Presence of anti-insulin natural autoantibodies in healthy cats and its interference with immunoassay for serum insulin concentrations |
| |
| Authors: | N Nishii M Takasu M Kojima T Hachisu K Wakabayashi A Iwasawa S Maeda Y Ohba H Kitagawa |
| |
| Institution: | 1. Laboratory of Veterinary Pharmacotherapeutics, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan;2. Laboratory of Veterinary Clinical Theriogenology, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan;3. Laboratory of Comparative Biochemistry, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan;4. Laboratory of Veterinary Internal Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan;5. Shibayagi Co., Ltd., Gunma 377-0007, Japan |
| |
| Abstract: | A substance interfering with the enzyme-linked immunosorbent assay (ELISA) for feline insulin concentration was investigated in healthy cats. An insulin-binding substance isolated from feline serum showed 2 bands at 25 and 50 kDa in SDS-PAGE, suggesting the presence of immunoglobulin G (IgG). Insulin-binding IgG from healthy cats indeed reduced insulin immunoreactivity in the ELISA for determining insulin concentration. The insulin-binding IgG was polyclonal/polyreactive and showed certain specificity, high affinity, and high binding capacity, which was evaluated by liquid-phase radioimmunoassay with Scatchard plot analysis. Epitope analysis revealed that the insulin-binding IgG showed significant binding at residues A1-5 and B20-30 of the insulin molecule. Removal of the antibodies from serum enabled the determination of serum insulin concentrations by ELISA. Our data indicated that serum from healthy cats contained substantial amounts of natural autoantibodies combined with insulin, and that the antibodies interfered with the heterologous immunoassay for serum insulin concentration. |
| |
| Keywords: | NAAb natural autoantibody DCC dextran-coated charcoal |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
