低切应力对体外培养动脉形态学重建的影响

EFFECTS OF LOW SHEAR STRESS ON MORPHOLOGICALREMODELING IN ORGAN-CULTURED ARTERY IN VITRO

目的 研究低切应力对血管的生物学作用 ,探讨切应力与血管形态学重建的关系。 方法 采用血管体外应力培养系统 ,培养猪颈总动脉 ,通过组织学、免疫组织化学和图像分析等方法 ,探讨低切应力作用下动脉重建的形态学改变。 结果 切应力减小时 ,动脉发生显著的结构重建 ,其特征为管径缩小 ,壁面积减小 ,管壁增厚 ,壁厚 内径比增加 ;低切应力作用使动脉部分中膜VSMC由收缩型转变为合成型 ,表现为α 肌动蛋白含量下降 ,细胞核朝向改变 ,发生扭曲 ,变大变圆 ,核仁明显。 结论 低切应力和血压改变所致的血管重建在形态学方面有很大不同 ,提示 :切应力和血压改变对血管重建的作用机制不同 ;中膜VSMC的表型转换是低切应力引起血管重建的基础。

Objective To explore the biological effects of low shear stress on artery and the relationship between stress and vascular remodeling. Methods The common carotid arteries of pigs were cultured in the artery organ culture system under low shear stress in vitro.Morphological changes in the arteries were studied with morphological,immunohistochemical and computer image processing methods. Results The cultured artery remodeling occurred obviously under low shear stress,expressed as decreasing of inner diameter and wall area while wall thickness and ratio of wall thickness to inner diameter increased.Some VSMC changed from contractile phenotype to synthetic phenotype under low shear stress.The relative area of α-actin decreased,nucleus became twisted,bigger and rounder,array complicatedly,and nucleoli can be obviously observed in VSMC.Conclusion The vascular remodeling as a result of the low shear stress is different from that of the alteration of pressure in the morphological chages,which suggested that they have different mechanism.Phenotype switch of VSMC is the base of vascular remodeling under low shear stress.;