Orally active, selective vasopressin V1b receptor antagonist in vitro and in vivo.

SSR149415 is an orally active, selective vasopressin V1b receptor antagonist (human/rat Ki in nM = 1.5/1.3/V1b, 91/1050/V1a, 1412/2897/V2, 174/270/OT) that inhibits 30 nM AVP-induced Ca2+ response in human and rat V1b CHO transfectants (Ki = 1.26/2.0 nM). SSR149415 suppresses AVP-mediated physiological responses in vivo, including corticotropin secretion (1-30 mg/kg p.o. or i.p. in rats) upon exogenous AVP administration (0.3 µg/kg alone or 0.03 µg/kg with 0.1 µg corticoliberin/kg via i.v.), restraint stress-Induced corticotropin secretion (EC50 = 10 mg/kg i.p. in rats), and in a murine model of anxiety (four-plate test; 1-10 mg/kg i.p. or 3-10 mg/kg p.o. acute or 10 mg/kg/day p.o.).