Ghrelin: more than endogenous growth hormone secretagogue

Since its discovery 10 years ago, intensive research has been performed on ghrelin. The significance of ghrelin as a growth hormone releasing hormone, appetite regulator, energy conservator, and sympathetic nerve suppressor has now been well established. In this review, we summarize recent topics on ghrelin, such as the processing protease of the ghrelin precursor, ghrelin O-acyl transaferase, ghrelin knockout and transgenic mice, and the molecular mechanism of ghrelin's orexigenesis.