Role of thrombin in endothelial cell monolayer repair in vitro.
OBJECTIVE
We examined the effect of thrombin on human iliac artery endothelial cell monolayer repair and proliferation after denuding vascular injury.


METHODS
Human iliac artery endothelial cell monolayer repair was determined by scrape wounding confluent monolayers and measuring the advancement of the cells into the wounded area for 3 days. Proliferation studies involved plating human iliac artery endothelial cells at one tenth confluence and counting the increase in cell number every 2 days for a 2-week period. Proliferation during monolayer repair was examined by determining bromodeoxyuridine uptake in cells located at the leading edge of a scrape-wounded monolayer.


RESULTS
Thrombin (1 to 8 U/ml) inhibited human iliac artery endothelial cell monolayer repair in a concentration-related, reversible manner. The effect was augmented by decreasing serum concentration and was independent of the presence of endothelial cell growth supplement. Inactivation of thrombin's proteolytic site with diisopropylfluorophosphate eliminated its effect on monolayer repair. Thrombin (0.5 to 8 U/ml) inhibited human iliac artery endothelial cell proliferation in a dose-related manner. This effect was augmented by decreasing serum concentration. Finally, thrombin (4 U/ml) inhibited the proliferative response of cells located at the leading edge of wounded monolayers compared with control groups.


CONCLUSIONS
Thrombin inhibits human arterial endothelial cell monolayer repair and proliferation after denuding vascular injury.
DiMuzio
P J
PJ
Department of Surgery, Jefferson Medical College, Philadelphia.
Pratt
K J
KJ
Park
P K
PK
Carabasi
R A
RA
D002452:Cell Count; D002455:Cell Division; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000293:injuries / Q000473:pathology / Q000502:physiology; D006801:Humans; D007083:Iliac Artery / Q000187:drug effects* / Q000293:injuries / Q000473:pathology / Q000502:physiology; D007531:Isoflurophate / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology*
D016228:Endothelial Growth Factors; D007531:Isoflurophate; D013917:Thrombin