RESUMEN
1. The vasodilator responses to 15(R)-15-methylprostaglandin E2 (arbaprostil), prostaglandin (PG) E2 and acetylcholine (ACh) administered into the femoral artery intra-arterial (i.a.) of anesthetized rats were attenuated by i.a. infusion of methylene blue, while that to nicardipine remained unaffected in the same dose-range of methylene blue. 2. The vasocontractor responses to arbaprostil and PGE2 in isolated femoral arterial strips were significantly potentiated by removal of the endothelium and the presence of NG-monomethyl L-arginine, while that to U-46619 remained unaffected under the same condition. 3. The present result indicates that the endothelium-dependent mechanism may play an important role in the vascular response to arbaprostil, like PGE2 and ACh.