Figure 8.

The α₁-adrenergic receptor antagonist prazosin does not affect the antihyperalgesic and antiallodynic effects of gabapentin. Prazosin HCl (pra) was administered either i.p. ((a); 1 mg kg⁻¹) or i.t. ((b); 3 μg) 15 min before the administration of gabapentin (gbp, 100 mg kg⁻¹, i.p., administered at time zero). Each point represents the mean±s.e.m. of six or seven separate experiments (open circle; gabapentin-only, closed triangle; prazosin-treated). Ordinates: mean PWLs (plantar test; left) and 50% thresholds (von Frey test; right). Abscissae: 7 days before (pre-ope) and time in minutes after gabapentin application. Open diamond in each graph shows the mean of pooled PWLs (left in (a) and (b)) or 50% thresholds (right in (a) and (b)) obtained before ligation in the two groups of mice.