VIP type peptides

Claim 1

A polypeptide of the general formula X--(Y').sub.n --Y.sub.15 Y.sub.16 Y.sub.17 Y.sub.18 Y.sub.19 Y.sub.20 --(Y").sub.m --Z in which X represents a hydrogen atom or an amine-protecting group, preferably a hydrogen atom; (Y') n represents a direct bond or Y.sub.11 Y.sub.12 Y.sub.13 Y.sub.14, Y.sub.12 Y.sub.13 Y.sub.14, Y.sub.13 Y.sub.14 or Y.sub.14 in which Y 11 represents Thr, Ser or the residue of another naturally occurring hydroxy amino acid, Y 12 represents Arg or the residue of another naturally occurring basic amino acid, Y 13 represents Leu, Phe or the residue of another naturally occurring hydrophobic amino acid, Y 14 represents Arg or the residue of another naturally occurring basic amino acid; Y 15 represents Lys or the residue of another naturally occurring basic amino acid, Y 16 represents Gln or the residue of another naturally occurring carboxamido amino acid, Y 17 represents Met or the residue of another naturally occurring neutral amino acid, Y 18 represents Ala or the residue of another naturally occurring hydrophobic amino acid, Y 19 represents Val or the residue of another naturally occurring hydrophobic amino acid, Y 20 represents Lys or the residue of another basic naturally occurring amino acid, (Y") m represents a direct bond or Y.sub.21, Y.sub.21 Y.sub.22 or Y.sub.21 Y.sub.22 Y.sub.23 in which Y 21 represents Lys or the residue of another basic naturally occurring amino acid, Y 22 represents Tyr or the residue of another naturally occurring hydrophobic amino acid, Y 23 represents Leu or the residue of another naturally occurring hydrophobic amino acid; and Z represents a hydroxyl group, or a group of the formula OR such COZ represents an ester, or a hydrazino group such that COZ represents a hydrazide, or NH 2 such that COZ represents an amide; and pharmaceutically acceptable salts thereof.