Cirrhotic patients with minimal hepatic encephalopathy have increased capacity to eliminate superoxide and peroxynitrite in lymphocytes, associated with cognitive impairment

Autores de CIPF

• Carla Gimenez Garzó

  Autor

• 

  Amparo Urios Lluch

  Autor

• Ana Agustí Feliu

  Autor

• Raquel García García

  Autor

• 

  Vicente Felipo Orts

  Autor

• Carmina Montoliu Felix

  Autor

Participantes ajenos a CIPF

• Mangas-Losada, A
• Escudero-Garcia, D
• Kosenko, E
• Ordono, JF
• Tosca, J
• Giner-Duran, R
• Serra, MA

Grupos de Investigación

• Laboratorio de Neurobiología

  

  Jefe/a de Grupo

  Vicente Felipo Orts

• Unidad Mixta CIPF-INCLIVA de Deterioro Neurológico

Abstract

Patients with minimal hepatic encephalopathy (MHE) show increased oxidative stress in blood. We aimed to assess whether MHE patients show alterations in different types of blood cells in (a) basal reactive oxygen and nitrogen species levels; (b) capacity to metabolise these species. To assess the mechanisms involved in the altered capacity to metabolise these species we also analysed: (c) peroxynitrite formation and d) peroxynitrite reaction with biological molecules. Levels of reactive oxygen and nitrogen species were measured by flow cytometry in blood cell populations from cirrhotic patients with and without MHE and controls, under basal conditions and after adding generators of superoxide (plumbagin) or nitric oxide (NOR-1) to assess the capacity to eliminate them. Under basal conditions, MHE patients show reduced superoxide and peroxynitrite levels and increased nitric oxide (NO) and nitrotyrosine levels. In patients without MHE plumbagin strongly increases cellular superoxide, moderately peroxynitrite and reduces NO levels. In MHE patients, plumbagin increases slightly superoxide and strongly peroxynitrite levels and affects slightly NO levels. NOR-1 increases NO levels much less in patients with than without MHE. These data show that the mechanisms and the capacity to eliminate cellular superoxide, NO and peroxynitrite are enhanced in MHE patients. Superoxide elimination is enhanced through reaction with NO to form peroxynitrite which, in turn, is eliminated by enhanced reaction with biological molecules, which could contribute to cognitive impairment in MHE. The data show that basal free radical levels do not reflect the oxidative stress status in MHE.

Keywords

• Free radicals; nitric oxide; Psychometric Hepatic Encephalopathy Score; cognitive impairment; nitrotyrosine