title: Inactivity of nitric oxide synthase gene in the atherosclerotic human carotid artery.
abstract: OBJECTIVE
  Nitric oxide (NO) inhibits thrombus formation, vascular contraction, and smooth muscle cell proliferation. We investigated whether NO release is enhanced after endothelial NO synthase (eNOS) gene transfer in atherosclerotic human carotid artery ex vivo.
  
  
  RESULTS
  Western blotting and immunohistochemistry revealed that transduction enhanced eNOS expression; however, neither nitrite production nor NO release measured by porphyrinic microsensor was altered. In contrast, transduction enhanced NO production in non-atherosclerotic rat aorta and human internal mammary artery. In transduced carotid artery, calcium-dependent eNOS activity was minimal and did not differ from control conditions. Vascular tetrahydrobiopterin concentrations did not differ between the experimental groups. Treatment of transduced carotid artery with FAD, FMN, NADPH, L-arginine, and either sepiapterin or tetrahydrobiopterin did not alter NO release. Superoxide formation was similar in transduced carotid artery and control. Treatment of transduced carotid artery with superoxide dismutase (SOD), PEG-SOD, PEG-catalase did not affect NO release.
  
  
  CONCLUSIONS
  eNOS transduction in atherosclerotic human carotid artery results in high expression without any measurable activity of the recombinant protein. The defect in the atherosclerotic vessels is neither caused by cofactor deficiency nor enhanced NO breakdown. Since angioplasty is performed in atherosclerotic arteries,eNOS gene therapy is unlikely to provide clinical benefit.
authors.affiliation: Cardiovascular Research, Physiology Institute University of Zürich, Zürich, Switzerland.
authors.forename: Felix C
authors.initials: FC
authors.lastname: Tanner
authors.forename: Bernd
authors.initials: B
authors.lastname: van der Loo
authors.forename: Sidney
authors.initials: S
authors.lastname: Shaw
authors.forename: Helen
authors.initials: H
authors.lastname: Greutert
authors.forename: Markus M
authors.initials: MM
authors.lastname: Bachschmid
authors.forename: Maria
authors.initials: M
authors.lastname: Berrozpe
authors.forename: Izabela
authors.initials: I
authors.lastname: Rozenberg
authors.forename: Nenad
authors.initials: N
authors.lastname: Blau
authors.forename: Robert
authors.initials: R
authors.lastname: Siebenmann
authors.forename: Jürg
authors.initials: J
authors.lastname: Schmidli
authors.forename: Peter
authors.initials: P
authors.lastname: Meyer
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Lüscher
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000368:Aged; D000818:Animals; D001011:Aorta / Q000201:enzymology / Q000378:metabolism; D050197:Atherosclerosis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002339:Carotid Arteries / Q000201:enzymology / Q000378:metabolism*; D002460:Cell Line; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000201:enzymology / Q000378:metabolism; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques; D014161:Transduction, Genetic
chemical_list: D013481:Superoxides; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III