Mechanisms of opioid delta (delta) and kappa ( kappa) receptors' cardioprotection in ischaemic preconditioning in a rat model of myocardial infarction.

It has been demonstrated that brief periods of coronary artery occlusion before a prolonged period of sustained occlusion paradoxically protect the myocardium against infarction. The mechanisms involved in this phenomenon, termed "ischaemic preconditioning" (IPC) are still not clear, although it has been established that opioid receptors are involved. The aim of this study was to probe some of the plausible mechanisms involved in the phenomenon by using an in vivo model of myocardial infarction in intact rat, a model that allows electro-cardiographic and enzymatic in addition to morphometric evaluation of the development of 24-hour myocardial infarction.

Involvement of opioid delta (delta)- and kappa (kappa)-receptors in ischemic preconditioning in a rat model of myocardial infarction.

There is controversy in the literature regarding the involvement of opioid delta (DOP, OP1)- and kappa (KOP,OP2)-receptors in ischemic preconditioning (IPC). Previous studies on this subject in our laboratories and elsewhere have been performed on either isolated heart muscles of experimental animals, or in open-heart surgery rats. To highlight this problem, we introduced an in vivo model of myocardial infarction in rats, which not only allowed electrocardiographic and enzymatic evaluation, but also morphometric assessment of myocardial infarction.