Characteristics of the 3 phases of clot contraction under different experimental conditions
| Compound or cells added . | Phase 1 . | Phase 2 . | Phase 3 . | |||||
|---|---|---|---|---|---|---|---|---|
| % Contraction . | Decay rate at t = 50 s %/s (×10−2) . | tt, s . | % Contraction . | k2, %/s (×10−2) . | t2, s . | % Contraction . | Decay rate at t = 750 s %/s (×10−2) . | |
| Effect of thrombin (n = 5) | ||||||||
| 1 U/mL | 6 ± 0.7 | 4.2 ± 0.7 | 98 | 10 ± 1.0 | 6.7 ± 0.5 | 278 | 35 ± 2.8 | 1.4 ± 0.1 |
| 0.5 U/mL | 6 ± 1.0 | 3.2 ± 0.7 | 103 | 2 ± 0.3*** | 5.2 ± 0.6 | 144 | 25 ± 1.0*** | 1.2 ± 0.3 |
| Blebbistatin (n = 3) | ||||||||
| 0 (control) | 4 ± 0.8 | 2.2 ± 0.8 | 90 | 10 ± 1.7 | 5.9 ± 1.0 | 270 | 28 ± 0.7 | 1.0 ± 0.08 |
| 25 µM | 5 ± 0.6 | 2.9 ± 0.4 | 150 | 5 ± 1.0** | 3.3 ± 0.7* | 300 | 18 ± 2.8** | 0.8 ± 0.1 |
| 50 µM | 4 ± 0.6 | 2.5 ± 0.4 | 97 | 6 ± 0.8* | 2.9 ± 0.4** | 315 | 15 ± 1.4*** | 0.7 ± 0.07* |
| 100 µM | 5 ± 1 | 3.1 ± 0.6 | 120 | 2 ± 0.2**** | 1.7 ± 0.2*** | 225 | 12 ± 1.6**** | 0.5 ± 0.06*** |
| Effect of cross-linking | ||||||||
| Control (n = 5) | 5 ± 1.1 | 2.6 ± 0.3 | 101 | 7 ± 0.7 | 5.3 ± 0.6 | 259 | 35 ± 0.7 | 0.7 ± 0.09 |
| Iodoacetamide (1 mM) (n = 5) | 10 ± 1.5* | 4.6 ± 1.1 | 225 | 6 ± 0.3 | 2.8 ± 0.1** | 458 | 18 ± 1.6*** | 0.7 ± 0.1 |
| Cystamine (0.5 mM) (n = 4) | 4 ± 0.6 | 2.3 ± 0.6 | 105 | 14 ± 3.0 | 4.0 ± 0.8 | 450 | 19 ± 5.0* | 0.8 ± 0.2 |
| Cystamine (2 mM) (n = 4) | 10 ± 2.8 | 5.3 ± 1.2 | 307 | 15 ± 3.0* | 1.6 ± 0.3** | NA | NA | NA |
| Platelets (n = 4) | ||||||||
| <150 k/µL | 2 ± 0.5 | 1.2 ± 0.4 | NA | NA | NA | NA | NA | NA |
| 250-300 k/µL | 9 ± 2.0*** | 5.7 ± 1.8** | 357 | NA | NA | NA | 7 ± 1.2 | 0.2 ± 0.03 |
| >500 k/µL | 17 ± 1.8***,+ | 10.5 ± 1.4*** | 357 | NA | NA | NA | 14 ± 1.8+ | 0.5 ± 0.06++ |
| RBCs (n > 4) | ||||||||
| <10% | NA | NA | NA | 15 ± 1.5 | 7.5 ± 0.8 | 240 | 52 ± 1.8 | 1.9 ± 0.07 |
| 15-20% | NA | NA | NA | 14 ± 2.6 | 5.2 ± 1.4 | 255 | 41 ± 3.8** | 1.4 ± 0.07** |
| 30-40% | NA | NA | NA | 12 ± 1.0 | 4.1 ± 0.9* | 232 | 43 ± 0.5** | 1.2 ± 0.09** |
| >40% | NA | NA | NA | 12 ± 2.5 | 3.4 ± 0.9* | 285 | 34 ± 1.0***,xxx | 1.1 ± 0.1** |
| Compound or cells added . | Phase 1 . | Phase 2 . | Phase 3 . | |||||
|---|---|---|---|---|---|---|---|---|
| % Contraction . | Decay rate at t = 50 s %/s (×10−2) . | tt, s . | % Contraction . | k2, %/s (×10−2) . | t2, s . | % Contraction . | Decay rate at t = 750 s %/s (×10−2) . | |
| Effect of thrombin (n = 5) | ||||||||
| 1 U/mL | 6 ± 0.7 | 4.2 ± 0.7 | 98 | 10 ± 1.0 | 6.7 ± 0.5 | 278 | 35 ± 2.8 | 1.4 ± 0.1 |
| 0.5 U/mL | 6 ± 1.0 | 3.2 ± 0.7 | 103 | 2 ± 0.3*** | 5.2 ± 0.6 | 144 | 25 ± 1.0*** | 1.2 ± 0.3 |
| Blebbistatin (n = 3) | ||||||||
| 0 (control) | 4 ± 0.8 | 2.2 ± 0.8 | 90 | 10 ± 1.7 | 5.9 ± 1.0 | 270 | 28 ± 0.7 | 1.0 ± 0.08 |
| 25 µM | 5 ± 0.6 | 2.9 ± 0.4 | 150 | 5 ± 1.0** | 3.3 ± 0.7* | 300 | 18 ± 2.8** | 0.8 ± 0.1 |
| 50 µM | 4 ± 0.6 | 2.5 ± 0.4 | 97 | 6 ± 0.8* | 2.9 ± 0.4** | 315 | 15 ± 1.4*** | 0.7 ± 0.07* |
| 100 µM | 5 ± 1 | 3.1 ± 0.6 | 120 | 2 ± 0.2**** | 1.7 ± 0.2*** | 225 | 12 ± 1.6**** | 0.5 ± 0.06*** |
| Effect of cross-linking | ||||||||
| Control (n = 5) | 5 ± 1.1 | 2.6 ± 0.3 | 101 | 7 ± 0.7 | 5.3 ± 0.6 | 259 | 35 ± 0.7 | 0.7 ± 0.09 |
| Iodoacetamide (1 mM) (n = 5) | 10 ± 1.5* | 4.6 ± 1.1 | 225 | 6 ± 0.3 | 2.8 ± 0.1** | 458 | 18 ± 1.6*** | 0.7 ± 0.1 |
| Cystamine (0.5 mM) (n = 4) | 4 ± 0.6 | 2.3 ± 0.6 | 105 | 14 ± 3.0 | 4.0 ± 0.8 | 450 | 19 ± 5.0* | 0.8 ± 0.2 |
| Cystamine (2 mM) (n = 4) | 10 ± 2.8 | 5.3 ± 1.2 | 307 | 15 ± 3.0* | 1.6 ± 0.3** | NA | NA | NA |
| Platelets (n = 4) | ||||||||
| <150 k/µL | 2 ± 0.5 | 1.2 ± 0.4 | NA | NA | NA | NA | NA | NA |
| 250-300 k/µL | 9 ± 2.0*** | 5.7 ± 1.8** | 357 | NA | NA | NA | 7 ± 1.2 | 0.2 ± 0.03 |
| >500 k/µL | 17 ± 1.8***,+ | 10.5 ± 1.4*** | 357 | NA | NA | NA | 14 ± 1.8+ | 0.5 ± 0.06++ |
| RBCs (n > 4) | ||||||||
| <10% | NA | NA | NA | 15 ± 1.5 | 7.5 ± 0.8 | 240 | 52 ± 1.8 | 1.9 ± 0.07 |
| 15-20% | NA | NA | NA | 14 ± 2.6 | 5.2 ± 1.4 | 255 | 41 ± 3.8** | 1.4 ± 0.07** |
| 30-40% | NA | NA | NA | 12 ± 1.0 | 4.1 ± 0.9* | 232 | 43 ± 0.5** | 1.2 ± 0.09** |
| >40% | NA | NA | NA | 12 ± 2.5 | 3.4 ± 0.9* | 285 | 34 ± 1.0***,xxx | 1.1 ± 0.1** |
Mean ± SEM. Note: RGDS and 200 μM blebbistatin abrogated the presence of different phases. * or +P < .05 when compared with control; ** or ++P < .01 when compared with control; *** or +++ or xxxP < .001 when compared with control, 250 000-300 000/μL platelets, or 30-40% hematocrit, respectively; **** or ++P < .0001 when compared with control.
NA, phase was not applicable for that sample.