PGD2 is a prostaglandin which binds to the receptor PTGDR, as well as CRTH2. It is a major prostaglandin produced by mast cells – recruits Th2 cells, eosinophils, basophils. In mammalian organs, large amounts of PGD2 are found in the brain, in mast cells and found nowhere else. It is critical to development of allergic diseases such as asthma.
Causes a contraction of the bronchial airways. The concentration of PGD2 in asthma-patients is 10 times higher than in control patients, especially after it is brought into contact with allergens. Involved in the regulation of reducing body temperature, in sleep, and acts opposite to prostaglandin E2.