Prostaglandin D(2) (PGD(2)) is one of the prostanoids produced during inflammation. Although PGD(2) is known to decrease endothelial permeability through D prostanoid (DP) receptor stimulation, the detailed mechanism is unknown.
Kobayashi, K., Tsubosaka, Y., Hori, M., Narumiya, S., Ozaki, H., & Murata, T. (2013). Prostaglandin D2-DP signaling promotes endothelial barrier function via the cAMP/PKA/Tiam1/Rac1 pathway. Arteriosclerosis, Thrombosis, and Vascular Biology, 33(3), 565–571. https://doi.org/10.1161/ATVBAHA.112.300993