LRF Antagonists

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: R.sub.1 -R.sub.2 -R.sub.3 -Ser-Tyr-R.sub.4 -R.sub.5 -Arg-R.sub.6 wherein R.sub.1 is selected from the group consisting of dehydro Pro, dehydro D-Pro, Acetyl dehydro Pro and acetyl dehydro D-Pro; R.sub.2 is selected from the group consisting of D-Phe, Phe, N.alpha.Me-Phe, His, D-His, D-Trp, Trp and N.alpha.Me-Leu; R.sub.3 is selected from the group consisting of D-Trp, Trp D-Phe, Phe, Pro and D-His; R.sub.4 is selected from the group consisting of Gly, D-Trp, D-Phe, imBzl-D-His and D-Tyr; R.sub.5 is selected from the group consisting of Leu and N.alpha.Me-Leu; and R.sub.6 is selected from the group consisting of Pro-Gly-NH.sub.2 and Pro-NH-CH.sub.2 -CH.sub.3.

Dependencies are inferred from the claim text.