Table 4.
Changes in the expression of serotonin components in human placenta in the third trimester compared with the first trimester of pregnancy.
| Gene | Location | mRNA/protein | First trimester | Term | Change* | Study |
|---|---|---|---|---|---|---|
| Enzymes | ||||||
| TPH1 | Tissue homogenate | mRNA | y | y | ↓ | (69) |
| Tissue homogenate | protein | y | y | = | (69) | |
| Tissue homogenate | activity | y | y | = | (69) | |
| TPH2 | Tissue homogenate | mRNA | y | y | = | (69) |
| Tissue homogenate | mRNA | n | y | ↑ | (68) | |
| MAOA | Tissue homogenate | mRNA | y | y | ↓ | (69) |
| Tissue homogenate | protein | y | y | = | (69) | |
| Tissue homogenate | activity | y | y | ↑ | (69) | |
| Syncytiotrophoblast | protein | y | y | = | (82) | |
| MAOB | Cytotrophoblasts | mRNA | n | y | ↑ | (87, 88) |
| Transporters | ||||||
| SERT | Tissue homogenate | mRNA | y | y | ↓ | (69) |
| (SLC6A4) | protein | y | y | ↑ | (69) | |
| OCT1 | Tissue homogenate | mRNA | y | y | = | (74) |
| (SLC22A1) | ||||||
| OCT2 | Tissue homogenate | mRNA | y | y | ↓ | (74) |
| (SLC22A2) | ||||||
| OCT3 | Tissue homogenate | mRNA | y | y | = | (69, 75) |
| (SLC22A3) | Tissue homogenate | protein | y | y | ↑ | (69, 75) |
| Tissue homogenate | mRNA | y | y | ↓ | (74) | |
| Cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) | |
| Extravillous cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) | |
| PMAT | Cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) |
| (SLC29A4) | ||||||
| Receptors | ||||||
| HTR1D | Cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) |
| Syncytiotrophoblast | mRNA | n | y | ↑ | (87, 88) | |
| Extravillous cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) | |
| HTR2A | Cytotrophoblasts | mRNA | n | y | ↑ | (87, 88) |
| HTR2B | Syncytiotrophoblast | mRNA | n | y | ↑ | (87, 88) |
| HTR7 | Cytotrophoblasts | mRNA | y | n | ↓ | (87, 88) |
y: detected, n: not detected.
* ↑, up-regulated; ↓, down-regulated; =, no change at term of pregnancy compared to first trimester.