title: Endothelial nitric oxide synthase expression in postmenopausal women: a sex-specific risk factor in coronary surgery.
abstract: BACKGROUND
  After coronary artery bypass graft surgery, older women have less favorable clinical outcome and lower conduit patency compared with men. This less favorable outcome can be in part ascribed to impaired endothelium-derived nitric oxide (eNOS) production. This study evaluated endothelial nitric oxide synthase expression in internal mammary artery from postmenopausal women undergoing coronary artery bypass graft surgery.
  
  
  METHODS
  Internal mammary artery segments were obtained from 20 postmenopausal woman and 20 matched male patients. Twenty more segments from younger patients were used as controls. Expression of eNOS messenger RNA in internal mammary artery endothelial cells were evaluated by polymerase chain reaction and real-time quantitative reverse transcription polymerase chain reaction. The eNOS protein level was assayed by Western blot. Vascular dynamics of specimens were evaluated by organ chamber methodology.
  
  
  RESULTS
  In postmenopausal women, the band of messenger RNA for eNOS was reduced by 37.4% and by 25.2%, respectively, compared with matched men and the control group (62.6%±4.8% versus 74.8%±5.3%, p<0.001). In comparison with the control group lane, the eNOS protein immunoreactive band was 44.2% decreased in postmenopausal women and 34.5% decreased in matched men, and was significantly decreased in postmenopausal women as compared with matched men (55.8%±4.6% versus 65.5%±5.2%, p<0.001). Nitric oxide-mediated vasomotor dynamics were consistent with reduced eNOS production.
  
  
  CONCLUSIONS
  Internal mammary artery endothelial cells from women after menopause undergoing coronary surgery have impaired expression of messenger RNA for eNOS and reduced eNOS levels. Reduced bioactivity of nitric oxide translates into impaired endothelial metabolism that could contribute to worse surgical outcome.
authors.affiliation: Department of Cardiac Surgery, University of Naples Federico II, and Department of Cardiology, Azienda Ospedaliera Santobono-Pausillipon, Naples, Italy. vitomannacio2@libero.it
authors.forename: Vito
authors.initials: V
authors.lastname: Mannacio
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Tommaso
authors.forename: Anita
authors.initials: A
authors.lastname: Antignano
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Amicis
authors.forename: Paolo
authors.initials: P
authors.lastname: Stassano
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Pinna
authors.forename: Carlo
authors.initials: C
authors.lastname: Vosa
mesh_terms: D000328:Adult; D000367:Age Factors; D015153:Blotting, Western; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000235:genetics* / Q000601:surgery; D004730:Endothelium, Vascular / Q000201:enzymology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008323:Mammary Arteries / Q000201:enzymology* / Q000503:physiopathology / Q000637:transplantation; D008875:Middle Aged; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis / Q000235:genetics*; D017698:Postmenopause / Q000097:blood*; D011183:Postoperative Complications; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D014664:Vasodilation / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D052250:Nitric Oxide Synthase Type III