Effects of adrenomedullin on the cardiac performance and coronary flow in an isolated perfused rat heart model

The effect of adrenomedullin (AM) on the cardiac performance and coronary f low were studied in an isolated perfused rat heart model based on the modif ied Langendorff method. The heart rate (HR), electrocardiogram (ECG), left ventricular contraction (LVC) (dP/dt), and coronary flow (CF) were measured before and after the application of AM. The effect of AM on the coronary f low was examined in the model with and without endothelial degradation, usi ng different inhibitors such as N-G-nitro-L-arginine, glibenclamide, and in domethacin. The present results indicated that AM increased HR and CF, but decreased LVC significantly, while it had no effect on EGG. The vasodilator y effect of AM was discussed in views of endothelial-dependence due to nitr ic oxide and K+ channel activation.