Abstract: The objective of the research was the achievement of antagonists of the luteinizing hormone releasing hormone (LHRH) which would have adequate antagonistic activity to prevent ovulation, and yet would not have a pronounced structural feature to release a histamine, in vivo. Some existing antagonists of LHRH produced edema of the face and extremities in rats. This recent recognition of the edematogenic and anaphylactoid activities of an antagonist of LHRH necessitated new structural changes if such antagonists were to be considered for potential use as contraceptive agents in the human. Consequently, 57 peptides have been designed, synthesized and bioassayed toward achieving a potent antagonist which releases negligible histamine.

Abstract: Disclosed are combinations of polypeptides acting in a synergistic manner to promote release and elevation of growth hormone levels in the blood of animals. Also disclosed are methods of promoting the release and elevation of growth hormone levels in the blood of animals using the disclosed combination of polypeptides.

Abstract: Disclosed are novel polypeptide compounds which promote the release and elevation of growth hormone levels in the blood of animals. Also disclosed are methods of promoting the release and elevation of growth hormone levels in the blood of animals using the disclosed polypeptide compounds.

Abstract: The chemical structure of the luteinizing hormone releasing hormone (LHRH) was elucidatd in 1971. Since then, a very large number of international investigators synthesized more than 100 monosubstituted and about 14 disubstituted analogs of LHRH. All of these analogs were synthesized from natural amino acids having the L-configuration. Not one of these approximately 114 analogs showed agonist activity equivalent to that of LHRH. Two of the 114 were about 60% as active, and neither one has had any utility. We have investigated the six individual L-amino acids which occur in positions 5, 7, and 8 of the four naturally occurring LHRH's which exist in porcine/ovine, salmon, and chicken tissue.

Abstract: Two sets of hormonal peptides are synthesized which are super agonists of the lutenizing hormone releasing hormone (LHRH). Chronic administration results in the inhibition of LHRH which is responsible for stimulating cell growth in the testes. One peptide has the D(dextro)-form of a mono-heterocyclic amino acid in position six (D-3-pyridyl-alanine) while the other peptide has a bi-heterocyclic amino acid in that same position (.beta.-(3-quinolyl)-D-.alpha.-alanine. Both peptides are less metabolically reactive than those in the prior art and yet both peptides are significantly more potent than LHRH itself.

Abstract: Two sets of hormonal peptides are synthesized which are super agonists of the luteinizing hormone releasing hormone (LHRH). Chronic administration results in the inhibition of LHRH which is responsible for stimulating cell growth in the testes. One peptide has the D(dextro)-form of a monoheterocyclic amino acid in position six (D-3-pyridyl-alanine) while the other peptide has a bi-heterocyclic amino acid in that same position (.beta.-(3-quinolyl)-D-.alpha.-alanine. Both peptides are less metabolically reactive than those in the prior art and yet both peptides are significantly more potent than LHRH itself.

Abstract: Pyridyl-alanyl decapeptides have been effectively synthesized and found to have antiovulatory activity. The exemplary [N-Ac-D-2-Nal.sup.1,pCl-D-Phe.sup.2, D-3-Pal.sup.3,D-Arg.sup.6,D-Ala.sup.10 ]-LHRH has very high potency to inhibit ovulation, both parenterally and orally. Also, this exemplary pyridyl-alanyl-decapeptide showed an unexpected prolonged duration of antiovulatory activity. Such pyridyl-alanyl-decapeptides are useful to control reproduction.

Abstract: Novel combinations comprising (a) at least one peptide having the following amino acid sequence ##STR1## wherein X.sub.1, X.sub.2, and X.sub.3 are selected from a group consisting of N-terminal and desamino alpha-carbon substitutions and a and b are 0 or 1, provided that a and b are always 0 when A.sub.1 is a desamino residue; A.sub.1 and A.sub.4 are selected from a group consisting of histidyl, arginyl, lysyl, .alpha.-naphthylalanyl, .beta.-naphthylalanyl, isoquinolyl, tyrosyl, tryptophyl, phenylalanyl, homologues and anlogues thereof, and, with respect to A.sub.1 only the desamino forms thereof; A.sub.2 and A.sub.5 are selected from a group consisting of D-histidyl, D-arginyl, D-lysyl, D-.alpha.-naphthylalanyl, D-.beta.-naphthylalanyl, D-isoquinolyl, D-tyrosyl, D-tryptophyl, D-phenyalanyl, homologues and analogues thereof; A.sub.