Figure 13.

Effect of Ro31-8220 on [³H]dopamine release from rat striatum. For the experimental procedure, see Figure 2A. (A) Filled circles indicate [³H]dopamine release in the presence and absence of Ro31-8220. Ro31-8220 was added to striatal slices from fraction 8 in a concentration of 1 µmol/L and maintained throughout the experiment. Resting release expressed by the B2/B1 ratio was 0.81 ± 0.03 in control and it was 0.90 ± 0.09 in the presence of Ro31-8220, the difference was not significant. The electrical stimulation-induced release expressed by the S2/S1 ratio was 0.80 ± 0.07 in control and it was 0.47 ± 0.10 in the presence of Ro31-8220, p < 0.05. Student t-statistics for two-means, mean ± S.E.M., n = 3-4. (B) Ro31-8220 concentration-dependently decreased electrical stimulation-induced [³H]dopamine release from rat striatum. Ro31-8220 was added to striatal slices from fraction 8 in concentrations varied from 0.1 to 10 µmol/L and maintained through the experiment. 10 µmol/L Ro31-8220 reduced electrical stimulation-induced [³H]dopamine release, * p < 0.01. One-way ANOVA followed by the Dunnett’s test, F(3,13) = 4.489, p = 0.022, mean ± S.E.M., n = 3-6.