Influence Of Urocortin On Cardiac Remodeling And Function Of Mesenteric Artery In Rats

BACKGROUNDUrocortin (UCN), a 40-amino acid peptide, has 45% structural homology with the peptide corticotropin-releasing factor (CRF). Imunoreactivity of UCN is widely observed in central nervous, digestive, cardiovascular, reproductive, immune, endocrine systems. These facts suggest that UCN has important physiological roles in various tissues. In addition to pituitary and central effects as neurotransmitters, peripheral effects of CRF-related peptides have been reported, particularly in cardiovascular system.In cardiac system, it has been demonstrated that UCN could protect neonatal rat cardiac myocytes in vitro when administered before hypoxia or at the point of reoxygenation and protect the adult rat heart ex vivo where UCN reduced the infarct size of a perfused intact rat heart exposed to regional ischemia, which was confirmed by our recent in vivo study. Furthermore, a number of studies have implied that the mitogen-activated protein kinase (MAPK) acts as a survival pathway in cardiac cells and other cell types, which is one of the cardioprotective mechanisms of UCN effects. On the other hand, in normal mice and rats, intravenous administration of UCN caused increases in cardiac contractility.In vasculature, UCN binds with high affinity to CRF type 2 receptors,...