Study of reactive oxygen species (ROS) and nitric oxide (NO) as molecular mediators of the sepsis-induced diaphragmatic contractile dysfunction : protective effect of heme oxygenases

Barreiro Portela, Esther

Study of reactive oxygen species (ROS) and nitric oxide (NO) as molecular mediators of the sepsis-induced diaphragmatic contractile dysfunction : protective effect of heme oxygenases

Document Type

Doctoral thesis
Published Version

Author

Barreiro Portela, Esther

Director

Hussain, Saabah N.A.

Tutor

Gea Guiral, Joaquim

Publication Date

2002-06-18

Citation

Barreiro Portela, E. Study of reactive oxygen species (ROS) and nitric oxide (NO) as molecular mediators of the sepsis-induced diaphragmatic contractile dysfunction : protective effect of heme oxygenases. Universitat Pompeu Fabra; 2002. handle: http://hdl.handle.net/10803/7066

This citation was generated automatically.

Doctoral program

Programa de doctorat en Biomedicina

Abstract

Protein nitration is considered as a marker of reactive nitrogen species formation. Heme oxygenases (HOs) are important for the defence against oxidative stress. We evaluated the involvement of the neuronal (nNOS), the endothelial (eNOS), and the inducible (iNOS) in nitrotyrosine formation and localitzation, and both the expression and funcional significance (HO inhibition and contractility studies) of HOs in sepsis-induced muscle contractile dysfunction. Sepsis was elicited by injecting rats and transgenic mice deficient in either nNOS, eNOS, or iNOS isoforms with E.Coli lipolysaccharide (LPS). Nitrotyrosine formation and HO expressions were assessed by immunoblotting. Oxidative stress was assessed measuring protein oxidation, lipid peroxidation, and muscle glutathione. We conclude that protein tyrosine nitration occurs in normal muscles, and sepsis-mediated increase in nitrotyrosine formation is limited to the mitochondria and membrane muscle fractions. The iNOS isoform is mostly involved in nitrotyrosine formation. HOs protect normal and septic muscles from the deleterious effects of oxidants.
En un model de sepsi de disfunció diafragmàtica, s´ha avaluat el paper de les sintetases de l'òxid nítric (NOS) en la formació i localitzacio de 3-nitrotirosina, i l´expressió i significat biològic de les hemo oxigenases (HOs) (inhibidor de les HOs i estudis de contractilitat) davant l' estrès oxidatiu. La sepsi s'induí mitjançant injecció de 20 mg/kg del lipolisacàrid (LPS) d´Escherichia Coli a rates, i a ratolins deficients en les NOS induïble (iNOS), neuronal (nNOS) i endotelial (eNOS). Les proteïnes nitrificades i les HOs es van detectar amb anticossos específics. L' estrès oxidatiu s' avaluà mitjançant l' oxidació proteica, la peroxidació lipídica i el glutation muscular. Concloem que hi han proteïnes nitrificades en el múscul normal i aquestes s'incrementen durant la sepsi en les fraccions mitocondrial i membranar. L'isoforma iNOS és majorment responsable de la formació de nitrotirosina. Les HOs protegirien el múscul normal i sèptic dels efectes deleteris dels oxidants.

Keywords

neuronal (nNOS), endothelial (eNOS), inducible (iNOS), 3-Nitrotyrosine, Heme oxygenases (HOs). Sepsi, Músculs respiratoris, Espècies oxigenades reactives (ROS), Estrès oxidatiu, Òxid nítric (NO), sintetases del NO (NOS), neuronal (nNOS), endotelial (eNOS), induïble (iNOS), 3-nitrotirosina, Hemo-oxigenases (HOs), NO synthases (NOS), Nitric oxide (NO), Oxidative stress, Reactive oxygen species (ROS), Respiratory muscles, Sepsis