[Inhibitory effects of methyl o-(4-hydroxy-3-methoxycinnamoyl) reserpate (CD-3400) on the central nervous system (author's transl)].

Effects of methyl o-(4-hydroxy-3-methoxycinnamoyl) reserpate (CD-3400) on the central nervous system in mice, rats and cats were investigated, and a comparison was made with such effects of reserpine and rescinamine. Inhibitory effects of CD-3400 on spontaneous motor activity and conditioned avoidance response were weaker and shorter than those of reserpine and rescinnamine. In the experiments of the inhibitory effects of the central actions such as ptosis, hypothermia, decrease in motor ability, potentiation of hexobarbital and taming, reserpine was found to be the most potent followed by rescinnamine and CD-3400, respectively. High doses of CD-3400 exhibited inhibitory effects on methamphetamine-induced hyperactivity in mice and this action was weaker than those of reserpine and rescinnamine. CD-3400, 80-160 mg/kg p.o., showed no significant effects on morphine-induced analgesia, while a slight inhibition was observed on the Straub-tail reaction using morphine. Reserpine, 0.5 mg/kg i.v., resulted in a drowsy pattern in the spontaneous EEG activity and the EEG arousal response was depressed, while with CD-3400, 5 mg/kg i.v., there was no drowsy pattern. CD-3400 as well as rescinnamine and reserpine remarkably depleted 5-HT levels in brain, heart and plasma and the potency of CD-3400, particularly in the brain, was weaker than the potency of reserpine and rescinnamine. These results indicate that CD-3400 is an antihypertensive agent with a low toxicity and a weak central action.