ISSN:
1432-0878
Keywords:
Aortic endothelium, mouse
;
Macromolecular transport
;
Horseradish peroxidase
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Aortic endothelium presents a continuous barrier to diffusion of macromolecules. The cell margins overlap for long distances and there are multiple points of contact between the cell membranes at which the intercellular cleft is reduced to 30–40 Å or less, and free diffusion of lanthanum is impeded at some points of apposition. Macromolecular transport through the endothelium of mouse aorta was studied with the help of horseradish peroxidase (HRP) and bovine milk lactoperoxidase. Following injection of 0.25–0.5 mg of HRP no tracer was detected in the intercellular clefts even though it was seen in plasmalemmal vesicles and subendothelial space. However, when 5 mg of HRP was injected in either 0.05 or 0.5 ml of saline, transport of the enzyme occurred through both the intercellular clefts and via the plasmalemmal vesicles. On the other hand, lactoperoxidase of m.w. 82000 was transported through the plasmalemmal vesicles only. The findings were discussed with reference to the transport of serum lipoproteins and it was suggested that low and high density lipoproteins would be transported via the plasmalemmal vesicles.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00307143
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