Comparison of extraction methods and assay validation for salmon insulin-like growth factor-I using commercially available components.

摘要: Insulin-like growth factor-binding proteins (IGFBPs) may interfere with accurate measurement of plasma IGFs in radioimmunoassay (RIA). Although several simplified extraction methods for have been developed, these are not always validated differing physiological states, developmental stages, and animal species. For teleost fish, neither the necessity nor validity IGF RIA is widely established. We systematically examined acid-ethanol (AE) extraction, AE followed by cryoprecipitation (AEC extraction), SP-Sephadex salmon IGF-I using commercially available components (GroPep Pty Ltd). Displacement curves extracted AE, AEC, were parallel to those standard. Measured levels from stages under different experimental conditions significantly increased extractions comparable after acid-size exclusion chromatography (SEC). On Western ligand blotting digoxigenin-labeled human IGF-I, intensity IGFBP bands remaining reduced although some IGFBPs remained. However, residual did measurably based on quantitative comparison acid-SEC. conclude that this necessary since measured values routinely lower unextracted samples, applicable components. Using nonmaturing precociously maturing chinook spring extraction. During spring, fish fed grew well, level was correlated body weight both fish. This result indicates circulating plays a key role controlling as