α2C-Adrenergic Receptor Blockade Inhibits Langendorff-Isolated Rat Heart Work.

ABSTRACT

We studied the effect of selective α2C-adrenergic receptor antagonist JP-1302 in concentrations of 10-9-10-6 M on inotropy, chronotropy, and coronary flow in the Langendorff-isolated rat heart. JP-1302 in all studied concentrations decreased the left-ventricular myocardium force contraction, HR, and coronary flow. The maximum inotropic, chronotropic, and vascular effects were observed when the antagonist was applied to the perfused solution in a concentration of 10-7 M. The least pronounced decrease in the studied parameters was observed at JP-1302 concentrations of 10-8 and 10-9 M. The obtained data indicate the participation of this subtype of α2-adrenergic receptors in the regulation of activity of isolated adult rats heart.