Hypoxia causes downregulation of protein and RNA synthesis in noncontracting Mammalian cardiomyocytes.
Circ Res
; 90(7): 777-83, 2002 Apr 19.
Article
em En
| MEDLINE
| ID: mdl-11964370
ABSTRACT
The aim was to identify energy-consuming processes, other than contraction, downregulated during moderate hypoxia ( approximately 5 micromol/L, 0.5% O(2)) and severe hypoxia (<0.5 micromol/L, <0.05% O(2)) in isolated neonatal cardiomyocytes. The metabolic response of cardiomyocytes to moderate and severe hypoxia was assessed by measuring rates of energy consumption and energetic status of cells maintained under these conditions. We found that the rates of energy production were decreased during both forms of hypoxia. Decreased rates of energy production under moderate hypoxia were associated with reduced energy wastage through a downregulation of proton leak in the mitochondria. Cellular protein synthesis and RNA synthesis, major energy-consuming pathways, were downregulated only during severe hypoxia, when oxygen concentrations were low enough to induce energetic stress (quantitatively defined as being any situation in which phosphocreatine concentrations had fallen by > or = 40%). Our results suggest that energetic stress is the signal responsible for this downregulation.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA
/
Proteínas
/
Hipóxia Celular
/
Regulação para Baixo
/
Miocárdio
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Circ Res
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Austrália
País de publicação:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA