OPC-28326 is a selective peripheral vasodilator and an angatonist of α2-adrenergic receptor, with K_i of 2040, 285, and 55 nM for α2A-, α2B- and α2C-adrenoceptors, respectively. IC50 & Target: Ki: 2040 nM (α2A adrenoceptor), 285 nM (α2B adrenoceptor), 55 nM (α2C adrenoceptor)^[2] In Vitro: OPC-28326 enhances endothelial tube formation and promotes microvessel growth. OPC-28326 induces phosphorylation of eNOS and Akt in HAECs in a dose dependent-manner, while it does not affect total amounts of eNOS and Akt^[1]. OPC-28326 (1-100 μM) and yohimbine (10-1000 nM) causes a rightward shift in the concentration-response curve of clonidine^[2]. In Vivo: OPC-28326 augments blood flow recovery in murine hindlimb ischemia. OPC-28326 significantly increases the number of histologically detectable capillaries in the ischemic leg. OPC-28326 has no beneficial effects on blood flow recovery in eNOS−/− mice^[1]. OPC-28326 (3-30 mg/kg, i.v.) and yohimbine causes dose-dependent rightward shift in the pressor dose-response curve induced by B-HT 920. OPC-28326 does not affect on the mydriasis in rats^[2].