[Study on serotonin metabolism in toxemia of pregnancy].

To evaluate the serotonin (5-HT) metabolism in toxemia of pregnancy, plasma free 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), tryptophan and platelet 5-HT content were determined by high performance liquid chromatography (HPLC) with electrochemical detection. The mean plasma free 5-HT concentrations in the severe preeclamptic group (S) and the mild preeclamptic group (M) were significantly higher than those in the normal group (N). A significant correlation was found between plasma free 5-HT values and Gestosis Index scores. However, there was no significant difference between plasma 5-HIAA level and platelet 5-HT content in the preeclamptic groups and the N. The mean plasma beta-thromboglobulin (beta-TG) concentrations in the preeclamptic groups were significantly higher than those in the N. The mean platelet counts in the S were significantly lower than those in the N. The mean plasma 5-HIAA/5-HT ratio in the preeclamptic groups were significantly lower than those in the N. In conclusion, it is suggested that the higher plasma free 5-HT level in the toxemia of pregnancy seems to be attributed to the excess release of 5-HT from platelets in addition to the lower monoamine oxidase activity.