[Effect of beta-phenylethylamine derivatives on the central nervous system. III. Motor activity changes in mice due to the intracerebral administration of metaraminol].

Influence of metaraminol on behavioural changes in mice was studied with the following results. 1) When metaraminol was injected i.c., spontaneous motor activity as tested by either the photocell counters method or open-field test markedly increased within 90 min after injection, while on the contrary greatly decreased 3 hr later as compared with control group. Thus, these biphasic effects of metaraminol were clearly established. 2) 30 min after injection, metaraminol in doses of 160 mug did not alter brain catecholamines in mice, however, 6 hr after injection, brain dopamine and norepinephrine markedly decreased. 3) When metaraminol was injected into mice pretreated with reserpine of 6-hydroxydopamine, spontaneous motor activity tested by photo-cell counters method markedly increased and anti-6-hydroxydopamine activity of metaraminol was stronger than anti-reserpine. 4) Metaraminol completely antagonized ptosis and catalepsy induced by rerserpine. 5) Six hr after injection, anti-methamphetamine activity was observed.