Peptides which effect release of hormones

Claim 1

A peptide selected from those of the formulae: ##STR3## wherein R 1 is selected from the group consisting of Asn and desR 1 ; R 2 is selected from the group consisting of Trp and D-Trp; R 3 is selected from the group consisting of Phe and Thr; R 4 is selected from group consisting of Thr and desR 4 ; R 5 is selected from the group consisting of Ser, Phe and desR 5 , provided that at least one of R 1 , R 4 and R 5 is deleted; X is selected from the group consisting of H, and an alpha-amino protecting group; X 1 and X 6 are selected from the group consisting of H and a protecting group for Cys selected from S-p-methoxybenzyl, S-acetamidomethyl, S-trityl and S-benzyl; X 2 is selected from the group consisting of H and a side chain amino protecting group; X 3 , X 4 and X 5 are selected from the group consisting of H and a hydroxyl protecting group selected from the group consisting of acetyl, benzoyl, tert-butyl, trityl, benzyl and benzyloxycarbonyl; with the proviso that at least one of X, X 1 , X 2 , X 3 , X 4 , X 5 , and X 6 is other than hydrogen; .[.and.]. R 6 is selected from the group consisting of hydroxy, methoxy, and an anchoring bond used in solid phase synthesis linked to a solid resin support selected from the group consisting of --O--CH 2 -polystyrene resin support and O--CH 2 -benzylpolystyrene resin support.Iadd.; and Cys is either L-Cys or D-Cys.Iaddend..