Involvement of α₁ but Not α₂-Adrenergic Systems in the Antagonizing Effect of Paeoniflorin on Scopolamine-Induced Deficit in Radial Maze Performance in Rats

Abstract

Paeoniflorin, a major constituent of peony root (1 mg/kg, p.o.), attenuated scopolamine-induced deficit in radial maze performance. Both prazosin (0.5 mg/kg, i.p.) and yohimbine (0.3 mg/kg, i.p.) neither impaired radial maze performance by itself nor augmented the scopolamine-induced performance deficit. Prazosin significantly blocked the antagonizing effect of paeoniflorin on the scopolamine deficit, whereas yohimbine did not affect the paeoniflorin effect. These data suggest that the α₁-adrenergic but not α₂-adrenergic systems are involved in the antagonizing effect of paeoniflorin on the scopolamine deficit in radial maze performance in rats.