A peptide compound having the formula (I): ** Formula ** X10 represents an amino acid residue selected from Tyr, Leu, Val, Ile, Phe, phenylglycine, 1-naphthylalanine, 2-fluorophenylalanine, cyclohexylglycine and tert-leucine, X14 represents an amino acid residue selected from Leu and Nle X21 represents an amino acid residue selected from Asp and Glu, X29 represents an amino acid residue selected from Gly and Thr, R1 represents OH or NH2 or a salt or solvate thereof.Un compuesto peptídico que tiene la fórmula (I):**Fórmula** X10 representa un residuo aminoacídico seleccionado de Tyr, Leu, Val, Ile, Phe, fenilglicina, 1-naftilalanina, 2- fluorofenilalanina, ciclohexilglicina y terc-leucina, X14 representa un residuo aminoacídico seleccionado de Leu y Nle X21 representa un residuo aminoacídico seleccionado de Asp y Glu, X29 representa un residuo aminoacídico seleccionado de Gly y Thr, R1 representa OH o NH2 o una sal o solvato de este.
