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

We studied the effect of selective alpha(2C)-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 alpha(2)-adrenergic receptors in the regulation of activity of isolated adult rats heart.

Automated summary

We studied the effects of selective alpha(2C)-adrenergic receptor antagonist JP-1302 on inotropy, chronotropy, and coronary flow in isolated rat hearts. The results showed that JP-1302 decreased left-ventricular myocardium force contraction, heart rate, and coronary flow at all concentrations tested. The maximum effects were observed at a concentration of 10(-7) M, while the effects were least pronounced at concentrations of 10(-8) and 10(-9) M. These findings suggest that this subtype of alpha(2)-adrenergic receptors plays a role in regulating the activity of isolated adult rat hearts.