Chien S, Lee M M, Laufer L S, Handley D A, Weinbaum S, Caro C G, Usami S
Arteriosclerosis. 1981 Sep-Oct;1(5):326-36. doi: 10.1161/01.atv.1.5.326.
Transport of 125I-albumin by isolated segments of canine common carotid arteries was studied in vitro at zero transmural pressure. Sinusoidal oscillatory variations in length (peak change 4%) for 15 minutes at frequencies of 5 and 10 Hz caused 40% increase in 125I-albumin uptake, and also a 30% increase in the apparent luminal surface area. Changes in the duration and frequency of oscillation indicate that the total number of oscillations (= frequency X duration) was the critical parameter in causing these effects. The increase in apparent luminal surface area was correlated with regional flattening of the internal elastic lamina and the overlying endothelial cells, as demonstrated by transmission and scanning electron microscopy. Endothelial vesicles were counted with the aid of ruthenium red as a postfixation extracellular marker. The ratio of unstained free vesicles to total vesicles averaged 0.083 in the control state and decreased slightly to 0.070 after oscillation. Although the decrease in free vesicle population indicated an acceleration of vesicle diffusion, our theoretical computations showed that the resulting increase in vesicle flux was negligible. The increase in 125I-albumin uptake by the artery following mechanical oscillation is mainly attributable to the increase in apparent luminal surface area.
在体外零跨壁压力条件下，研究了犬颈总动脉分离段对125I - 白蛋白的转运。在5赫兹和10赫兹频率下，15分钟内长度呈正弦振荡变化（峰值变化4%），导致125I - 白蛋白摄取增加40%，同时管腔表面积明显增加30%。振荡持续时间和频率的变化表明，振荡总数（=频率×持续时间）是产生这些效应的关键参数。如透射电镜和扫描电镜所示，管腔表面积的增加与内弹性膜和覆盖其上的内皮细胞的局部变平相关。借助钌红作为固定后细胞外标记物对内皮小泡进行计数。在对照状态下，未染色的游离小泡与总小泡的比率平均为0.083，振荡后略有下降至0.070。尽管游离小泡数量的减少表明小泡扩散加速，但我们的理论计算表明，由此导致的小泡通量增加可忽略不计。机械振荡后动脉对125I - 白蛋白摄取的增加主要归因于管腔表面积的增加。
