ABSTRACT
Ischemic preconditioning has been defined as a tolerance of the myocardium to subsequent sustained ischemic damage after the heart was insulted one or more brief periods of ischemic stress. The cardioprotective effect of ischemic preconditioning may be mediated by endogenous cardiovascular active substances. Neurotransmitters, including catecholamines, acethylcholine, calci-tonin gene-related peptide and opioids, may be endogenous myocardial protective substances, and participate in the mediation of ischemic preconditioning. Exogenous administration of neurotrans-mitters can mimic the cardioprotective effect of ischemic preconditioning. There is interactions of some neurotransmitters with other endogenous active substances. The mechanism by which neurotransmitters are involved in the cardioprotective effect of ischemic preconditioning is thought to activate their corresponding receptors, with a subsequent triggering cellular signaling pathway, resulting in myocardial protection.