Phospholipase C Inhibitor Prevents the Effects of Methoxamine on the Action Potential of Cardiomyocytes in Rats of Different Ages

In the present study, we investigated the effect of α1-adrenergic receptor stimulation on the electrical activity of the right atrium cardiomyocytes with imposed rhythm in rats of different ages using methoxamine and methoxamine against the background of selective blockade of phospholipase C inhibitor (U-73122). Methoxamine increased the duration of the repolarization phase of the action potential. However, there were no changes in the other electrophysiological parameters studied. U-73122 markedly blocked all effects of α1-adrenoreceptor stimulation on the parameters of the electrical activity of working cardiomyocytes in 7-, 21-, and 100-day-old rats.