Argatroban Inhibition of Thrombin Present in Aged Plasma Clots Lysed With Streptokinase or Alteplase
| Clot Age (h) . | Maximum Activity (mOD/min) . | IC50 (μmol/L) . | Maximum Inhibition (% control) . | Plasmin Activity (% control) . | No. of Donors . |
|---|---|---|---|---|---|
| A. Plasma clots—aged and lysed with streptokinase | |||||
| 3 | 51 ± 14 | 0.83 ± 0.15 | 70 ± 2 | 38 ± 11 | 3 |
| 6 | 61 ± 29 | 0.45 ± 0.23 | 71 ± 8 | 38 ± 0 | 2 |
| B. Plasma clots—aged and lysed with alteplase | |||||
| 3 | 98 ± 24 | 0.78 ± 0.11 | 74 ± 6 | 8 ± 2 | 2 |
| 6 | 81 ± 11 | 0.68 ± 0.11 | 70 ± 1 | 9 ± 1 | 2 |
| C. Control aged plasma clots | |||||
| 3 | 29 ± 13 | 0.64 ± 0.09 | 95 ± 4 | — | 4 |
| 6 | 22 ± 9 | 0.70 ± 0.15 | 94 ± 3 | — | 4 |
| Clot Age (h) . | Maximum Activity (mOD/min) . | IC50 (μmol/L) . | Maximum Inhibition (% control) . | Plasmin Activity (% control) . | No. of Donors . |
|---|---|---|---|---|---|
| A. Plasma clots—aged and lysed with streptokinase | |||||
| 3 | 51 ± 14 | 0.83 ± 0.15 | 70 ± 2 | 38 ± 11 | 3 |
| 6 | 61 ± 29 | 0.45 ± 0.23 | 71 ± 8 | 38 ± 0 | 2 |
| B. Plasma clots—aged and lysed with alteplase | |||||
| 3 | 98 ± 24 | 0.78 ± 0.11 | 74 ± 6 | 8 ± 2 | 2 |
| 6 | 81 ± 11 | 0.68 ± 0.11 | 70 ± 1 | 9 ± 1 | 2 |
| C. Control aged plasma clots | |||||
| 3 | 29 ± 13 | 0.64 ± 0.09 | 95 ± 4 | — | 4 |
| 6 | 22 ± 9 | 0.70 ± 0.15 | 94 ± 3 | — | 4 |
Thrombin activity present in aged plasma clots, treated with streptokinase or alteplase, was determined with the clot permeation assay, as described in the text and legend to Figs 6 and 7. Average (±SD) of results from plasma samples obtained from a series of individual donors is presented. The maximum activity, IC50, and maximum inhibition parameters were determined by nonlinear regression analysis of each argatroban inhibition data set, as described earlier. The plasmin activity was determined with plasma samples (ie, no thrombin added) to which thrombolytic agent was added, and the results are expressed as a percentage of the thrombin activity present in clotted plasma treated with the same agent.