Fig. 2

Placental uptake and metabolism of fetal 5-HT in the dually perfused human placenta. 100 nM (A) or 100 µM (B) 5-HT was added to the fetal inflow compartment and samples were collected from the fetal outflow and maternal reservoir for analysis of 5-HT and 5-HIAA levels. At a fetal inflow 5-HT concentration of 100 nM, no 5-HIAA was detected in the maternal reservoir or fetal outflow (A). However, after 20 min of perfusion with 100 µM 5-HT, 5-HIAA was detected in the maternal reservoir (B). Additionally, the placental capacity to remove 5-HT from the fetal circulation was concentration-dependent (C). Data are presented for individual biological replicates with lines connecting median values or as medians with interquartile ranges; n = 5. Statistical significance was evaluated using the Mann-Whitney test. * p ≤ 0.05