Antide and related antagonists of luteinizing hormone release with long action and oral activity.
Antide is the decapeptide N-Ac-D-Nal(2),D-Phe(pCl),D-Pal(3),Ser,Lys(Nic),D-Lys(Nic),Leu,Lys(iPr),P ro,D- Ala-NH2 [Nal(2) represents 3-(2-naphthyl)alanine; Phe(p-Cl) represents 3-(4-chlorophenyl)alanine; Pal(3) represents 3-(3-pyridyl)alanine; Lys(Nic) represents N epsilon-nicotinoyllysine; Lys-(iPr) represents N epsilon-isopropyllysine], which is an antagonist of luteinizing hormone-releasing hormone (LHRH), which has high antiovulatory activity, releases negligible histamine, and is scheduled for scale-up, safety testing, and evaluation in the experimental primate and in clinical medicine. Thirty-five more peptides were synthesized, designed on antide with variations in positions 5-8. Of these, N-Ac-D-Nal(2),D-Phe(pCl),D-Pal(3),Ser,Lys(Pic),cis-D- Ala(PzAC),Leu,Lys(iPr),Pro,D-Ala-NH2 [Lys(Pic) represents N epsilon-picoloyllysine; Ala(PzAC) represents 3-(4-pyrazinylcarbonylaminocyclohexyl)alanine] was not only the most potent but also had higher antiovulatory activity than antide--i.e., 73% per 0.25 microgram and 100% per 0.5 microgram vs. 36% per 0.5 microgram and 100% per 1.0 microgram. Antide showed significant (P less than 0.001) duration of action when injected at a dose of 10 micrograms 44 hr before injection of 50 ng of the agonist [D-Qal(3)6]LHRH [Qal(3) represents 3-(3-quinolyl)alanine]. Antide showed oral antiovulatory activity at 600 micrograms (73%) and at 1200 micrograms (100%) with negligible difference between water and corn oil oral formulations.
Ljungqvist
A
A
Institute for Biomedical Research, University of Texas, Austin 78712.
Feng
D M
DM
Hook
W
W
Shen
Z X
ZX
Bowers
C
C
Folkers
K
K
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D006636:Histamine Release / Q000187:drug effects; D007986:Luteinizing Hormone / Q000097:blood; D009842:Oligopeptides / Q000494:pharmacology*; D010060:Ovulation / Q000187:drug effects; D051381:Rats
D000596:Amino Acids; D009842:Oligopeptides; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; C057022:iturelix