| abstract |
Peptides which inhibit the secretion of gonadotropins by the pituitary gland and inhibit the release of steroids by the gonads. Administration of an effective amount prevents ovulation of female mammalian eggs and/or the release of steroids by the gonads. The peptides have the structure: R1-dehydro Pro-R2-D-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 wherein R1 is selected from the group consisting of hydrogen, formyl, acetyl, acrylyl, benzoyl and allyl; R2 is selected from the group consisting dichloro-D-Phe, C alpha Me4Cl-D-Phe, (CH3)5-D-Phe, CF3-D-Phe, F-D-Phe, difluoro-D-Phe, AcNH-D-Phe, NO2-D-Phe, dinitro-D-Phe, Br-D-Phe, dibromo-D-Phe, CH3S-D-Phe, OCH3-D-Phe and CH3-D-Phe, wherein any D-isomer amino acid can be substituted for D-Trp in the 6-position, and wherein N alpha MeLeu may be substituted for Leu. |