YIL781 hydrochloride is a potent and orally active ghrelin receptor (GHSR) antagonist. YIL781 hydrochloride produces a greater improvement in glucose homeostasis in rats. YIL781 hydrochloride inhibits the calcium response induced by ghrelin with pIC50 values of 7.90 and 8.27, respectively[2].In Vitro: YIL781 (10-300 nM) induces a concentration-dependent parallel rightward shift of the ghrelin CRC with a slight but statistically significant depression of the maximal response at 100 and 300 nM, reaching a similar agonist maximal response of approximately 90%.In Vivo: YIL781 (0.1 to 5 μg/5 μl) attenuates ghrelin-induced up-regulation of the blood glucose level. Thei.t. treatment with YIL781 alone does not affect the blood glucose level (F = 0.8160; P = 0.5095).