[Central effects of beta-phenylethylamines. (8). Increase in spontaneous motor activities of mice caused by intracerebrally administered metaramino].

Metaraminol (MA) (40, 80 and 160 microng) was injected i.c. into mice and spontaneous motor activity (SMA) measured by photo-cell counters method was found to increase 30 min after the injection. Ninety min after, the SMA was restored to the saline treated control. MA (80 microng i.c.) was also injected into isocarboxazide (Iso) pretreated mice and the SMA markdly increased as compared with the Iso+saline treated group or tween+MA treated group. When MA was injected i.c. into alpha-methyl-p-tyrosine (alpha-MT) pretreated mice, the SMA significantly increased as compared with that of the alpha-MT+saline treated group, but there was a decrease as compared with that of the tween+saline or tween+MA treated group. In alpha-MT treated mice. L-Dopa restored the hyper-motor activity of animals treated with MA. Diethyldithiocarbamate (700mg/kg i.p.) had no influence, whereas haloperidol markedly blocked the hyper-motor activity induced by MA. The hyper-motor activity induced by MA in mice raised the question of a possible role of noradrenaline and dopamine in the mediation of this action.