AJP - Heart and Circulatory Physiology, Vol 253, Issue 6 1530-H1539, Copyright © 1987 by American Physiological Society
Effect of pressure and intimal damage on 131I-albumin and [14C]sucrose spaces in aorta
A. Tedgui and M. J. Lever
Physiological Flow Studies Unit, Imperial College, London, United Kingdom.
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.
