| 摘要 |
Human pancreatic GRF(hpGRF), rat hypothalamic GRF(rGRF) and porcine hypothalamic GRF(pGRF) have been earlier characterized and synthesized. The invention provides synthetic peptides which are extremely potent in stimulating the release of pituitary GH in animals, including humans, which have resistance to enzymatic degradation in the body, and which contain the sequence: R1-R2-R3-Ala-Ile-Phe-Thr-R8-Ser-R10- Arg-R12-R13- Leu-R15- Gln-R17-R18- Ala-Arg-Lys-Leu- R23-R24-R25- Ile- R27- R28- Arg-Gln-Gln-Gly-Glu-R34-Asn-Gln-Glu-R38-R39-R40-Arg-R42-R43-R44 wherein R1 is a Tyr, D-Tyr, Met, Phe, D-Phe, pCl-Phe, Leu, His or D-His, which has either a C alpha Me or N alpha Me substitution or is unsubstituted; R2 is Ala or D-Ala; R3 is Asp or D-Asp; R8 is Ser, Asn, D-Ser or D-Asn; R10 is Tyr or D-Tyr; R12 is Arg or Lys; R13 is Ile or Val; R15 is Gly or D-Ala; R17 is Leu or D-Leu; R18 is Tyr or Ser; R23 is Leu or D-Leu; R24 is His or Gln; R25 is Glu, Asp, D-Glu or D-Asp; R27 is Met, D-Met, Ala, Nle, Ile, Leu, Nva or Val; R28 is Asn or Ser; R34 is Arg or Ser; R38 is Gln or Arg; R39 is Arg or Gly; R40 is Ser or Ala; R42 is Phe, Ala or Val; R43 is Asn or Arg; R44 is a natural amino acid; provided however that either (a) R1 has a C alpha Me or an N alpha Me substitution or (b) R17 and/or R23 is D-Leu or (c) R25 is either D-Glu or D-Asp and provided also that any or all of the residues between R29 and R44, inclusive, may be deleted; or a nontoxic salt thereof. The C-terminus is preferably amidated. These peptides as well as nontoxic salts thereof may be administered to animals, including humans and cold-blooded animals, to stimulate the release of GH and may be used diagnostically. |
