RO1138452

RO1138452 is IP receptor antagonist. The pIC ₅₀ values of RO1138452 in attenuating cAMP accumulation is 7.0±0.07. Functional antagonism of RO1138452 is studied by measuring inhibition of carbaprostacyclin-induced cAMP accumulation in CHO-K1 cells stably expressing the human IP receptor. The antagonist affinity (pK _i ) of RO1138452 is 9.0±0.06. Selectivity profiles for RO1138452 are determined via a panel of receptor binding and enzyme assays. RO1138452 displays affinity at imidazoline ₂ (I ₂ ) (8.3) and platelet activating factor (PAF) (7.9) receptors. RO1138452 (10 pM-10 μM) added to cells concurrently with a fixed concentration of Taprostene (1 μM) prevents, in a concentration-dependent manner, the inhibition of CXCL9 and CXCL10 release, with p[A] ₅₀ (molar) values of -8.73±0.11 and -8.47±0.16 (p>0.05), respectively.

RO1138452 is a potent and selective antagonist for both human and rat IP receptors and that is possesses analgesic and anti-inflammatory potential. RO1138452 (1-10 mg/kg, i.v.) significantly reduces acetic acid-induced abdominal constrictions. RO1138452 (3-100 mg/kg, p.o.) significantly reduces carrageenan-induced mechanical hyperalgesia and edema formation. One hour after administration of RO1138452 (5 mg/kg, i.v.) to rats, the total plasma concentration is 0.189  μg/mL, whereas the free plasma concentrations is calculated to be 0.009 μg/mL (28 nM).