Comparison of sandwich enzyme-linked immunoadsorbent assay and radioimmunoassay for determination of exogenous glucagon-like peptide-1(7-36)amide in plasma.
A sensitive sandwich enzyme-linked immunoadsorbent assay (ELISA) for determination of exogenous glucagon-like peptide-1(7-36)amide (GLP-1(7-36)amide) in plasma samples from pharmacokinetic studies is described. The assay employs an N-terminally directed antibody and a C-terminally directed antibody. The ELISA has a working range from 10 to 500 pmol l-1, and can be applied to plasma samples from humans, dogs, pigs, minipigs, cats, rabbits, and rats. The assay was compared to a validated radioimmunoassay (RIA), employing an antibody directed against the mid-region of GLP-1. After s.c. administration of GLP-1(7-36)amide, the plasma immunoreactivity of GLP-1 (P-GLP-1-IR) measured by ELISA was markedly lower than P-GLP-1-IR measured by RIA. After HPLC fractionation of plasma samples with subsequent RIA and ELISA analyses of the fractions, this difference was shown to be due to cross reaction with biologically inactive fragments of GLP-1(7-36)amide in the RIA but not in the ELISA.
Pridal
L
L
Novo Nordisk A/S, Bagsvaerd, Denmark.
Ingwersen
S H
SH
Larsen
F S
FS
Holst
J J
JJ
Adelhorst
K
K
Kirk
O
O
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002415:Cats; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D006801:Humans; D008969:Molecular Sequence Data; D018377:Neurotransmitter Agents / Q000097:blood* / Q000276:immunology; D010446:Peptide Fragments / Q000097:blood* / Q000276:immunology; D011817:Rabbits; D011863:Radioimmunoassay; D051381:Rats; D012016:Reference Values; D012680:Sensitivity and Specificity; D017386:Sequence Homology, Amino Acid; D013552:Swine; D013556:Swine, Miniature
D000906:Antibodies; D000939:Epitopes; D018377:Neurotransmitter Agents; D010446:Peptide Fragments; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon