Features of α-Adrenergic Regulation of Isolated Rat Heart after Hypokinesia.

We studied the effect of the α-adrenergic receptor agonist clonidine hydrochloride (10-10 M) on the isolated heart of adult rats after 30-day restriction of motor activity. In hypokinetic rats, in comparison with control animals, clonidine caused a positive inotropic effect; the dynamics of coronary flow was changed after stimulation of α-adrenergic receptors by clonidine in the minimum and maximum concentrations. Moreover, clonidine in concentrations of 10 and 10 M reduced coronary flow both in the control group and against the background of hypokinesia.

Effect of α2-Adrenergic Receptor Stimulation on the Isolated Rat Heart against the Background of I Blockade.

The study examined the effect of α-adrenoreceptor (α-AR) activation against the background of preliminary blockage of I on the performance of Langerndorff-isolated rat heart. Stimulation of α-AR in isolated rat hearts against the background of ZD7288 in concentrations of 10 M and 3×10 M changed the negative dynamics of myocardial inotropy to positive (by 25 and 38%; p<0.05).