Effect of exogenous ATP on cardiac activity in rats

Abstract

In vivo effects of exogenous ATP on cardiac activity were studied on adult rats. Intravenous administration of ATP produced a positive chronotropic effect, but did not affect the stroke volume. This was due to activation of type II purine receptors, rather than due to the influence of ATP hydrolysis products, since P1 receptor agonist adenosine was ineffective. The blockade of beta-adrenoceptors and muscarinic receptors did not modify the positive chronotropic effect of ATP, which indicated that this action was not realized via sympathetic or parasympathetic nerves. ATP applied against the background of atropine blockade produced a 4-fold increase in the variability of heart rate typical of activation of the parasympathetic myocardial regulation.

Changes in Cardiac Tone Regulation with Fatigue after Supra-Maximal Running Exercise

“…By using magnetic resonance techniques, Pluim et al [34] showed that heart rate variability is significantly correlated with high-energy phosphate metabolism in trained and sedentary subjects. In fact, intravenous administration of ATP produced a 4-fold increase in the variability of heart rate typically indicating an activation of the parasympathetic myocardial regulation [35]. Therefore, an extra energy cost of skeletal muscle to the detriment of cardiac activity or a disruption of sarcolemmal ATP-sensitive K + channels [36] induced by supramaximal exercise may provoke a delayed cardiac tone response.…”

Role of Purinoceptors in Cardiac Function in Rats during Ontogeny

“…Previous experiments showed that intravenous infusion of ATP produces a positive chronotropic effect on the heart, but does not change stroke volume (SV). This effect is associated with activation of P2 purinoceptors, but not with the influence of products formed during ATP hydrolysis, because P1 receptor agonist adenosine was ineffective [1].…”