Transport of /sup 125/I-albumin across normal and deendothelialized rabbit thoracic aorta in vivo

Journal Article · · Arteriosclerosis (Dallas); (United States)

OSTI ID:6905920

Ramirez, C A; Colton, C K; Smith, K A; Stemerman, M B; Lees, R S

Transmural concentration profiles of /sup 125/I-albumin in vivo were measured across the normal and balloon catheter-deendothelialized rabbit descending thoracic aorta as a function of time following intravenous injection. A tracer was injected 5 or 60 minutes after deendothelialization, and the animals were sacrificed after circulation times of 10, 30 or 60 minutes. The aorta was immediately excised and frozen flat between glass slides. Samples were serially sectioned parallel to the intimal surface in a refrigerated microtome, washed with trichloroacetic acid (TCA), and counted. Relative tissue concentration profiles of TCA-precipitable radioactivity from the media of control animals showed entry from both luminal and adventitial sides, as previously found with conscious normal rabbits, but spatial gradients at both luminal and medial-adventitial borders were less steep. Relative concentration levels in ballooned animals were 10- to 40-fold higher than in controls, and the profiles were flatter. Uptake rates at equivalent circulation times were greater in experiments initiated 60 minutes, as compared with 5 minutes, after deendothelialization, suggesting that progressive medial edema may have occurred following balloon injury. These results show that the intact endothelium is the dominant mass transfer resistance for /sup 125/I-albumin transport across the aortic wall. The data also suggest that the incomplete monolayer of platelets adherent to the subendothelium after balloon deendothelialization is not a substantial resistance to transport, as compared to that of the media, and that convection plays a more important role than diffusion for /sup 125/I-albumin transport across the deendothelialized aortic wall.

• Research Organization: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge
• OSTI ID: 6905920
• Journal Information: Arteriosclerosis (Dallas); (United States), Journal Name: Arteriosclerosis (Dallas); (United States) Vol. 4:3; ISSN ARTRD
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
ANIMALS
AORTA
ARTERIES
BETA DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HISTOLOGICAL TECHNIQUES
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
INTRAVENOUS INJECTION
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RABBITS
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES