Sphingosylphosphorylcholine induces cytosolic Ca(2+) elevation in endothelial cells in situ and causes endothelium-dependent relaxation through nitric oxide production in bovine coronary artery

• Published in: FEBS letters 1999-09, Vol.457 (3), p.375-380
• Main Authors: Mogami, K, Mizukami, Y, Todoroki-Ikeda, N, Ohmura, M, Yoshida, K, Miwa, S, Matsuzaki, M, Matsuda, M, Kobayashi, S
• Format: Article
• Language: English
• Subjects: Animals; Calcium - metabolism; Calcium Signaling; Cattle; Coronary Vessels - drug effects; Coronary Vessels - physiology; Cytosol - drug effects; Cytosol - metabolism; Endothelium, Vascular - drug effects; Endothelium, Vascular - metabolism; Enzyme Inhibitors - pharmacology; In Vitro Techniques; Nitric Oxide - metabolism; Nitric Oxide Synthase - antagonists & inhibitors; Nitric Oxide Synthase Type II; omega-N-Methylarginine - pharmacology; Phosphorylcholine - analogs & derivatives; Phosphorylcholine - metabolism; Phosphorylcholine - pharmacology; Polymethacrylic Acids - pharmacology; Sphingosine - analogs & derivatives; Sphingosine - metabolism; Sphingosine - pharmacology; Vasodilation - drug effects
• ISSN: 0014-5793
• DOI: 10.1016/S0014-5793(99)01076-5

Sphingosylphosphorylcholine (SPC) increased intracellular Ca(2+) concentration ([Ca(2+)]i) and nitric oxide (NO) production in endothelial cells in situ on bovine aortic valves, and induced endothelium-dependent relaxation of bovine coronary arteries precontracted with U-46619. The SPC-induced vasorelaxation was inhibited by N(omega)-monomethyl-L-arginine, an inhibitor of both constitutive and inducible NO synthase (NOS), but not by 1-(2-trifluoromethylphenyl) imidazole, an inhibitor of inducible NOS (iNOS). Immunoblotting revealed that endothelial constitutive NOS, but not iNOS, was present in endothelial cells in situ on the bovine aortic valves. We propose that SPC activates [Ca(2+)]i levels and NO production of endothelial cells in situ, thereby causing an endothelium-dependent vasorelaxation.