Urocortin 2 (Ucn2) is an endogenous peptide in the corticotrophin-releasing factor (CRF) family.[1] Immunohistochemistry analysis of human myocytes has shown greater immunoreactivity of Ucn2 in myocytes of the failing heart compared to those of the healthy heart. Researchers suggest this is a result of an innate mechanism in which Ucn2 acts to improve function of the failing heart [2]. The pathophysiology of heart failure is often a consequence of improper calcium handling and relaxation resulting in a lower cardiac output, decreased blood flow and overall decreased heart function [3]. Infusion of Ucn2 in healthy humans has shown a dose dependent increase in cardiac output, heart rate and left ventricle ejection fraction and a decrease in systemic vascular resistance [4]. Ucn2 has been studied as potential treatment for individuals with heart failure.

http://en.wikipedia.org/wiki/Urocortin_II