Table 2.
Influence of sildenafil on the anticonvulsant activity of selected AEDs in the s.c. PTZ seizure test in mice
| Treatment (mg/kg) | ED50 (mg/kg) | n | SEM |
|---|---|---|---|
| CZP + saline | 0.022 (0.015–0.032) | 24 | 0.0042 |
| CZP + sildenafil (10) | 0.015 (0.011–0.020) | 32 | 0.0023 |
| CZP + sildenafil (20) | 0.020 (0.016–0.024) | 28 | 0.0020 |
| CZP + sildenafil (40) | 0.013 (0.010–0.019) | 23 | 0.0021 |
| VPA + saline | 121.4 (104.9–140.5) | 32 | 9.04 |
| VPA + sildenafil (10) | 127.4 (107.2–151.4) | 24 | 11.21 |
| VPA + sildenafil (20) | 121.0 (102.3–143.3) | 47 | 10.41 |
| VPA + sildenafil (40) | 101.0 (82.4–123.8) | 24 | 10.50 |
| PB + saline | 12.68 (10.62–15.13) | 28 | 1.15 |
| PB + sildenafil (10) | 11.83 (9.04–15.47) | 27 | 1.62 |
| PB + sildenafil (20) | 13.94 (12.30–15.80) | 32 | 0.89 |
| PB + sildenafil (40) | 13.03 (11.08–15.33) | 24 | 1.08 |
| TGB + saline | 0.88 (0.61–1.25) | 32 | 0.16 |
| TGB + sildenafil (10) | 0.86 (0.62–1.20) | 16 | 0.14 |
| TGB + sildenafil (20) | 0.74 (0.58–0.97) | 32 | 0.10 |
| TGB + sildenafil (40) | 0.75 (0.59–0.94) | 24 | 0.09 |
| ETS + saline | 155.8 (139.7–173.7) | 31 | 8.66 |
| ETS + sildenafil (10) | 140.4 (127.6–154.4) | 24 | 6.83 |
| ETS + sildenafil (20) | 120.3 (101.0–143.2)a | 24 | 10.73 |
| ETS + sildenafil (40) | 72.29 (58.59–89.20)b | 24 | 7.76 |
Data are presented as median effective doses of AEDs (ED50: the dose which protects 50% of animal tested from PTZ-induced clonic seizures) with 95% confidence limits in parentheses. PTZ was administered s.c. at a dose of 96.1 mg/kg, which was its CD97 (a dose of PTZ provoking clonic convulsions in 97% of animal tested). ED50 values were calculated according to the log-probit method described by Litchfield and Wilcoxon (1949). One-way ANOVA was used to compare ED50 values; CZP F(3, 103) = 2.017; p = 0.116; VPA F(3, 123) = 0.904; p = 0.441; PB F(3, 107) = 0.722; p = 0.541; TGB F(3, 100) = 0.309; p = 0.819; ETS F(3, 99) = 17.540; p < 0.001. n total number of animals at those doses of AEDs whose anticonvulsant effect was between 4 and 6 probits; SEM, standard error of the mean of ED50 values; a p < 0.05; b p < 0.001 versus AED + saline-treated group