Selected parameters and characteristics of platelet interaction with immobilized VWF
Condition . | Velocity, μm/second . | Arrest time, seconds . | α/β Ca++ peaks, % . | γ Ca++ peaks, % . |
|---|---|---|---|---|
| Control | 1.90 ± 0.3 | 5.93 ± 2.82 | 20.05 ± 1.81 | 1.56 ± 0.5 |
| Apyrase (degrades ADP) | 2.40 ± 0.4 | 5.70 ± 2.51 | No effect | 0 |
| MRS2216 (inhibits P2Y1) | 5.50 ± 0.7* | 1.20 ± 0.82* | Partial inhibition | 0 |
| AR-C69931MX (inhibits P2Y12) | 2.16 ± 0.4 | 5.29 ± 0.32 | No effect | No effect |
| Wortmannin (inhibits PI 3-K) | ||||
| 10 nM | 2.20 ± 0.3 | 5.50 ± 2.21 | No effect | 0 |
| 100 nM | 2.90 ± 0.3† | 5.21 ± 0.23 | No effect | 0 |
| LY294002 (inhibits PI 3-K) | ||||
| 12.5 μM | 3.80 ± 0.6† | 2.56 ± 1.52† | No effect | 0 |
| 25.0 μM | 5.95 ± 0.5* | 0.96 ± 0.55* | No effect | 0 |
| U73122 (inhibits phospholipase C) | 6.50 ± 0.8* | 1.10 ± 1.25* | Partial inhibition | 0 |
| PP2 (inhibits Src-family kinases) | 5.80 ± 0.9* | 1.01 ± 0.64* | 0 | 0 |
| PGE1 (increases intracellular cAMP) | 5.85 ± 0.8* | 0.98 ± 0.52* | 0 | 0 |
| ASA (inhibits cyclooxygenase-1) | 2.15 ± 0.3 | 6.31 ± 0.94 | No effect | No effect |
Condition . | Velocity, μm/second . | Arrest time, seconds . | α/β Ca++ peaks, % . | γ Ca++ peaks, % . |
|---|---|---|---|---|
| Control | 1.90 ± 0.3 | 5.93 ± 2.82 | 20.05 ± 1.81 | 1.56 ± 0.5 |
| Apyrase (degrades ADP) | 2.40 ± 0.4 | 5.70 ± 2.51 | No effect | 0 |
| MRS2216 (inhibits P2Y1) | 5.50 ± 0.7* | 1.20 ± 0.82* | Partial inhibition | 0 |
| AR-C69931MX (inhibits P2Y12) | 2.16 ± 0.4 | 5.29 ± 0.32 | No effect | No effect |
| Wortmannin (inhibits PI 3-K) | ||||
| 10 nM | 2.20 ± 0.3 | 5.50 ± 2.21 | No effect | 0 |
| 100 nM | 2.90 ± 0.3† | 5.21 ± 0.23 | No effect | 0 |
| LY294002 (inhibits PI 3-K) | ||||
| 12.5 μM | 3.80 ± 0.6† | 2.56 ± 1.52† | No effect | 0 |
| 25.0 μM | 5.95 ± 0.5* | 0.96 ± 0.55* | No effect | 0 |
| U73122 (inhibits phospholipase C) | 6.50 ± 0.8* | 1.10 ± 1.25* | Partial inhibition | 0 |
| PP2 (inhibits Src-family kinases) | 5.80 ± 0.9* | 1.01 ± 0.64* | 0 | 0 |
| PGE1 (increases intracellular cAMP) | 5.85 ± 0.8* | 0.98 ± 0.52* | 0 | 0 |
| ASA (inhibits cyclooxygenase-1) | 2.15 ± 0.3 | 6.31 ± 0.94 | No effect | No effect |
Results were obtained by using the perfusion conditions described in the legend to Figure 2 with a wall shear rate of 3000 s-1. The concentrations of the various agents used are reported in the legends to Figure 1 and Figure 2, except for PP2 that was used at 25 μM. The values shown are the mean plus or minus the 95% confidence intervals. Between 180 and 250 platelets were examined in at least 3 separate experiments. The frequency of the different types of [Ca++]i peaks were expressed as percentage of platelets showing at least one Ca++ oscillation of a given type relative to the total number analyzed in the field of view during a 30-second observation period.
P < .01.
P < .05.