title: Relationships between NOS2 and HO-1 in liver of rats with chronic bile duct ligation.
abstract: An increased expression and activity of the heme oxygenase-1 (HO-1) in the liver has been observed in models of hepatic damage. Nitric oxide (NO) seems to be involved in HO-1 regulation. The aim of this work is to assess HO-1 induction and heme oxygenase (HO) activity in rats with bile duct ligation (BDL). We have assessed the effect of chronic inhibition of the NO synthesis by N(G)-nitro-l-arginine methyl ester (l-NAME) on HO-1 induction and HO activity. In the BDL animals, compared with sham-operated ones, we found an increased plasma nitrite and bilirubin concentration, and a marked liver expression of inducible nitric oxide synthase and HO-1, assessed by both Western blot and immunohistochemistry. Chronic l-NAME treatment prevented plasma nitrite increase in animals subjected to BDL. BDL animals treated with l-NAME, compared with untreated BDL rats, showed an important decrease in HO-1 expression and in HO activity (assessed as a decreased plasma bilirubin and bilirubin excretion). In conclusion, our experiments show parallel changes in expression and activity of HO-1 and NOS2 activity in the BDL model of liver damage and suggest that increased NO production is involved in HO-1 overexpression.
authors.affiliation: Department of Physiology and Pharmacology, Edificio Departamental, Campus Miguel de Unamuno, University of Salamanca, 37007 Salamanca, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Flores
authors.forename: Manuela
authors.initials: M
authors.lastname: Criado
authors.forename: Angel
authors.initials: A
authors.lastname: Sánchez-Rodríguez
authors.forename: Froilán
authors.initials: F
authors.lastname: Hidalgo
authors.forename: Francisco
authors.initials: F
authors.lastname: Collía
authors.forename: José Miguel
authors.initials: JM
authors.lastname: López-Novoa
authors.forename: Alejandro
authors.initials: A
authors.lastname: Esteller