A highly potent peptide analgesic that protects against ischemia-reperfusion-induced myocardial stunning.
Am J Physiol Heart Circ Physiol
; 283(2): H783-91, 2002 Aug.
Article
em En
| MEDLINE
| ID: mdl-12124228
ABSTRACT
We recently discovered an opioid peptide analgesic, 2',6'-dimethyltyrosine (Dmt)-D-Arg-Phe-Lys-NH(2) ([Dmt(1)]DALDA), that can protect against ischemia-induced myocardial stunning. In buffer-perfused hearts, 30-min global ischemia followed by reperfusion resulted in a significant increase in norepinephrine (NE) overflow immediately upon reperfusion and significant decline in contractile force (45%). Pretreatment with [Dmt(1)]DALDA before ischemia completely abolished myocardial stunning and significantly reduced NE overflow (68%). In contrast, pretreatment with morphine before ischemia only provided brief protection against myocardial stunning and no reduction in NE overflow. [Dmt(1)]DALDA inhibited [(3)H]NE uptake into cardiac synaptosomes in vitro (IC(50) = 3.9 microM), whereas morphine had no effect. Surprisingly, protection against myocardial stunning was apparent even when hearts were perfused with [Dmt(1)]DALDA only upon reperfusion, whereas reperfusion with morphine had no effect. Binding studies with [(3)H][Dmt(1)]DALDA revealed no high-affinity specific binding in cardiac membranes, suggesting that the cardioprotective actions of [Dmt(1)]DALDA are not mediated via opioid receptors. These findings suggest that [Dmt(1)]DALDA is a potent analgesic that may be useful for myocardial stunning resulting from cardiac interventions or myocardial ischemia.
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Base de dados:
MEDLINE
Assunto principal:
Oligopeptídeos
/
Traumatismo por Reperfusão Miocárdica
/
Isquemia Miocárdica
/
Miocárdio Atordoado
/
Analgésicos
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article