title: Ozone exposure induces iNOS expression and tyrosine nitration in rat aorta.
abstract: The aim was to study whether ozone affects vascular endothelium by causing inducible nitric oxide synthase (iNOS) expression and tyrosine nitration. We also studied biomarkers of endothelial function. Male Wistar rats were exposed to ozone (0.25ppm, 4h/day) or filtered air (control, ozone <0.05ppm). After ozone exposure, blood samples were taken to measure 6-keto prostaglandin F1α (6-keto PGF1α), dehydro-thromboxane B(2) (DH-TxB(2)), endothelin-1 and NO(2)(-)/NO(3)(-) (NO(x)(-)). iNOS and nitrotyrosine were detected in aorta by immunohistochemistry. Nitrotyrosine was also detected by immunoelectromicroscopy. Control aortae failed to show either iNOS or nitrotyrosine. Time-dependent positive iNOS and nitrotyrosine cells were observed in exposed animals. Except for NO(x)(-), endothelial markers decreased after 14 days of ozone exposure (P<0.05). After 28 days of ozone, 6-keto PGF1α remained low (P<0.05) while DH-TxB(2) increased (P<0.05). It is concluded that ozone causes endothelial dysfunction manifested early with peroxynitrite formation and lately with changes in endothelial markers.
authors.affiliation: Escuela Superior de Medicina del Instituto Politécnico Nacional, Mexico, Mexico; Escuela Médico Militar, Mexico.
authors.forename: Dolores J
authors.initials: DJ
authors.lastname: Sánchez-González
authors.forename: María A
authors.initials: MA
authors.lastname: Moro
authors.forename: Carlos
authors.initials: C
authors.lastname: Castillo-Henkel
authors.forename: Norma
authors.initials: N
authors.lastname: Herrera-González
authors.forename: Rogelio
authors.initials: R
authors.lastname: Hernández-Pando
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Larios-Medina
authors.forename: Rafael
authors.initials: R
authors.lastname: Cobilt
authors.forename: José A
authors.initials: JA
authors.lastname: Blanco
authors.forename: José
authors.initials: J
authors.lastname: Pedraza-Chaverrí
authors.forename: Cleva
authors.initials: C
authors.lastname: Villanueva