 cells, and the contents of 3H hydroxyproline secreted into culture medium was (0.147±0.015), (0.101±0.026), (0.077±0.010), (0.041±0 004) Bq per 10 3 cells. Conclusion: The results suggest that the reduction of local blood flow might stimulate accumulation of vascular collagen.