[Effects of emetine and ipecacuana on dopamine central mechanisms. A pilot study]

The lack of any rotational behaviour in unilaterally dopamine lesioned animals after ipecacuana or emetine is a strong indication that these substances lack dopamine receptor stimulating properties when administered systematically. Our results thus support those of Lal et al. (1972). Our results do not allow any conclusions concerning the working mechanism of emetine. However, the lack of central dopamine receptor stimulating properties should probably not be explained by an inability to enter through the blood brain barrier but rather a lack of effect on dopamine receptors. This reasoning would also exclude the dopamine receptors in the chemo-trigger zone as responsible for the emetic effect. In terms of the clinical usage of ipecacuana it seems highly improbable that this usage may cause adverse psychotic like side effects due to stimulation of central dopamine receptors.