COMPARATIVE-STUDIES WITH 15(R)-15-METHYLPROSTAGLANDIN-E2 (ARBAPROSTIL) IN RAT FEMORAL ARTERIAL PREPARATIONS IN-VIVO AND IN-VITRO

1. The vasodilator responses to 15(R)-15-methylprostaglandin E2 (arbap rostil), prostaglandin (PG) E2 and acetylcholine (ACh) administered in to the femoral artery intra-arterially (i.a.) of anesthetized rats wer e attenuated by i.a. infusion of methylene blue, while that to nicardi pine remained unaffected in the same dose-range of methylene blue. 2. The vasocontractor responses to arbaprostil and PGE2 in isolated femor al arterial strips were significantly potentiated by removal of the en dothelium and the presence of N(G)-monomethyl L-arginine, while that t o 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.