title: Lipid peroxidation and nitric oxide inactivation in postmenopausal women.
abstract: OBJECTIVE
  To assess the effect of endogenous estrogens on the bioavailability of nitric oxide (.NO) and in the formation of lipid peroxidation products in pre- and postmenopausal women.
  
  
  METHODS
  NOx and S-nitrosothiols were determined by gaseous phase chemiluminescence, nitrotyrosine was determined by ELISA, COx (cholesterol oxides) by gas chromatography, and cholesteryl linoleate hydroperoxides (CE18:2-OOH), trilinolein (TG18:2-OOH), and phospholipids (PC-OOH) by HPLC in samples of plasma.
  
  
  RESULTS
  The concentrations of NOx, nitrotyrosine, COx, CE18:2-OOH, and PC-OOH were higher in the postmenopausal period (33.8+/-22.3 microL; 230+/-130 nM; 55+/-19 ng/microL; 17+/-8.7 nM; 2775+/-460 nM, respectively) as compared with those in the premenopausal period (21.1+/-7.3 microM; 114+/-41 nM; 31+/-13 ng/microL; 6+/-1.4 nM; 1635+/-373 nM). In contrast, the concentration of S-nitrosothiols was lower in the postmenopausal period (91+/-55 nM) as compared with that in the premenopausal p in the premenopausal period (237+/-197 nM).
  
  
  CONCLUSIONS
  In the postmenopausal period, an increase in nitrotyrosine and a reduction of S-nitrosothiol formation, as well as an increase of COx, CE18:2-OOH and PC-OOH formation occurs. Therefore, NO inactivation and the increase in lipid peroxidation may contribute to endothelial dysfunction and to the greater risk for atherosclerosis in postmenopausal women.
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, Faculdade de Ciências Farmacêuticas e Faculdade de Saudé Health, USP, Sao Paulo, SP, Brazil.
authors.forename: Isabela Rosier Olimpio
authors.initials: IR
authors.lastname: Pereira
authors.forename: Marcelo Chiara
authors.initials: MC
authors.lastname: Bertolami
authors.forename: André Arpad
authors.initials: AA
authors.lastname: Faludi
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Campos
authors.forename: Simone
authors.initials: S
authors.lastname: Ferderbar
authors.forename: Emersom Silva
authors.initials: ES
authors.lastname: Lima
authors.forename: José Mendes
authors.initials: JM
authors.lastname: Aldrighi
authors.forename: Dulcineia Saes Parra
authors.initials: DS
authors.lastname: Abdalla
mesh_terms: D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000209:etiology; D002784:Cholesterol / Q000097:blood; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000502:physiology*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism*; D017698:Postmenopause / Q000097:blood / Q000378:metabolism*; D017697:Premenopause / Q000097:blood / Q000378:metabolism; D026403:S-Nitrosothiols / Q000097:blood; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood; D014664:Vasodilation
chemical_list: D004967:Estrogens; D026403:S-Nitrosothiols; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D004958:Estradiol; D002784:Cholesterol