Figure 1.

Effects of dopamine D₁ and D₂ receptor agonists and antagonists on plasma glucose levels in mice. (a) Effect of SKF 38393 (3 and 10 μg, i.c.v.) on plasma glucose levels. (b) Effect of SCH 23390 (1 and 3 μg, i.c.v.) on plasma glucose levels. (c) Effect of quinpirole (3 and 10 μg, i.c.v) on plasma glucose levels. (d) Effect of l-sulpiride (3 and 10 μg, i.c.v.) on plasma glucose levels. (e) Effect of l-sulpiride on hyperglycemia induced by quinpirole. l-Sulpiride (2 μg, i.c.v.) was co-administered with quinpirole (10 μg, i.c.v.). Each point represents the mean ± S.E.M. of 7–16 mice. **P < 0.01, ***P < 0.001 vs. vehicle group.^#P < 0.05, ^##P < 0.01 vs. quinpirole group.