title: Effects of beta-adrenoceptor stimulation on endothelial nitric-oxide synthase phosphorylation of human umbilical vein endothelial cells.
abstract: OBJECTIVE
  To investigate the effects of isoprenaline on the phosphorylation level of endothelial nitric oxide synthase (eNOS) of human umbilical vein endothelial cells (HUVEC) and to elucidate the regulation mechanisms of beta-adrenoceptor (beta-AR) on eNOS activity.
  
  
  METHODS
  HUVEC were exposed to isoprenaline (1 micromol/L) for 30 min, in the absence or presence of selective beta1- or beta2 -adrenoceptor antagonists. eNOS was then isolated by immunoprecipitation using a specific eNOS antibody. eNOS activity was determined by the conversion of L-[3H]arginine to L-[3H]citrulline. The levels of eNOS expression and eNOS phosphorylation were measured by Western blotting.
  
  
  RESULTS
  Treatment of HUVEC with isoprenaline (1 micromol/L) for 30 min caused no measureable change in eNOS expression. However, eNOS activity and serine phosphorylation level were significantly increased (P<0.01). This effect could be abolished by a selective beta2-adrenoceptor antagonist ICI 118551.
  
  
  CONCLUSIONS
  Isoprenaline increases eNOS activity of HUVEC, this is mediated by beta2-adrenoceptor and associated with an increase of eNOS serine phosphorylation level.
authors.affiliation: Department of Cardiology, Affiliated Zhong Da Hospital of Southeast University, Nanjing 210009, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Yao
authors.forename: Biao
authors.initials: B
authors.lastname: Xu
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Liu
authors.forename: Albert
authors.initials: A
authors.lastname: Ferro
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000201:enzymology*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D010766:Phosphorylation; D011412:Propanolamines / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology / Q000201:enzymology
chemical_list: D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C026777:ICI 118551; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D007545:Isoproterenol