Ghrelin and cardiovascular diseases.

In 1999, a peptide from the stomach called ghrelin was discovered, which exerts potent growth hormone releasing powers. Subsequent studies revealed that it exerts a potent orexigenic action. In addition, the beneficial effects of ghrelin in cardiovascular diseases have been recently suggested. In humans as well as in animals, administration of ghrelin improves cardiac function and remodeling in chronic heart failure. In an animal model for myocardial infarction, ghrelin treatment early after coronary ligation effectively reduces fatal arrhythmia and, consequently, mortality, suggesting the potential therapeutic role of the peptide in acute myocardial infarction. Although how ghrelin may influence the cardiovascular system is not fully understood, the cardiovascular beneficial effects are mediated possibly through a combination of various actions, such as an increase in growth hormone level, an improvement in energy balance, direct actions to the cardiovascular cells, and regulation of the autonomic nervous activity. Of note, current experimental evidence suggests that ghrelin may act centrally to decrease sympathetic nervous system activity through peripheral afferent nerve. Thus, administration of ghrelin might become a unique new therapy for cardiovascular diseases.