Antagonist pharmacology of hGluR3i determined by [Ca++]i measurements in HEK69-8 cells
| Compound | IC50values | nH | Kbvalues | Statistics | n |
|---|---|---|---|---|---|
| μM | μM | ||||
| NBQX | 0.38 (0.28, 0.52) | −1.1 ± 0.2 | 0.31 (0.22, 0.42) | c,d,y,s,g | 4 |
| DNQX | 2.09 (1.73, 2.52) | −1.3 ± 0.1 | 1.66 (1.38, 2.00) | n,s,g | 4 |
| YM-90K | 2.45 (2.04, 2.93) | −1.5 ± 0.2 | 1.96 (1.64, 2.35) | n,s,g | 3 |
| CNQX | 2.64 (2.13, 3.28) | −1.1 ± 0.2 | 2.11 (1.68, 2.67) | n,s,g | 8 |
| NS257 | 10.5 (7.33, 15.2) | −1.5 ± 0.3 | 8.45 (5.87, 12.2) | n,c,d,y,g | 4 |
| GYKI-52466 | 34.0 (22.5, 51.5) | −1.3 ± 0.1 | † | – | 3 |
| GAMS | 1140 (977, 1331) | −1.5 ± 0.2 | 913 (782, 1070) | n,c,d,y,s | 4 |
| AMOA | ≫300 | – | – | – | 4 |
| NS102 | ≫300 | – | – | – | 4 |
Kb or IC50 values determined for antagonists against hGluR3i, expressed as the geometric mean (lower, upper S.E.), and the Hill slope, nH, expressed as the mean ± S.E. Antagonist studies were performed with 30 μM glutamate. The dissociation constants (Kb values) were derived from IC50 values with the Leff-Dougall variant of the Cheng-Prusoff equation (Leff and Dougall, 1993). † Kb values were not calculated because GYKI-52466 is a noncompetitive antagonist. Statistics were performed onKb values with ANOVA followed by Student-Newman-Keuls pairwise comparison. Differences (P < .05) are indicated by the letters: n, c, d, y, s and gwhere values are different from NBQX, CNQX, DNQX, YM-90K, NS257 and GAMS, respectively.