Effect of thrombin inhibition on platelet deposition and thrombus formation at arteriolar shear
| Group . | Platelet deposition (in the 1st min after injury) Number of platelets/min . | Platelet deposition (3-5 min after injury) Number of platelets/min . | Time required for formation of the first thrombus (> 20 μm) (min) . | Mean vessel occlusion time* (min) . |
|---|---|---|---|---|
| Wild type† (n = 16) | 19.8 ± 4.6 | 54.2 ± 7.1 | 7.5 ± 1.1 | 19.2 ± 2.5 |
| Wild type + hirudin (n = 11) | 27.8 ± 5.7 | 33.5 ± 5.4 | 19.5 ± 2.1 | 39.6 ± 0.4 |
| P | P = .3 | P < .05 | P < .0001 | P < .0001 |
| Group . | Platelet deposition (in the 1st min after injury) Number of platelets/min . | Platelet deposition (3-5 min after injury) Number of platelets/min . | Time required for formation of the first thrombus (> 20 μm) (min) . | Mean vessel occlusion time* (min) . |
|---|---|---|---|---|
| Wild type† (n = 16) | 19.8 ± 4.6 | 54.2 ± 7.1 | 7.5 ± 1.1 | 19.2 ± 2.5 |
| Wild type + hirudin (n = 11) | 27.8 ± 5.7 | 33.5 ± 5.4 | 19.5 ± 2.1 | 39.6 ± 0.4 |
| P | P = .3 | P < .05 | P < .0001 | P < .0001 |
Mesenteric arterioles from hirudin-treated mice were explored and monitored as described in “Materials and methods.” Although no inhibition has been observed in the first minute, significantly less platelet adhesion to the vessel was found between 3 and 5 minutes after injury. The thrombus initiation and vessel occlusion were also dramatically inhibited by hirudin.
If vessel did not occlude, the end time of observation (40 min) was used.
Some of the wild-type results are also shown in Figure 1.