Lipid peroxidation and nitric oxide inactivation in postmenopausal women.
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.
Pereira
Isabela Rosier Olimpio
IR
Instituto Dante Pazzanese de Cardiologia, Faculdade de Ciências Farmacêuticas e Faculdade de Saudé Health, USP, Sao Paulo, SP, Brazil.
Bertolami
Marcelo Chiara
MC
Faludi
André Arpad
AA
Campos
Maria Fernanda
MF
Ferderbar
Simone
S
Lima
Emersom Silva
ES
Aldrighi
José Mendes
JM
Abdalla
Dulcineia Saes Parra
DS
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
D004967:Estrogens; D026403:S-Nitrosothiols; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D004958:Estradiol; D002784:Cholesterol