Response of Isolated Rat Heart to α2-Adrenergic Receptor Stimulation after If Current Blockade in the Late Postinfarction Period.

We studied the effect of α2-adrenoreceptor activation after preliminary If-current blockade on the performance of the Langendorff-isolated rat heart 54 days after modeling myocardial infarction. Stimulation of α2-adrenoreceptors against the background of application of If blocker ZD7288 in concentrations of 10-9 and 10-5 M decreased myocardial inotropy in isolated rat hearts by 50 and 39% (p<0.05) and increased HR by 20 and 15% (p<0.05), respectively. Activation of α2-adrenoreceptors against the background of application of ZD7288 in a concentration of 10-9 and 10-5 M led to a decrease in the coronary flow in the isolated rat heart with the model of myocardial infarction by 21% (p<0.05) and 32% (p<0.05), respectively.