Table 1.
Inhibitor assays of PDE8
| Inhibitor | Selective for PDE Type (IC50) | IC50 for PDE8, μM |
|---|---|---|
| IBMX | non-selective (2–50 μM) | >200 |
| Zaprinast | PDE5/6 (0.76/0.15 μM) | >100 |
| EHNA | PDEZ (1 μM) | >100 |
| Enoximone | PDE3 (1 μM) | >100 |
| Dipyridamole | PDE5/6 (0.9/0.38 μM) | 4.5 |
| Sildenafil | PDE5 (3.9 μM) | >30 |
| SCH 51806 | PDE1/5 (0.1 μM) | >100 |
| Ro 20-1724 | PDE4 (2.0 μM) | >200 |
| Rolipram | PDE4 (2.0 μM) | >200 |
| Papaverine | nonselective (0.4–20 μM) | 174 |
Only dipyridamole and papaverine have any effect on PDE8 within the dose ranges. Rolipram, Ro 20-1724 and IBMX do not inhibit PDE8 within dose ranges considered specific.