T. Sugiyama et al., LOSS OF ARTERIAL DILATION IN THE REENDOTHELIALIZED AREA OF THE FLOW-LOADED RAT COMMON CAROTID-ARTERY, Arteriosclerosis, thrombosis, and vascular biology, 17(11), 1997, pp. 3083-3091
We have investigated regenerated endothelial cells and their possible
contribution to arterial dilation in response to increased blood flow
in rat common carotid artery (CCA). After endothelial denudation using
a balloon catheter in the left CCA, an arteriovenous shunt was constr
ucted between the left CCA and the left external jugular vein at 20 mm
distal from the orifice in the denuded group. Animals that were given
the arteriovenous shunt without denudation were used to form the nond
enuded group. The blood flow rate in the left CCA was increased by six
fold after operation in the denuded group. We observed that endothelia
l cells were gradually regenerated from the orifice to the distal area
and that the reendothelialized area after 4 to 8 weeks was approximat
ely one third of the left CCA (5.31+/-1.49 mm at 4 weeks, 5.47+/-1.56
mm at 8 weeks). In the reendothelialized area of the left CCA after 4
to 8 weeks, the lumen diameter was significantly smaller than that of
the nondenuded group and showed no significant difference from age-mat
ched nonsurgical animals. The intimal and medial thickening, which wou
ld result in arterial stenosis in the reendothelialized area, was not
observed in the denuded group, although the denuded control showed sig
nificant intimal thickening. From these results, we conclude that rege
nerated endothelial cells reduce intimal thickening but do not respond
to increased blood flow to dilate the artery.