Abstract
D-glucose infusion and gestational diabetes induce vasodilatation in humans and increase L-arginine transport and nitric oxide (NO) synthesis in human umbilical vein endothelial cells. High D-glucose (25 mmol/L, 2 minutes) induced membrane hyperpolarization and an increase of L-arginine transport (V(max) 6.1+/-0.7 versus 4.4+/-0.1 pmol/ microg protein per minute) with no change in transport affinity (K(m) 105+/-9 versus 111+/-16 micromol/L). L-[3H]citrulline formation and intracellular cGMP, but not intracellular Ca2+, were increased by high D-glucose. The effects of D-glucose were mimicked by levcromakalim (ATP-sensitive K+ channel blocker), paralleled by p42/p44(mapk) and Ser(1177)-endothelial NO synthase phosphorylation, inhibited by N(G)-nitro-L-arginine methyl ester (L-NAME; NO synthesis inhibitor), glibenclamide (ATP-sensitive K+ channel blocker), KT-5823 (protein kinase G inhibitor), PD-98059 (mitogen-activated protein kinase kinase 1/2 inhibitor), and wortmannin (phosphatidylinositol 3-kinase inhibitor), but they were unaffected by calphostin C (protein kinase C inhibitor). Elevated D-glucose did not alter superoxide dismutase activity. Our findings demonstrate that the human fetal endothelial L-arginine/NO signaling pathway is rapidly activated by elevated D-glucose via NO and p42/44(mapk). This could be determinant in pathologies in which rapid fluctuations of plasma D-glucose may occur and may underlie the reported vasodilatation in early stages of diabetes mellitus.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Transport Systems, Basic
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Arginine / metabolism*
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Arginine / pharmacokinetics
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Biological Transport / drug effects
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Cationic Amino Acid Transporter 1 / genetics
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Cationic Amino Acid Transporter 1 / metabolism
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Cationic Amino Acid Transporter 2 / genetics
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Cationic Amino Acid Transporter 2 / metabolism
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Cells, Cultured
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Endothelium, Vascular / cytology
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Endothelium, Vascular / drug effects
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Endothelium, Vascular / metabolism*
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Enzyme Inhibitors / pharmacology
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Glucose / pharmacology*
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Humans
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases / metabolism*
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Nitric Oxide / metabolism*
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Onium Compounds / pharmacokinetics
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Organophosphorus Compounds / pharmacokinetics
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Patch-Clamp Techniques
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Potassium Channel Blockers / pharmacology
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Protein Kinase C / metabolism
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RNA, Messenger / metabolism
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Signal Transduction / drug effects
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Signal Transduction / physiology
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Superoxide Dismutase / metabolism
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Umbilical Veins / cytology
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alpha-Tocopherol / pharmacology
Substances
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Amino Acid Transport Systems, Basic
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Cationic Amino Acid Transporter 1
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Cationic Amino Acid Transporter 2
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Enzyme Inhibitors
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Onium Compounds
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Organophosphorus Compounds
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Potassium Channel Blockers
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RNA, Messenger
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SLC7A1 protein, human
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SLC7A2 protein, human
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Nitric Oxide
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Arginine
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Superoxide Dismutase
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Protein Kinase C
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases
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alpha-Tocopherol
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Glucose
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tetraphenylphosphonium