Figure 11.

(A) EPPTB decreased the (±)methamphetamine (methamph)-induced non-vesicular [³H]dopamine release in rat striatum. For the experimental procedure, see Figure 2B. (±)Methamphetamine (10 µmol/L) was added to striatal slices from fraction 12 and maintained through the experiment in the presence and absence of EPPTB. EPPTB (1 µmol/L) was added to striatal slices from fraction 3 and maintained throughout the experiment. (±)Methamphetamine-induced [³H]dopamine release was 12.42 ± 1.46 and this release was decreased to 4.20 ± 1.62 percent of content by 1 µmol/L EPPTB, p < 0.01; Student t-statistics for two-means, mean S.E.M., n = 4-8. (B) EPPTB (0.1 and 1 µmol/L) antagonized the effect of (±)methamphetamine on resting but not on electrical stimulation-induced [³H]dopamine release in rat striatum. For the experimental procedure, see Figure 2A,B. (±)Methamphetamine was added to striatal slices from fraction 8 in a concentration of 6.75 µmol/L. When used, EPPTB was added to the slices in a concentration of 0.1 or 1 µmol/L from fraction 1 and drugs were maintained throughout the experiment. Resting [³H]dopamine release (defined as the fractional release between fractions 8 and 17) was 0.37 ± 0.08 in control and 4.27 ± 0.46 percent of content in the presence of (±)methamphetamine, this release was decreased by EPPTB. The electrical-induced [³H]dopamine release (S2/S1) was 0.89 ± 0.03 in control and 1.86 ± 0.32 in the presence of (±)methamphetamine; this release was not altered by EPPTB. One-way ANOVA followed by the Dunnett’s test, F(3,26) = 13.990, p < 0.001 for resting [³H]dopamine release and F(3,26) = 5.554, p < 0.004 for electrical stimulation-induced [³H]dopamine release, # p < 0.05 control vs. (±)methamphetamine effect, * p < 0.05 (±)methamphetamine vs. (±)methamphetamine and EPPTB effect, mean ± S.E.M., n = 6-8.