Description
The biological effects of prostaglandin D
2 (PGD
2) are transduced by at least two 7-
transmembrane G protein-
coupled receptors, designated DP
1 and CRTH2/DP
2. In humans, CRTH2/DP
2 is expressed on Th2 cells, eosinophils, and basophils where it mediates the chemotactic activity of PGD
2. CAY10597, as a racemic mixture, is a potent CRTH2/DP
2 receptor antagonist that binds to the human receptor with a K
i value of 37 nM. The R enantiomer is slightly more potent exhibiting K
i values of 23 and 22 nM at the human and murine CRTH2/DP
2 receptor, respectively. The R enantiomer of CAY10597 inhibits eosinophil chemotaxis induced by 13,14-
dihydro-
15-
keto-
prostaglandin D
2 with an IC
50 value of 40 nM.
