TABLE 2.
Antagonist Activity at Group 1 P2X Receptors
| Compound | rP2X1
|
rP2X3
|
||||
|---|---|---|---|---|---|---|
| IC50 (nM) | CI (nM) | nH | IC50 (nM) | CI (nM) | nH | |
| PPADS | 68.5 | 45.9 – 102.2 | −1.87 | 213.6 | 173.0 – 263.7 | −1.17 |
| isoPPADS | 34.5 | 25.3 – 47.1 | −1.48 | 78.8 | 57.4 – 108.0 | −1.46 |
| MRS 2143 | 32.4 | 26.5 – 40.4 | −0.97 | 345.3 | 240.6 – 495.4 | −0.88 |
| MRS 2159 | 9.4 | 6.6 – 13.4 | 1.08 | 117.7 | 93.4 – 148.3 | −1.02 |
| MRS 2191 | 8.9 | 5.9 – 13.6 | −0.84 | 228.6 | 171.0 – 305.5 | −1.01 |
| MRS 2257 | 5.1 | 3.6 – 7.3 | −1.02 | 21.8 | 13.8 – 34.5 | −1.13 |
| MRS 2273 | 11.3 | 7.5 – 17.1 | −0.86 | 32.9 | 25.8 – 41.9 | −1.15 |
| MRS 2284 | 7.1 | 6.0 – 8.4 | −1.98 | 139.0 | 114.1 – 169.3 | −1.33 |
| MRS 2285 | 21.9 | 17.4 – 27.5 | −1.9 | 259.8 | 222.3 – 303.8 | −1.34 |
| Ip5I | 3.13 | 2.09 – 4.69 | −0.94 | 2059.0 | 1252.0 – 3388.0 | −1.43 |
| TNP-ATP | 1.01 | 0.69 – 1.47 | −0.78 | 0.34 | 0.25 – 0.46 | −0.82 |
Each compound was tested against ATP-responses (rP2X1, 1 μM; rP2X3, 3 μM). Antagonist activity is expressed as mean IC50 value (nM, for four determinations) with confidence intervals for the mean at the 95% level (CI, nM). The mean Hill coefficient (nH) is also given for each set of inhibition curves.