Validation in rat plasma of a direct radioimmunoassay for a luteinizing hormone-releasing hormone antagonist (BIM 21009)
Rabbits were immunized with [Ac-D-beta-Nal1-, D-p-Cl-Phe2, D-Phe3, D-Arg6, Phe7, D-Ala10]LHRH (BIM 21009) coupled to bovine serum albumin using bis-diazotized benzidine. The best antiserum had an affinity of 5. 10(-10) M and a specificity directed against the C-terminal part of the molecule. The antiserum was not affected by native LHRH but reacted to some extent with detergents. Assay of free-peptide plasma after gel filtration on Ultrogel AcA 34 showed apparent immunoreactivity associated with albumin and lipoproteins. The sensitivity of direct assay was 0.4 ng/ml. Measurements of BIM 21009 after s.c. injection in rats showed the resistance of the peptide to elimination. The specificity of the determinations in plasma were checked by High Performance Liquid Chromatography.
Ezan
E
E
Institut Pasteur, Unité de Radioimmunologie Analytique, Paris, France.
Drieu
K
K
Moreau
J P
JP
Dray
F
F
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000097:blood; D008969:Molecular Sequence Data; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
C055689:BIM 21009; D007987:Gonadotropin-Releasing Hormone