ADP-stimulated binding of fibrinogen and VWF to human, murine, and mmHH platelets and inhibition by RGDS and tirofiban
| . | Human platelets . | Murine platelets . | mmHH platelets* . |
|---|---|---|---|
| Ligand binding (Kd, nM) | |||
| Fibrinogen | 66.5 ± 3.2 | 67.1 ± 2.8 | ND |
| VWF | 20.6 ± 2.8 | 25.6 ± 3.1 | ND |
| IC50 for fibrinogen binding | |||
| RGDS, μM | 3.5 ± 1.6 | 35.9 ± 7.1 | 2.3 ± 0.2 |
| Tirofiban, nM | 0.9 ± 0.2 | 1.6 ± 0.9 | 1.3 ± 0.3 |
| IC50 for VWF binding | |||
| RGDS, μM | 21.0 ± 1.2 | 68.6 ± 20.8 | 14.4 ± 10.3 |
| Tirofiban, nM | 1.2 ± 0.4 | 2.0 ± 1.0 | 1.5 ± 0.2 |
| . | Human platelets . | Murine platelets . | mmHH platelets* . |
|---|---|---|---|
| Ligand binding (Kd, nM) | |||
| Fibrinogen | 66.5 ± 3.2 | 67.1 ± 2.8 | ND |
| VWF | 20.6 ± 2.8 | 25.6 ± 3.1 | ND |
| IC50 for fibrinogen binding | |||
| RGDS, μM | 3.5 ± 1.6 | 35.9 ± 7.1 | 2.3 ± 0.2 |
| Tirofiban, nM | 0.9 ± 0.2 | 1.6 ± 0.9 | 1.3 ± 0.3 |
| IC50 for VWF binding | |||
| RGDS, μM | 21.0 ± 1.2 | 68.6 ± 20.8 | 14.4 ± 10.3 |
| Tirofiban, nM | 1.2 ± 0.4 | 2.0 ± 1.0 | 1.5 ± 0.2 |
Values are the mean and 1 SE of 3 experiments.
ND indicates not done.
Transgenic mice are homozygous for a disabled murine αIIb gene and express a human αIIb transgene at a level approaching that of human platelets.27