Interaction of opioid and sympathetic-adrenal systems in ischemic heart damage

The effect of D-Ala2-Leu5-Arg6-enkephalin on catecholamines excretion in urine, their content and monoamine oxidase activity in rats with acute myocardial ischemia, was studied. Enkephalins were found to promote the inhibition of unadequate hyperfunction of sympathetic-adrenal system at early stages of myocardial infarction and to favour the exhaustion prophylaxis of accumulated precursors of catecholamines biosynthesis. The above-mentioned effects are realized owing to peptidergic inhibition of enzymes that catalize dioxyphenylalanine and dopamine biotransformation to noradrenalin and adrenalin, with subsequent increase in dioxyphenylalanine synthesis. The effect of catecholamines is also achieved because of their ability to decrease release and to increase reverse neuronal seizure of monoamines that leads to maintenance and faster restoration of catecholamines' level in adrenergic structures in stress.