OPC-28326, a selective femoral arterial vasodilator, augments ischemia induced angiogenesis

OPC-28326, 4-(N-methyl-2-phenylethylamino)-1-(3,5-dimethyl-4-propionyl-aminobenzoyl) piperidine hydrochloride monohydrate, is a newly developed selective peripheral vasodilator and increases blood flow to lower extremities with alpha2-adrenergic antagonist property. Here, we investigated the effect of OPC-28326 on ischemia-induced angiogenesis. OPC-28326 enhanced tube formation by human aortic endothelial cells (HAECs). Moreover, OPC-28326 enhanced the number of microvessels sprouting from aortic rings embedded in collagen gel. OPC-28326 markedly induced phosphorylation of endothelial nitric oxide synthase (eNOS) in HAECs via phosphatidylinositol-3 kinase PI3K/Akt (PI3K/Akt) pathway. Next, the angiogenic effect of OPC-28326 was evaluated in a mouse hindlimb ischemia model. Blood flow recovery to the ischemic leg was significantly enhanced by OPC-28326. Furthermore, anti-CD31 immunostaining revealed that OPC-28326 increased capillary density in the ischemic muscle. However, OPC-28326 failed to promote blood flow recovery in ischemic hindlimb in eNOS-deficient mice. These results suggest that OPC-28326 promotes angiogenesis, which was associated with activation of eNOS via PI3K/Akt pathway. OPC-28326 might be promising to treat patients with ischemic vascular diseases.