Role of P2X receptors in positive inotropic effect of rat myocardium during ontogeny

Experiments with selective agonists and antagonists of purinoceptors allowed us to evaluate the subtype of P2X receptors. We showed that the myocardium of 14-100-day-old rats contains functionally active P2X 1 receptors. These receptors are involved in the realization of the positive inotropic effect of the atria and ventricles. Selective P2X 1 receptor agonist β,γ-methylene-ATP induced a dose-dependent increase in the strength of atrial and ventricular contractions. P2X 1 receptor antagonist TNP-ATP abolished the effect of the agonist in rats of all age groups. © Springer Science+Business Media, Inc. 2008