The Cardioprotective Peptide, Urocortin, Activates Cardiac KATP Channels in Adult Rat.

Urocortin (UCN), an endogenous cardioprotective peptide, has been reported to activate several ion channels but its effects on the cardiac KATP channels are unknown. In this paper, we showed that adult rat cardiac myocytes had small KATP currents that could be increased 20-fold by pinacidil. UCN also concentration-dependently activated the KATP current and this effect was influenced by ATP and PKA inhibitor peptide, Rp-cAMPS.