Claudogenic-interceptive nonapeptides

DETAILED DESCRIPTION What is claimed is: 1.
The compound of the formula: L-p-Glu-L-His-L-Trp-L-Ser-L-Tyr-D-Trp-L-(N-methyl)Leu-L-Arg-L-Pro-NHC.
sub.
2 H.
sub.
5 or a non-toxic acid addition salt thereof.
2.
A method for terminating pregnancy in a female mammal which comprises administering a nonapeptide of the formula: L-p-Glu-L-His-L-Trp-Ser-L-Tyr-D-Trp-L-(N-methyl)Leu-L-Arg-L-Pro-NHC.
sub.
2 H.
sub.
5, or a pharmaceutically acceptable acid addition salt thereof, to said mammal, post coitally, in a daily regimen containing at least about 3 micrograms per kilogram host body weight for a time sufficient to terminate pregnancy.
3.
The method of claim 2 in which said nonapeptide is administered, orally or parenterally, to said mammal following a daily regimen beginning on day one after coitus and extending through about the first eight days post implantation.
4.
The method of claim 2 in which said nonapeptide is administered, orally or parenterally, following a daily regimen beginning on day one after coitus and extending through about day seven post coitus.




Description:
BACKGROUND OF THE INVENTION Many analogues of LRH have been recently produced and tested as agents for ovulation induction.
Modification of the amino acid sequence of LRH has been most advantageous to date with removal of the Gly.
sup.
10 group and production of the Pro-NHC.
sub.
2 H.
sub.
5 terminus, providing a compound reportedly three to five times as active as LRH itself.
Fujino et al.
, Biochem.
Biophys.
Res.
Commun.
49 863 (1972).
D-Ala.
sup.
6 -LRH was subsequently shown to be more potent than LRH, by Monahan et al.
, Biochemistry 12 4616 (1973).
Various other D-amino acids have been inserted in 6-position of LRH and des-Gly.
sup.
10 -Pro-NHC.
sub.
2 H.
sub.
5 -LRH to produce products with improved ovulation inducing properties.
U.
S.
3,913,412 and Vilchez-Martinez et al.
, Biochem.
Biophys.
Res.
Commun.
59 1226 (1974).
The potency of D-Ala.
sup.
6, des-Gly.
sup.
10 -LRH ethylamide was reported by Coy et al.
, Biochem.
Biophys.
Res