Effect of a new eburnamine derivative, RU 24722, on the turnover of monoamines in mouse brain: selective and...

A new eburnamine derivative, RU 24722, is structurally similar to vincamine and is known to cause a specific and reversible decrease of noradrenaline in rat brain. The effects of RU 24722 on the turnover of monoamines in mouse brain were investigated. The noradrenaline level in mouse brain was significantly decreased after administration of RU 24722 10 mg/kg i.p. with significant increases in 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid and homovanillic acid. The levels of these compounds returned to the control levels within 5 h. The levels of dopamine, serotonin, 5-hydroxyindoleacetic acid and histamine were not affected by this dose of RU 24722. Higher doses of RU 24722 (25 and 50 mg/kg) decreased the concentration of serotonin significantly with a significant increase in 5-hydroxyindoleacetic acid. There were no differences between the patterns of change in the forebrain, midbrain and hindbrain. These results indicate that RU 24722 increased the turnover of noradrenaline and dopamine in mouse brain at the dose of 10 mg/kg and the turnover of serotonin was also increased only at higher doses.