Prostaglandin E receptors
The four prostaglandin E receptors (abbreviated EP1 to EP4 ) are G-protein-coupled receptors that mediate the complex effects of prostaglandin E 2 (abbreviated: PGE 2 ) in different ways. They belong to the superordinate group of prostaglandin receptors .
Lower forms
EP1
- conveys the pain-intensifying effect of the PGE 2 .
- mediates a contracting effect on gastric smooth muscle cells through PGE 2 .
EP2
- Conveys the muscle-relaxing effect of PGE 2 on the smooth vascular muscles of arteries and thus leads to the typical reddening of local inflammations .
EP3
- conveys the fever-inducing effect of PGE 2 .
- mediates the acid-inhibiting effect of PGE 2 on the parietal cells of the stomach and promotes the formation of a neutralizing mucus that protects the gastric mucosa. This is the main reason why NSAIDs , which inhibit cyclooxygenase and thus suppress the formation of prostaglandins, lead to increased acid production and serious complications such as gastric bleeding, ulcers and the like can occur with long-term treatment.
EP4
The EP4 receptor normally keeps the ductus arteriosus open before birth. Mice that are unable to develop an EP4 receptor due to a genetic defect die after 72 hours with an open ductus arteriosus. It is speculated that without EP4 receptors, other (as yet unknown) factors will keep the ductus arteriosus open, but that they will not cease to work with birth. Likewise, mice that are unable to develop COX-1 and COX-2 cannot close the duct after birth. The exact process of circulatory adaptation after birth has not yet been clarified.
Individual evidence
- ↑ a b Simmons, D. et al. (2004): Cyclooxygenase Isoenzymes: The Biology of Prostaglandin Synthesis and Inhibition. Pharmacol Rev 56: 387-437.