Table 1. Receptors and transporters for bile acids.
| Membrane receptors | Bile acid affinity | Location |
|---|---|---|
| Takeda G-protein coupled receptor 5 (TGR5) |
LCA, DCA, CDCA, CA, TUDCA |
Liver, intestine, brain, eye (primary retinal ganglion cells) spleen, lung, monocytes |
| Sphingosine 1-phosphate receptor 2 (S1PR2) |
TCA, GCA, TDCA, GDCA, TUDCA |
liver, brain, eye (rat bipolar retinal cells, mouse retinal endothelial cells) heart, lung |
| α5β1 Ιντεγριν |
TUDCA |
Liver, brain, retina (human vessels, astrocytes) |
| Nuclear receptors |
|
|
| Farsenoid X receptor (FXR) |
LCA, DCA, CDCA, CA |
Liver, intestine, brain |
| Vitamin D receptor (VDR) |
LCA |
Intestine, liver, bone, kidneys, retina and cells (βcells, adipocytes, vascular smooth muscle cells, monocytes) |
| Pregnane X receptor (PXR) |
LCA |
Liver, intestine, brain, retina (RPE cells) |
| Glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) |
UDCA,TCA,GDCA, TUDCA |
Liver, brain, retina |
| Constitutive androstane receptor (CAR) |
CA |
Liver, brain, kidney, adrenals |
| Transporters |
|
|
| Apical sodium-dependent bile acid transporter (ASBT) |
Unconjugated and conjugated bile acids |
Intestine, cholangiocytes, brain |
| Sodium taurocholate cotransporting polypeptide (NTCP) |
Unconjugated and conjugated bile acids |
Liver, brain |
| Organic anion-transporting polypeptide (OATP) |
Unconjugated and conjugated bile acids |
Liver, Intestine, brain, retina |
| Multidrug resistant protein (MRP), 2, 3, 4 |
TCA, CA and conjugated bile acids |
Liver, Brain, retina |
| Bile salt export pump (BSEP) | Conjugated bile acids | Liver, brain |
LCA: lithocholic acid, DCA: deoxycholic acid, CDCA: chenodeoxcholic acid, CA: cholic acid, UDCA: ursodeoxycholic acid, TCA: taurocholic acid, GDCA: glycodeoxycholic acid, TUDCA: tauroursodeoxycholic acid, RPE: retinal pigment epithelium