抄録
The relevance of endogenously released DOPA to the (±)-nicotine-induced increase in locomotor activities was explored in rats. This increase was dose (0.1-1.0 mg/kg, s.c.)-dependent, stereo-selective and mecamylamine (1.0 mg/kg, s.c.)-sensitive, but was not antagonized by L-dopa methyl ester (200 pg, i.v.t.), a competitive L-dopa antagonist. Then, by microdialysis, low doses of α-methyl-p-tyrosine (α-MPT, i.p.) at 1-10 mg/kg, were tested to find a dose that selectively inhibits the basal DOPA release in the striata: the release was consistently inhibited by 3 mg/kg without any tendency to inhibit the basal dopamine release. Pretreatment with this dose did inhibit the nicotine-induced increases in locomotor activities. This suggests that endogenously released DOPA is in part relevant to the nicotine-induced behavior in rats.
