Tedgui A, Lever M J
Circ Res. 1985 Dec;57(6):856-63. doi: 10.1161/01.res.57.6.856.
The interaction of convection and diffusion in the transport of 131I-labeled albumin within the wall of rabbit thoracic aorta was studied in vessels excised at in vivo length. They were pressurized with a solution containing no tracer and immersed in a solution containing labeled albumin. The label then entered the wall tissue via the adventitia and had to diffuse against the convective flux which occurred from the lumen to the adventitia. Experiments were performed on intact and deendothelialized vessels pressurized to 70 and 180 mm Hg. At the end of each experiment the vessels were subjected to sequential frozen sectioning parallel to the lumenal surface. The radioactivity of the 20-micron-thick sections was determined and expressed as a tissue:labeled solution concentration ratio. Transmural profiles of these ratios were thus obtained. The steady state was found to be achieved by about 90 minutes. When the convection was enhanced by removal of the endothelium, the average ratios were lower than when the endothelium was intact, and the profile was much flatter. The results suggest that convection influenced macromolecular transport within the arterial wall, even in vessels with intact endothelium.
在取自兔胸主动脉的、保持体内长度的离体血管中，研究了对流与扩散在131I标记白蛋白于血管壁内转运过程中的相互作用。用不含示踪剂的溶液对血管加压，然后将其浸入含有标记白蛋白的溶液中。标记物随后经外膜进入血管壁组织，并不得不逆着从管腔到外膜的对流通量进行扩散。对完整血管和去内皮血管进行了实验，血管压力分别为70和180 mmHg。在每个实验结束时，将血管进行与管腔表面平行的连续冰冻切片。测定20微米厚切片的放射性，并表示为组织：标记溶液浓度比。由此获得这些比值的跨壁分布图。发现约90分钟可达到稳态。当通过去除内皮增强对流时，平均比值低于内皮完整时，且分布图更平缓。结果表明，即使在内皮完整的血管中，对流也会影响大分子在动脉壁内的转运。
