Prostanoids
Prostanoids are a diverse family of eicosanoids (20-carbon molecules), produced from arachidonic acid, and include:
- Thromboxane
- Prostacyclin
- Prostaglandins
Synthesis
Arachidonic acid is converted into:
- Leukotrienes by LOX
- Cyclic endoperoxidases by COX enzymes
These undergo further metabolism to produce:- Thromboxanes
- Thromboxane A2
- Prostacyclins
- PGI2
- Prostaglandins
- PGE2
- EP1
- EP2
- EP3
- PGF2α
- PGD2
- PGE2
- Thromboxanes
Effects
| Receptor | Receptor | Respiratory | Vascular | GIT | GU | Other |
|---|---|---|---|---|---|---|
| Thromboxane A2 | Gq | Vasoconstriction | Platelet aggregation | |||
| PGI2 | Gs | Bronchodilation | Vasodilation (renal and pulmonary) | |||
| PGE2 EP1 | Gq | Bronchoconstriction | Increased contraction | Renal vasodilation | ||
| PGE2 EP2 | Gs | Bronchodilation | Closure of ductus arteriosus | Decreased contraction | Renal vasodilation | |
| PGE2 EP3 | Gi | Gastric mucous production, GIT contraction | Uterine contraction | |||
| PGF2α | Gq | Bronchoconstriction | Vasoconstriction | Uterine contraction | ||
| PGD2 | Gs | Renal vasodilation | Promotes sleep |
References
- Ricciotti E, FitzGerald GA. Prostaglandins and Inflammation. Arteriosclerosis, thrombosis, and vascular biology. 2011;31(5):986-1000. doi:10.1161/ATVBAHA.110.207449.