A model for the initiation and growth of extracellular lipid
liposomes in arterial intima.
Yin, Yongyi, Kwang-Hee Lim, Sheldon Weinbaum, Shu Chien, and David S.
Rumschitzki.
Departments of Chemical Engineering and Mechanical Engineering,
City College of the City University of New York, Convent Avenue at
140th Street, New York, New York 10031 and Department of
Bioengineering, University of California, San Diego, La Jolla,
California 92093
APStracts 3:0340H, 1996.
There is considerable evidence that lumen lipoprotein cholesterol,
after crossing the arterial endothelium and entering the intima from
the vascular lumen, lodges in extracellular lipid packets (labelled
"liposomes") bound to extracellular matrix. These liposomes
appear to form by occasional attachment of an LDL to intimal matrix
and to grow in place mainly by appending available free LDL. The
liposome size distributions observed in chronically
hypercholesteremic (WHHL) and in short-term cholesterol-fed rabbits
are quite different. We propose a hierarchy of simple nucleation
-polymerization models to describe liposome formation and growth. Even
the simplest of these (with only one adjustable parameter) agrees
extremely well with the WHHL data. In contrast, the cholesterol-fed
rabbit data seem to result from the short-term, non-uniform intimal
history of LDL supply which is a consequence of the focal nature of
the transendothelial LDL flow through isolated, transient leaky
junctions. The same models used for the WHHL data, together with this
intimal nonuniformity, superimposed upon a slow, uniform
transendothelial seepage also account for this cholesterol-fed rabbit
data very well.
Received 7 April 1995; accepted in final form 6 August 1996.
APS Manuscript Number H341-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996