Table 1.
Affinity of a panel of B2 receptor antagonists in inhibiting tritiated BK bound to lung and ileum tissue membranes
|
[3H]-BK binding |
||||
|---|---|---|---|---|
|
Lung |
Ileum |
|||
| Antagonist | pIC50 (95% c.l.) | % of not inhibited specific binding | pIC50 (95% c.l.) | % of not inhibited specific binding |
| Icatibant | 10.7 (10.4–10.9) | 55±2 | 10.2 (10.1–10.4) | 7±4 |
| MEN11270 | 10.4 (10.2–10.7) | 57±4 | 9.9 (9.8–10.1) | 11±4 |
| MEN16132 | 10.5 (10.3–10.8) | 53±3 | 9.9 (9.7–10.1) | 12±4 |
| LF16-0687 | 8.9 (8.7–9.1) | 50±5 | 8.8 (8.6–9.0) | 11±6 |
| FR173657 | 8.6 (8.4–8.8) | 52±2 | 8.2 (8.0–8.4) | 10±5 |
Abbreviations: BK, bradykinin; c.l., confidence limit.
Antagonists inhibition curves were performed with [3H]-BK (0.15 nM) binding in mouse lung and ileum membranes. Values of pIC50 and the percentage of radioligand specific binding which was not inhibited by ligands at 1 μM concentration are indicated. Data are from four independent experiments each one performed in duplicate. Inhibition curves obtained with Icatibant and MEN16132 are shown in Figure 3.