Development of a time-resolved fluoroimmunoassay for salmon insulin-like growth factor binding protein-1b
Autor: | E.M. Hevrøy, Miki Fukuda, Munetaka Shimizu, Kohei Kawaguchi, Nobuto Kaneko, Akihiko Hara |
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Rok vydání: | 2015 |
Předmět: |
medicine.medical_specialty
Time Factors Physiology medicine.medical_treatment Blotting Western Smoltification Fluorescent Antibody Technique Growth Body weight Biochemistry Insulin-like growth factor-binding protein Insulin-like growth factor binding protein Basal (phylogenetics) Salmon Internal medicine medicine Animals Molecular Biology Antiserum Immunoassay biology medicine.diagnostic_test Catabolism Growth factor Fasting Insulin-Like Growth Factor Binding Protein 1 Endocrinology biology.protein hormones hormone substitutes and hormone antagonists |
Zdroj: | Comparative biochemistry and physiology. Part A, Molecularintegrative physiology. 187 |
ISSN: | 1531-4332 |
Popis: | In salmon plasma/serum, three major insulin-like growth factor binding proteins (IGFBPs) are consistently detected at 22-, 28- and 41-kDa. The 22-kDa form has been identified as IGFBP-1b and shown to increase under catabolic conditions. We developed a competitive time-resolved fluoroimmunoassay (TR-FIA) for salmon IGFBP-1b. Purified salmon IGFBP-1b was used for biotin-labeling, assay standard and antiserum production. The TR-FIA did not cross-react with the 41-kDa form (IGFBP-2b) but showed 3% cross-reactivity with the 28-kDa form (IGFBP-1a). It measured IGFBP-1b levels as low as 0.4 ng/ml, and ED80 and ED20 were 0.9 and 24.6 ng/ml, respectively. There appears to be little interference by IGF-I. Using the TR-FIA, serum IGFBP-1b levels were measured in individually-tagged underyearling masu salmon fed or fasted for 5 weeks, or fasted for 3 weeks followed by refeeding for 2 weeks. Fasting for 3 weeks significantly increased circulating IGFBP-1b levels, while it returned to the basal levels after prolonged fasting for additional 2 weeks. Serum IGFBP-1b level negatively correlated with body weight, condition factor, specific growth rate and serum IGF-I level. During parr-smolt transformation of masu salmon, average circulating IGFBP-1b levels were the highest in May. There was a positive correlation between serum IGFBP-1b and IGF-I, which is in contrast to that in the fasting/feeding experiment. IGFBP-1b also showed a positive relationship with gill Na+, K+-ATPase activity. These results suggest that the relationship between circulating IGFBP-1b and IGF-I during smoltification differs from that during fasting and IGFBP-1b may play a role in the development of hypoosmoregulatory ability. (C) 2015 Elsevier Inc. All rights reserved. |
Databáze: | OpenAIRE |
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