Na+/H+ exchanger inhibition at the onset of reperfusion decreases myocardial infarct size: role of reactive oxygen species.
Cardiovasc Pathol
; 15(4): 179-84, 2006.
Article
em En
| MEDLINE
| ID: mdl-16844548
ABSTRACT
BACKGROUND:
A burst of reactive oxygen species and activation of Na+/H+ exchanger take place at the beginning of reperfusion. The aim of this study was to assess the possible interrelation of the inhibition of Na+/H+ exchanger and reactive oxygen species about the determination of myocardial infarct size.METHODS:
Isolated rat hearts were submitted to 40 min of coronary occlusion and 2 h of reperfusion. Infarct size was determined through triphenyltetrazolium chloride staining technique and was expressed as a percentage of risk area. Lipid peroxidation, as a marker of oxidative stress, was estimated by the concentration of thiobarbituric reactive substances.RESULTS:
Treatment during the first 20 min of reperfusion with a selective inhibitor of Na+/H+ exchanger 1 isoform, HOE 642 (cariporide; 10 microM), significantly diminished infarct size (15.1+/-2.4% vs. 31+/-2% in untreated hearts). The administration of a "scavenger" of hydroxyl radical, N-(2-mercaptopropionyl)-glycine (2 mM), decreased infarct size in an extent similar to that of cariporide (18+/-3%). The combination cariporide+N-(2-mercaptopropionyl)-glycine did not produce additional protection (17+/-1.7%). Each intervention [HOE 642 or N-(2-mercaptopropionyl)-glycine] and its combination improved the postischemic recovery of myocardial systolic and diastolic functions in a similar extent. The content of the thiobarbituric reactive substances of untreated hearts (1012+/-144 nmol/g) decreased to 431+/-81, 390+/-82, and 433+/-41 after cariporide, N-(2-mercaptopropionyl)-glycine, and cariporide+N-(2-mercaptopropionyl)-glycine treatments, respectively.CONCLUSIONS:
The present data support the conclusion that the cardioprotective effect of cariporide is associated with diminution of oxidative stress.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sulfonas
/
Cardiotônicos
/
Traumatismo por Reperfusão Miocárdica
/
Trocadores de Sódio-Hidrogênio
/
Guanidinas
/
Coração
/
Infarto do Miocárdio
Limite:
Animals
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article