Aortas of male rabbits (2.0 to 2.5 kg body weight) were denuded of endothelium with a 4F balloon catheter and killed 7,14,60,90, and 180 days later. Aortic endotheiiai cell regrowth was determined using Evans blue dye and scanning electron microscopy. Early endotheiiai outgrowth was rapid, but by 14 days the regrowth slowed markedly so that no further increase of endotheiiai outgrowth was detected at other time periods. Another group of animals received 3 H-thymidine 1 hour before death and were killed 4,14, and 42 days later. The endotheiiai cell replication in the aortas of these animals was measured from Hautchen preparations. Endotheiiai cell replication was observed 4 days after balloon injury but was markedly reduced by 14 and 42 days. Intimal smooth muscle cell replication, however, was observed at both these later times. These results demonstrate that in vivo endotheiiai cell replication stops long before the aorta is repopulated and suggest that some mechanism other than contact between endotheiiai cells can prevent endotheiiai cell replication.
Arteriosclerosis – Wolters Kluwer Health
Published: May 1, 1982