Tedgui A, Lever M J
Physiological Flow Studies Unit, Imperial College, London, United Kingdom.
Am J Physiol. 1987 Dec;253(6 Pt 2):H1530-9. doi: 10.1152/ajpheart.1987.253.6.H1530.
To measure the distribution volume for sucrose and albumin in the media of the rabbit thoracic aorta, we studied the uptake of tracers in vitro. In most cases the tracers were applied to both luminal and adventitial surfaces at the same concentration. When transmural convection was prevented by pressurization of the arteries with air, there was a decrease in sucrose space (19% at 70 mmHg and 28% at 180 mmHg) and in albumin space (60% at 70 mmHg and 66% at 180 mmHg), compared with the respective spaces in relaxed arteries (0.42 for sucrose and 0.08 for albumin). Much smaller changes were found when intact vessels were pressurized with liquid (insignificant for sucrose, decreases of 24% at 70 mmHg and 14% at 180 mmHg for albumin). Removal of the endothelium, which increases transmural fluid flux, increased the space for sucrose (not significantly at 70 mmHg and 17% at 180 mmHg) and particularly for albumin (100% at 70 mmHg and 250% at 180 mmHg). We conclude that the interstitial volume and consequently the protein space within the media can be modified both by distending stresses applied to the vessel and by transmural fluid flux.
为了测量兔胸主动脉中蔗糖和白蛋白在血管壁中层介质中的分布容积，我们在体外研究了示踪剂的摄取情况。在大多数情况下，将示踪剂以相同浓度施加于管腔和外膜表面。当通过向动脉内充空气加压来阻止跨壁对流时，与松弛动脉中的相应容积（蔗糖为0.42，白蛋白为0.08）相比，蔗糖分布容积（70 mmHg时降低19%，180 mmHg时降低28%）和白蛋白分布容积（70 mmHg时降低60%，180 mmHg时降低66%）均减小。当用液体对完整血管加压时，变化要小得多（蔗糖变化不显著，白蛋白在70 mmHg时降低24%，在180 mmHg时降低14%）。去除增加跨壁液体通量的内皮后，蔗糖分布容积增加（70 mmHg时增加不显著，180 mmHg时增加17%），尤其是白蛋白分布容积（70 mmHg时增加100%，180 mmHg时增加250%）。我们得出结论，血管壁中层的间质容积以及因此蛋白质分布容积可通过施加于血管的扩张应力和跨壁液体通量来改变。
