The powerful cardioprotective effects of urocortin and the corticotropin releasing hormone (CRH) family.

The urocortins are members of the corticotropin releasing hormone (CRH) family of peptide hormones. The archetypal member of this family, CRH, plays an important role in regulating thermogenesis and homeostasis by acting centrally and systemically in target organs via its two receptors CRH-R1 and CRH-R2. However, by virtue of their much greater relative affinity for CRH-R2, the physiological effects of the urocortin peptides are largely restricted to peripheral organs such as the heart. A powerful cytoprotective effect of urocortin peptide administration against ischemia and reperfusion injury has been demonstrated in isolated cardiomyocyte models, as well as in the intact heart both in vitro and in vivo. Extremely promising data has shown the beneficial effect of treating pacing-induced heart failure in sheep with urocortin molecules. Though the efficacy and specificity of these molecules in humans is not yet established, molecular dissection of the cytoprotective pathways activated by urocortin peptides suggests that the beneficial effects may be separable from potentially deleterious effects.