RO1138452 (CAY10441) is a selective and orally bioavailable antagonist of prostacyclin receptor (pKi: 8.3). It antagonizes the carbaprostacyclin-induced activation of human neuroblastoma adenylate cyclase, blocking cyclic AMP accumulation in a dose-dependent manner. Likewise, it inhibits the binding of tritiated iloprost to rodent neuroblastoma cells with a Ki of about 1.5 nM. At levels between 2-20 mg/kg in rats, CAY10441 shows significant analgesic activity in standard antinociceptive assays [1].

Selective prostacyclin IP receptor antagonist (pKi = 8.3). Exhibits no affinity at other prostanoid receptors (EP1-4, FP and TP) in a radioligand binding assay. Demonstrates analgesic activity in rats. Orally bioavailable. Clark et al (2004) Discovery and SAR development of 2-(phenylamino) imidazolines as prostacyclin receptor antagonists. Bioorg.Med.Chem.Lett. 14 1053 PMID:15013022 |Jones et al (2006) Investigation of the prostacyclin (IP) receptor antagonist RO1138452 on isolated blood vessel and platelet preparations. Br.J.Pharmacol. 149 110 PMID:16880763 |Bley et al (2006) RO1138452 and RO3244794: characterization of structurally distinct, potent and selective IP (prostacyclin) receptor antagonists. Br.J.Pharmacol. 147 335 PMID:16331286