Ghrelin, an endogenous growth hormone secretagogue, is a novel orexigenic peptide that antagonizes leptin action through the activation of hypothalamic neuropeptide Y/Y1 receptor pathway. - Shintani,M.; Ogawa,Y.; Ebihara,K.; Aizawa-Abe,M.; Miyanaga,F.; Takaya,K. (Diabetes, 2001)