Table 1.
Effects of PA-6 and its synthetic analogues on responses of GluN1/GluN2B receptors in HEK293 cells to glutamate
| NS | Steroid concentration (µmol·L−1) | Mean % change ±SD (n) | IC50 (µmol·L−1) |
|---|---|---|---|
| PA-4 | 200 | +1.9 ± 6.2 (4) | ND |
| PA-5 | 200 | +14.1 ± 7.5 (5) | ND |
| PA-6 | 100 | −84.4 ± 3.4 (5) | 24.6 ± 5.3 |
| 3–300 | (5) | 31.1 ± 5.9 (DR) | |
| PA-11 | 200 | −71.5 ± 13.3 (4) | 97.3 ± 48.3 |
| PA-12 | 200 | −84.7 ± 0.6 (4) | 48.1 ± 1.8 |
| PA-13 | 100 | −69.2 ± 7.0 (6) | 51.9 ± 14.2 |
| PA-14 | 100 | −80.9 ± 3.6 (4) | 30.1 ± 5.9 |
| PA-15 | 50 | −81.6 ± 6.1 (6) | 14.4 ± 4.9 |
| PA-18 | 200 | −83.6 ± 2.7 (5) | 51.7 ± 8.6 |
| PA-21 | 50 | −63.7 ± 2.9 (5) | 31.4 ± 3.3 |
| PA-22 | 200 | −87.3 ± 8.9 (4) | 40.8 ± 27.8 |
| PA-25 | 200 | −77.1 ± 5.2 (5) | 73.4 ± 18.0 |
| PA-27 | 10 | −69.2 ± 9.6 (7) | 5.3 ± 2.1 |
| 0.3–30 | (7) | 6.8 ± 1.3 (DR) | |
| PA-33 | 50 | −31.5 ± 2.5 (4) | 95.9 ± 8.8 |
| PA-34 | 200 | −61.5 ± 10.6 (5) | 141.1 ± 54.3 |
| PA-35 | 10 | −65.4 ± 3.4 (5) | 5.9 ± 0.7 |
| PA-36 | 200 | −54.0 ± 10.8 (5) | 184.0 ± 70.2 (S) |
| PA-17 | 100 | −54.1 ± 8.4 (5) | 89.7 ± 23.8 |
The structures of PA-6 and its C3-substituted analogues are shown in Figure 1. The effect of the steroids on the current induced by fast application of 100µmol·L−1 glutamate is expressed as % change (means ± SD), with n indicating the number of cells studied. The IC50 values (means ± SD) were calculated from the single concentrations shown and, for PA-6 and PA-27, also from a full concentration-response curve (marked DR), as described in the text.