Abstract
In cultured vascular smooth muscle cells (VSMCs), interleukin-1beta (IL-1beta) stimulates inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production. IL-1beta also activates phospholipase A2 (PLA2), and induces lipoxygenase (LOX) and cyclooxygenase-2 (COX-2). The present study investigated whether these metabolites are involved in the regulation of IL-1beta-induced NO production and iNOS expression. Pretreatment with ONO-RS-082, the secretory PLA2 (sPLA2) inhibitor, at 1 to 10 micromol/l reduced IL-1beta-stimulated nitrite production and iNOS expression. Nordihydroguaiaretic acid (NDGA, 1 to 10 micromol/l), the LOX inhibitor, also reduced IL-1beta (10 ng/ml)-stimulated nitrite production and iNOS expression in a dose-dependent manner. Exogenous 12(S)-hydroxyeicosatetraenoic acids (HETE) enhanced the IL-1beta-stimulated nitrite production and iNOS expression. On the other hand, the COX inhibitors, indomethacin and NS-398, had little effect on nitrite production or iNOS expression. These results suggest that LOX products play important roles in the regulation of stimulus-induced NO production in VSMCs.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aminobenzoates / pharmacology
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Animals
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Aorta, Thoracic / cytology
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Cells, Cultured
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Chlorobenzoates
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Cinnamates / pharmacology
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Cyclooxygenase Inhibitors / pharmacology
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Flavanones*
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Flavonoids / pharmacology
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Group II Phospholipases A2
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Interleukin-1 / pharmacology*
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Lipoxygenase / metabolism*
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Lipoxygenase Inhibitors / pharmacology
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Male
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Masoprocol / pharmacology
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Muscle, Smooth, Vascular / cytology
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Muscle, Smooth, Vascular / drug effects
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Muscle, Smooth, Vascular / enzymology*
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Nitric Oxide / metabolism*
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Nitric Oxide Synthase / metabolism*
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Nitric Oxide Synthase Type II
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Phosphodiesterase Inhibitors / pharmacology
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Phospholipases A / antagonists & inhibitors
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Phospholipases A / metabolism
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Phospholipases A2
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Rats
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Rats, Wistar
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ortho-Aminobenzoates
Substances
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Aminobenzoates
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Chlorobenzoates
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Cinnamates
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Cyclooxygenase Inhibitors
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Flavanones
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Flavonoids
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Interleukin-1
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Lipoxygenase Inhibitors
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Phosphodiesterase Inhibitors
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ortho-Aminobenzoates
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Nitric Oxide
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baicalein
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Masoprocol
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2-(4-amylcinnamoyl)amino-4-chlorobenzoic acid
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Lipoxygenase
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Nitric Oxide Synthase
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Nitric Oxide Synthase Type II
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Nos2 protein, rat
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Phospholipases A
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Group II Phospholipases A2
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Phospholipases A2