AJP - Heart and Circulatory Physiology, Vol 272, Issue 5 2188-H2194, Copyright © 1997 by American Physiological Society
Factors inducing codistribution of marginal actin fibers and fibronectin in rat aortic endothelial cells
K. Sugimoto, S. Fujii, T. Takemasa and K. Yamashita
Department of Anatomy, Nippon Medical School, Tokyo, Japan.
Rat endothelial cells have a unique arrangement of actin fibers running
with subendothelial fibronectin along the cell margins. The present study
was conducted to identify the factors that are associated with
codistribution of these actin fibers and fibronectin in fetal rat aortic
endothelial cells, mainly using rheological techniques. Fluorescence
histochemistry revealed that the codistribution pattern was established
between gestational days 14 and 15. The endothelial cells changed from
polygonal to spindle shaped during this gestational period. Although the
aortic length remained almost unchanged during this period of gestation,
both the diameter and expansion ratio of the aorta increased, by 9 and 10%,
respectively. On the other hand, the wall shear rate increased rapidly
during gestational days 13-16. These results indicate that the
codistribution of actin fibers and subendothelial fibronectin along the
margins of endothelial cells in fetal rat aorta occurs in association with
a rise in stretch and shear stress and that the endothelial cells may
require this change to maintain structural integrity.
