The GHSR 1a antagonist that we used, D-Lys-3-GHRP-6 [His-D-Trp-D-Lys-Trp-D-Phe-Lys-NH2], has been used primarily to investigate the role of ghrelin in food intake studies. D-Lys3-GHRP-6 is a selective and potent inhibitor of GHSR 1a (Pinilla et al., 2003; Sethumadhavan et al., 1991) with an IC50 of 0.9 µM (Traebert et al., 2002; Tocris Bioscience literature).
