What is the difference between PGD2 and PGE2?

These two belong to different types of prostaglandins. Prostaglandin E2 (PGE2) is the most abundant prostaglandin and is produced by the action of prostaglandin E synthetase on prostaglandin H2(PGH2). Prostaglandin D2(PGD2) is another prostaglandin produced by hematopoietic and lipoprotein prostaglandin D synthase (hPGDS and lPGDS) acting on prostaglandin H2(PGH2). In addition, the two have different receptors and different areas of study. PGE2: Mainly studies gastrointestinal smooth muscle PGD2: Studies allergic diseases such as asthma