Biogenic amine levels in the mid-term human fetus.

Spectrophotofluorometric assays were used to measure concentrations of DA, NA, 5-HT and 5-HIAA present in extracts of brain tissue and CSF taken from midterm gestational fetuses of both sexes. The presence of biogenic amines was demonstrated in fetuses as early as 10.5 weeks gestation. In the hypothalamus, the concentrations (expressed in ng/100 mg tissue) ranged from 10.2 to 62.2 for NA, 11.6 to 258.8 for DA, 7.6 to 38.6 for 5-HT and 56.6 to 114.1 for 5-HIAA. Concentrations of DA and 5-HT were found to be significantly (P less than 0.05) higher in the hypothalamus than in the cortex, but those of NA and 5-HIAA were similar in both areas. No sex difference was observed. The concentrations of biogenic amines in the CSF (expressed in ng/ml) were 63.1-286.7 for NA, 43.2-108.1 for DA, 30.9-87.5 for 5-HT and 8.0-42.8 for 5-HIAA.