title: Rapid stimulation of L-arginine transport by D-glucose involves p42/44(mapk) and nitric oxide in human umbilical vein endothelium.
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.
authors.affiliation: Cellular and Molecular Physiology Laboratory, Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Flores
authors.forename: Susana
authors.initials: S
authors.lastname: Rojas
authors.forename: Claudio
authors.initials: C
authors.lastname: Aguayo
authors.forename: Jorge
authors.initials: J
authors.lastname: Parodi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mann
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Pearson
authors.forename: Paola
authors.initials: P
authors.lastname: Casanello
authors.forename: Luis
authors.initials: L
authors.lastname: Sobrevia
mesh_terms: D026923:Amino Acid Transport Systems, Basic; D001120:Arginine / Q000378:metabolism* / Q000493:pharmacokinetics; D001692:Biological Transport / Q000187:drug effects; D027201:Cationic Amino Acid Transporter 1 / Q000235:genetics / Q000378:metabolism; D027202:Cationic Amino Acid Transporter 2 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D009861:Onium Compounds / Q000493:pharmacokinetics; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013482:Superoxide Dismutase / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology; D024502:alpha-Tocopherol / Q000494:pharmacology
chemical_list: D026923:Amino Acid Transport Systems, Basic; D027201:Cationic Amino Acid Transporter 1; D027202:Cationic Amino Acid Transporter 2; D004791:Enzyme Inhibitors; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D026902:Potassium Channel Blockers; D012333:RNA, Messenger; C420825:SLC7A1 protein, human; C414177:SLC7A2 protein, human; D009569:Nitric Oxide; D001120:Arginine; D013482:Superoxide Dismutase; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D024502:alpha-Tocopherol; D005947:Glucose; C013289:tetraphenylphosphonium