Chien S, Fan F, Lee M M, Handley D A
Biorheology. 1984;21(4):631-41. doi: 10.3233/bir-1984-21420.
The effects of variations in transmural pressure over a range of 0 to 200 mmHg on transendothelial transport of macromolecules were studied in the canine common carotid artery. The uptake of 125I-albumin per unit artery weight increased with rising pressure. There was no significant difference in albumin permeability per unit luminal surface area between 0 and 100 mmHg, but permeability nearly doubled when pressure was raised to 200 mmHg. The contribution of an increased rate of transendothelial vesicle diffusion, as evaluated from the experimental determination of the ratio of attached-to-free vesicles and theoretical modeling, was found to be negligible. The reduction in transendothelial vesicle diffusion distance due to pressure-induced thinning of the peripheral zone contributes to a 25% increase in permeability. With the use of colloidal Ag and Au of various sizes, vesicle loading of particles with diameters greater than or equal to 15 nm was found to be severely restricted at transmural pressure less than or equal to 100 mmHg, but it was significantly enhanced at 200 mmHg, when particles as large as 25 nm became detectable in endothelial vesicles and subendothelial space. This hypertension-induced increase in macromolecular transport across the endothelium may cause an overloading of the arterial wall with low-density lipoproteins and play a significant role in atherogenesis.
在犬类颈总动脉中研究了0至200 mmHg范围内跨壁压力变化对大分子经内皮转运的影响。单位动脉重量对125I-白蛋白的摄取量随压力升高而增加。在0至100 mmHg之间，单位管腔表面积的白蛋白通透性无显著差异，但当压力升至200 mmHg时，通透性几乎增加了一倍。根据附着囊泡与游离囊泡比例的实验测定和理论模型评估，经内皮囊泡扩散速率增加的贡献可忽略不计。由于压力导致外周区变薄，经内皮囊泡扩散距离缩短，这使得通透性增加了25%。使用各种大小的胶体银和金，发现直径大于或等于15 nm的颗粒在跨壁压力小于或等于100 mmHg时，囊泡对颗粒的负载受到严重限制，但在200 mmHg时显著增强，此时在内皮囊泡和内皮下间隙中可检测到直径达25 nm的颗粒。这种高血压诱导的大分子跨内皮转运增加可能导致动脉壁低密度脂蛋白过载，并在动脉粥样硬化形成中起重要作用。
