Effect of Toki-shakuyaku-san on acetylcholine level and blood flow in dorsal hippocampus of intact and twice-repeated ischemic rats.

The effects of Toki-shakuyaku-san (TSS) ingredients on acetylcholine (ACh) release in the dorsal hippocampus (DH) were investigated in intact and twice-repeated ischemic rats using in vivo microdialysis-HPLC. Moreover, the effect of TSS on blood flow was investigated in intact rats using laser Doppler flowmetry. TSS at 300 mg/kg p.o. increased ACh and blood flow after 40 min in intact rats. TSS also increased ACh in ischemic rats but to a lesser extent than in intact rats. These results could suggest that TSS-increased ACh and blood flow in DH may contribute in the cognition improving property of TSS.