Role of platelet glycoprotein IIb/IIIa in ADP-activated platelet adhesion to aortic endothelial cells in vitro: observation with video-enhanced contrast microscopy.
Intravascular thrombus formation downstream of cerebral arterial occlusion may result in necrosis of ischemic tissue. To clarify the causative mechanisms, interaction between adenosine-5'-diphosphate (ADP)-activated platelets and cultured human aortic endothelial cells (HAEC) was examined by employing video enhanced contrast-differential interference contrast (VEC-DIC) microscopy. The numbers of (1) control/platelets, (2) ADP-activated platelets, (3) ADP-activated, anti-platelet GP Ibalpha antibody (GUR20-5)-treated platelets, and (4) ADP-activated, platelet GP IIb/IIa antagonist (TAK-029)-treated platelets, associated with HAEC after superfusion and wash-out were counted in visual fields of 30 x 30 microm2. Many ADP-activated platelets adhered to HAEC directly, while almost no platelets adhered to HAEC in the control. The adhesion was almost completely blocked by the GP IIb/IIIa antagonist, but not by GP Ibalpha antibody. We conclude that initial binding of ADP-activated platelets to HAEC is mediated by platelet GP IIb/IIIa in this in vitro system.
Tomita
Y
Y
Department of Neurology, Keio University School of Medicine, Tokyo, Japan. y-tomita@med.keio.ac.jp
Tanahashi
N
N
Tomita
M
M
Itoh
Y
Y
Yokoyama
M
M
Takeda
H
H
Schiszler
I
I
Fukuuchi
Y
Y
D000244:Adenosine Diphosphate / Q000502:physiology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D018715:Microscopy, Video; D010973:Platelet Adhesiveness / Q000502:physiology*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000502:physiology*
D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D000244:Adenosine Diphosphate