TY - JOUR T1 - Sphingosine 1-Phosphate Regulates Vascular Contraction via S1P<sub>3</sub> Receptor: Investigation Based on a New S1P<sub>3</sub> Receptor Antagonist JF - Molecular Pharmacology JO - Mol Pharmacol DO - 10.1124/mol.109.061481 SP - mol.109.061481 AU - Akira Murakami AU - Hiroshi Takasugi AU - Shinya Ohnuma AU - Yuuki Koide AU - Atsuko Sakurai AU - Satoshi Takeda AU - Takeshi Hasegawa AU - Jun Sasamori AU - Takashi Konno AU - Kenji Hayashi AU - Yoshiaki Watanabe AU - Koji Mori AU - Yoshimichi Sato AU - Atsuo Takahashi AU - Naoki Mochizuki AU - Nobuyuki Takakura Y1 - 2010/01/01 UR - http://molpharm.aspetjournals.org/content/early/2010/01/22/mol.109.061481.abstract N2 - Sphingosine 1-phosphate (S1P) induces diverse biological responses in various tissues by activating specific G protein-coupled receptors (S1P1-S1P5 receptors). The biological signaling regulated by S1P3 receptor has not been fully elucidated because of the lack of a S1P3 receptor-specific antagonist or agonist. We developed a novel S1P3 receptor antagonist, 1-(4-chlorophenylhydrazono)-1-(4-chlorophenylamino)-3,3-dimethyl-2-butanone (TY-52156), and show here that the S1P-induced decrease in coronary flow (CF) is mediated by S1P3 receptor. In functional studies, TY-52156 showed sub-micromolar potency and a high degree of selectivity for S1P3 receptor. TY-52156, but not an S1P1 receptor antagonist (VPC23019) or S1P2 receptor antagonist (JTE013), inhibited the decrease in CF induced by S1P in isolated perfused rat hearts. We further investigated the effect of TY-52156 on both the S1P-induced increase in intracellular calcium ([Ca2+]i) and Rho activation that are responsible for the contraction of human coronary artery smooth muscle cells. TY-52156 inhibited both the S1P-induced increase in [Ca2+]i and Rho activation. In contrast, VPC23019 and JTE013 inhibited only the increase in [Ca2+]i and Rho activation, respectively. We further confirmed that TY-52156 inhibited FTY-720-induced S1P3 receptor-mediated bradycardia in vivo. These results clearly show that TY-52156 is both sensitive and useful as a S1P3 receptor-specific antagonist, and reveal that S1P induces vasoconstriction by directly activating S1P3 receptor and through a subsequent increase in [Ca2+]i and Rho activation in vascular smooth muscle cells.The American Society for Pharmacology and Experimental Therapeutics ER -