Table 2.
Potency (pEC50) and efficacy (Emax) of FK506 and cyclosporine as inhibitors of ionophore A23187-induced histamine release from mast cells and basophils
|
FK506 |
Cyclosporine |
|||
|---|---|---|---|---|
| Emax (%) | pEC50 | Emax (%) | pEC50 | |
| Basophils | 97±3 | 8.3±0.1 | 98±2 | 7.5±0.3 |
| Mast cells | 56±5 | 8.7±0.3 | 69±6 | 7.3±0.3 |
Values shown are for the inhibition of ionophore A23187-mediated histamine release from mast cells and basophils by FK506 (10−10 to 10−6 M) and cyclosporine (10−9 to 10−5 M). Mast cells and basophils were incubated for 5 min with or without an inhibitor before challenge with ionophore A23187 (0.2 μM). Control histamine releases ranged from 27±5 to 40±5%. Data are means±s.e.m. and are based on four (basophils) to 10 (mast cells) experiments for FK506 and on eight (basophils) to 14 (mast cells) experiments for cyclosporine.