Abstract: Improved CRF peptide antagonists have the formula: ##STR1## wherein R.sub.20 is Cys or Glu; R.sub.23 is Cys, Lys or Orn; provided that when R.sub.20 is Cys, R.sub.23 is Cys and when R.sub.20 is Glu, R.sub.23 is Lys or Orn; or a nontoxic addition salt thereof. Specific CRF antagonists disclosed include (cyclo 20-23) [D-Phe.sup.12, Lys.sup.23, Nle.sup.21,38, ]rCRF(12-41); (cyclo 20-23) [D-Phe.sup.12, Orn.sup.23, Nle.sup.21,38 ]rCRF(12-41) and (cyclo 20-23) [D-Phe.sup.12, Cys.sup.20, Cys.sup.23, Nle.sup.21,38 ]rCRF(12-41).

Abstract: Agonists and antagonists of rCRF are disclosed that exhibit good binding affinity to CRF receptors. One exemplary agonist is: H-Ser-Gln-Glu-Pro-Pro-Ile-Ser- Leu-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg-Glu-Met-Leu-Glu-Met- Ala-Arg-Ala-Glu-Gln-Glu-Ala-Glu-Gln-Ala-Ala-Leu-Asn-Arg- Leu-Leu-Leu-Glu-Glu-Ala-NH.sub.2. In the agonists, one or more of the first five N-terminal residues may be deleted or may be substituted by a peptide up to 10 amino acids long. A number of other substitutions may also be made throughout the chain. Similar peptides which function as CRF antagonists are created by deleting the first 7, 8 or 9 N-terminal residues. These analogs are coupled to a cytotoxin, such as gelonin, by a dialdehyde or the like, e.g., glutaraldehyde. The conjugates may be used to eliminate CRF Target Cells, and thus to regulate secretion of ACTH, .beta.-lipotropin and the like.

Abstract: Analogs of CRF are disclosed that can be administered to achieve a substantial elevation of ACTH, .beta.-endorphin, .beta.-lipotropin, other products of the pro-opiomelanocortin gene and corticosterone levels and/or a lowering of blood pressure over an extended period of time. One analog which has been found to be particularly preferred is: [His.sup.20, Nle.sup.21, Leu.sup.38 ]-rCRF. In the analogs, one or more of the first five N-terminals residues may be deleted or may be substituted by a peptide up to 10 amino acids long and/or by an acylating agent containing up to 7 carbon atoms. A number of other substitutions may also be made throughout the chain. These analogs or pharmaceutically or veterinarily acceptable salts thereof, dispersed in a pharmaceutically or veterinarily acceptable liquid or solid carrier, can be administered to mammels, including humans. These analogs may also be used as stimulants to elevate mood and improve memory and learning.

Abstract: Several known members of the corticotropin releasing factor (CRF) family have been synthesized and tested, including human and rat CRF which have the formula: H-Ser-Glu-Glu-Pro-Pro-Ile-Ser-Leu-Asp-Leu-Thr-Phe-His- Leu-Leu-Arg-Glu-Val-Leu-Glu-Met-Ala-Arg-Ala-Glu-Gln- Leu-Ala-Gln-Gln-Ala-His-Ser-Asn-Arg-Lys-Leu-Met-Glu- Ile-Ile-NH.sub.2. Peptides are herein disclosed that are potent competitive antagonists of CRF in mammals. One which has been found to be particularly potent is: H-D-Phe-His-Leu-Leu-Arg-Glu-Val-Leu-Glu-Nle-Ala- Arg-Ala-Glu-Gln-Leu-Ala-Gln-Gln-Ala-His-Ser-Asn- Arg-Lys-Leu-Nle-Glu-Ile-Ile-NH.sub.2. One that has shown particularly prolonged duration of potency is: H-D-Phe-His-Leu-Leu-Arg-Glu-Val-Leu-Glu-Nle-Ala- Arg-Ala-Glu-Gln-Leu-Ala-Gln-Gln-Ala-His-Ser-Asn- Arg-Lys-CML-Nle-Glu-Ile-Ile-NH.sub.2.