BW A868C is a novel, selective and potent competitive antagonist of prostaglandin D2 (PGD2) [1].

Prostaglandin D2 has been widely distributed in rat brain, spinal cord and pituitary and may act as a neuromodulator in the central nervous system [2]. Prostaglandin D2 is critical for the development of allergic diseases such as asthma.

In vitro: In glycerol-lysed human platelets, BW245C activated adenylate cyclase in a biphasic manner. BW A868C showed no effect on carbacyclin, iloprost, prostacyclin, PGE1 and PGE2 at a concentration 1,000 fold that of its KB against PGD2 and BW245C [1]. BW A868C showed no effect on human TP, IP, EP1, EP2, and FP receptors. The Ki value for BW A868C is approximately 1.7 nM[1] .In isolated rings of rabbit saphenous vein (RbSV) pre-contracted with 40 mM KCl, BW245C caused concentration-dependent relaxations with an EC50 of 38 nM [3].

References:
[1] Giles H, Leff P, Bolofo M L, et al.  The classification of prostaglandin DP‐receptors in platelets and vasculature using BW A868C, a novel, selective and potent competitive antagonist[J]. British journal of pharmacology, 1989, 96(2): 291-300.
[2] Shimizu T, Mizuno N, Amano T, et al.  Prostaglandin D2, a neuromodulator[J]. Proceedings of the National Academy of Sciences, 1979, 76(12): 6231-6234.
[3] Lydford S J, McKechnie K C W, Leff P.  Interaction of BW A868C, a prostanoid DP-receptor antagonist, with two receptor subtypes in the rabbit isolated saphenous vein[J]. Prostaglandins, 1996, 52(2): 125-139.