Perturbation of platelet adhesion to endothelial cells by plasminogen activation in vitro.
To investigate whether the endothelium-platelet interactions may be altered by plasminogen activation, cultured human umbilical vein endothelial cells (ECs) were treated with tissue-type plasminogen activator (t-PA) in the presence of plasminogen, and platelet adhesion to ECs was subsequently measured by using a tapered flow chamber. Our results demonstrated that platelets adhered more readily to t-PA treated EC monolayer than to the control monolayer at all shear stress levels tested. This phenomenon was treatment time-dependent and dose-dependent, and it could be blocked by adding plasmin inhibitors, such as epsilon-amino caproic acid and aprotinin. Adherent platelets on t-PA treated EC monolayer underwent more severe shape change than those on the control monolayer. While the extracellular matrix directly treated with t-PA attracted less platelets than the control matrix did, platelet adhesion to the matrix that was produced by t-PA-treated ECs was unaltered. These data suggest that t-PA treatment on ECs compromised antiplatelet-adhesion capability on their apical surface without altering the reactivity of their extracellular matrix towards platelets.
Chen
H
H
Department of Physiology, National Cheng-Kung University, Tainan, Taiwan, ROC.
Wu
Y I
YI
Hsieh
Y L
YL
Shi
G Y
GY
Jiang
M J
MJ
Chang
W C
WC
Chuang
W J
WJ
Kan
W M
WM
Tang
M J
MJ
Jen
C J
CJ
D001792:Blood Platelets / Q000166:cytology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology*; D006801:Humans; D010958:Plasminogen / Q000502:physiology*; D010960:Plasminogen Activators / Q000494:pharmacology*; D010959:Tissue Plasminogen Activator / Q000494:pharmacology*
D010958:Plasminogen; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator