Ghrelin As a Treatment for Cardiovascular Diseases

G hrelin, a growth hormone-releasing peptide that was first discovered in the stomach of rats in 1999, is an endogenous ligand of growth hormone secretagogue receptors (GHSRs). 1 Through binding to its receptors in the brain, ghrelin was initially shown to strongly stimulate the release of growth hormone and promote food intake. 2 Subsequent studies revealed that GHSRs are expressed ubiquitously in many organs and tissues, and ghrelin functionally participates in the regulation of diverse processes including appetite control, energy balance, body weight maintenance, glucose and fat metabolism, cell proliferation, and apoptosis, as well as the modulation of gastrointestinal, cardiovascular, pulmonary, and immune functions. The primary receptor of ghrelin is currently thought to be GHSR1a; however, other unidentified receptors might exist. The high expression of GHSR1a in the heart and large vessels provides evidence of its cardiac activity, 7 indicating ghrelin is a promising new therapeutic agent for cardiovascular diseases. In this review, we discuss some of the characteristic features of ghrelin treatment and its possible therapeutic roles in animals and patients afflicted with common cardiovascular diseases.