| 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 gondads. The peptides have the structure. X- beta -D-2NAL-R2-D-Trp-Ser-R5-R6-R7-Arg-Pro-R10 wherein X is hydrogen or an acyl group having 7 or less carbon atoms; R2 is Cl-D-Phe, F-D-Phe, NO2-D-Phe, Cl2-D-Phe or Br-D-Phe; R5 is Tyr or Cl-Phe; R6 is 4-NH2-D-Phe or D-Arg; R7 is Leu or N alpha Me-Leu; and R10 is Gly-NH2, NHCH2CH3 or D-Ala-NH2. |