The effects of shear stress on endothelial cell retention and function on expanded polytetrafluoroethylene
H. P. Greisler, S. Johnson, K. Joyce, S. Henderson, N. M. Patel, T. Alkhamis, R. Beissinger and D. U. Kim
Department of Surgery, Loyola University Medical Center, Maywood, Ill. 60153.
We evaluated the adherence of indium 111-radiolabeled endothelial cells to
fibronectin-treated expanded polytetrafluoroethylene surfaces exposed to
high (437 s-1) vs low (218 s-1) shear and the influence of shear on
prostacyclin production. Canine jugular vein factor VIII-positive
endothelial cells in passages 3 through 6 were incubated with
111Indium-oxine, and labeled cells were seeded onto fibronectin-treated
expanded polytetrafluoroethylene patches. Patches with confluent cells were
exposed to shear in a Weissenberg rheogoniometer for intervals ranging up
to 60 minutes. Percent endothelial cell retention was determined by gamma
counting of patches and media and by histologic evaluation. Prostacyclin
production (tritiated radioimmunoassay of 6-keto-prostaglandin F1 alpha)
was assayed on perfusing media. Results showed no differences in
6-keto-prostaglandin F1 alpha production between shear rates or time
periods. Endothelial cell retention did not differ between the shear rates.
Rotational shear caused persistent cell loss over time in either high- or
low-shear conditions. This persistent cell loss in response to steady
rotational shear differs from that in response to identical rates of
pulsatile linear shear in our laboratory where cell loss approached zero
after 15 minutes.
