A eritropoietina protege a função sistólica de corações neonatais submetidos a isquemia e reperfusão regional : trabalho experimental / Erythropoietin protects the systolic function of neonatal hearts against ischemiareperfusion injury

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

29/04/2012

RESUMO

Background: The effect of erythropoietin (EPOT) on neonatal hearts is not well understood. The current hypothesis is that erythropoietin has protective effects against ischemia-reperfusion when administered prior to ischemia induction. Methods: Systolic and diastolic indices, as well as the Akt and extracellular regulated kinase (ERK) signaling pathways, were studied in vivo using a neonatal pig heart model. Regional ischemia was induced for 45 min by ligation of the left anterior descending artery, followed by 90 min of reperfusion. The treatment groups consisted of: 1) untreated controls, 2) treatment with erythropoietin 3 min prior to ischemia, and 3) treatment with erythropoietin 24 h before ischemia. Sophisticated myocardial contractility indices were assessed by pressure/volume loops of the left ventricle. The Akt and ERK pathways were evaluated via western blot. Results: Elastance was found to be higher in the group receiving erythropoietin 3 min prior to ischemia. In addition, preload recruitable stroke work was higher for both groups receiving erythropoietin prior to ischemia when compared to controls. The time constant of the isovolumic relaxation and end diastolic pressure volume relationship did not differ between the three groups after 90 min of reperfusion. Furthermore, erythropoietin treatment enhanced phosphorylation of Akt, but not ERK, and erythropoietin treated animals showed lower levels of apoptosis-related proteins. Conclusions: Erythropoietin had a protective effect on neonatal systolic function after ischemia/reperfusion injury, but no effect on diastolic function. This cardioprotective effect might be mediated by activation of the Akt pathway.

ASSUNTO(S)

reperfusão miocárdica peptídeos e proteínas de sinalização intracelular precondicionamento isquêmico miocárdico coração - contração myocardial reperfusion intracellular signaling septides and proteins ischemic preconditioning myocardia myocardial contraction

ACESSO AO ARTIGO

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