Background：

Receptor for prostaglandin E2. The activity of this receptor can couple to both the inhibition of adenylate cyclase mediated by G(i) proteins， and to an elevation of intracellular calcium. Required for normal development of fever in response to pyrinogens， including IL1B， prostaglandin E2 and bacterial lipopolysaccharide (LPS). Required for normal potentiation of platelet aggregation by prostaglandin E2， and thus plays a role in the regulation of blood coagulation. Required for increased HCO3- secretion in the duodenum in response to mucosal acidification， and thereby contributes to the protection of the mucosa against acid-induced ulceration. Not required for normal kidney function， normal urine volume and osmolality.