Journal of molecular and cellular cardiology
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J. Mol. Cell. Cardiol. · Aug 1997
Comparative StudyIschemic preconditioning and morphine-induced cardioprotection involve the delta (delta)-opioid receptor in the intact rat heart.
Several investigators have demonstrated that the opioid pathway is involved in tissue preservation during hypoxia or ischemia and that this protection is mediated via the delta (delta)-opioid receptor. Subsequently, we have shown that opioid receptors are involved in ischemic preconditioning (PC) in the rat heart and that morphine produces a cardioprotective effect; however, the class of opioid receptors involved in mediating these effects is still unknown. Therefore, the purpose of the present study was to test the hypothesis that ischemia- and morphine-induced cardioprotection are mediated via stimulation of the delta-opioid receptor in the rat heart. ⋯ Ischemic PC and morphine infusions resulted in similar reductions in IS/AAR from 51+/-4 to 11+/-3 and 15+/-4% (*P<0.05), respectively. NTI completely abolished the cardioprotective effect induced by ischemia and morphine. The results of the present study suggests a role of delta;-opioid receptors in ischemic PC or morphine-induced myocardial protection in the rat.