title: Effects of aspirin-like drugs on nitric oxide synthesis in rat vascular smooth muscle cells.
abstract: The purpose of this study was to investigate the effects of aspirin-like drugs on nitric oxide (NO) synthesis in rat vascular smooth muscle cells (VSMCs). We measured the accumulation of nitrite, a stable oxidation product of NO, and the expression of inducible NO synthase (iNOS) mRNA and protein in rat cultured VSMCs. Sodium salicylate, aspirin, and indomethacin dose-dependently enhanced nitrite production by interleukin (IL)-1beta-stimulated VSMCs at therapeutic plasma concentration ranges. Increased nitrite production by aspirin-like drugs was accompanied by increased iNOS mRNA and protein accumulation in VSMCs. Addition of IL-1beta activated nuclear factor kappaB (NF-kappaB) in VSMCs, but sodium salicylate did not affect IL-1beta-induced NF-kappaB activation. The nonselective lipoxygenase (LO) inhibitor nordihydroguaiaretic acid inhibited sodium salicylate-induced nitrite production, whereas the selective 5-LO inhibitor caffeic acid did not influence production of nitrite. The 12-LO product 12-HETE dose-dependently enhanced nitrite production by IL-1beta-stimulated VSMCs, whereas the 15-LO product 15-HETE did not. Our study demonstrates that aspirin and the aspirin-like drugs, sodium salicylate and indomethacin, increase NO synthesis in IL-1beta-stimulated VSMCs by upregulation of iNOS transcription via a 12-LO pathway. These effects were independent of NF-kappaB activation. In addition to the direct inhibition of platelet function, aspirin-like drugs may contribute to the reduction of atherothrombotic risk in myocardial ischemia via enhancing NO production by VSMCs.
authors.affiliation: Department of Cardiology, Jichi Medical School, Tochigi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shimpo
authors.forename: U
authors.initials: U
authors.lastname: Ikeda
authors.forename: Y
authors.initials: Y
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Ohya
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: K
authors.initials: K
authors.lastname: Shimada
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D051381:Rats; D017207:Rats, Sprague-Dawley; D012980:Sodium Salicylate / Q000494:pharmacology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D006893:Hydroxyeicosatetraenoic Acids; D009569:Nitric Oxide; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D001241:Aspirin; D012980:Sodium Salicylate; D007213:Indomethacin