Evaluation of a commercial kit for measuring vitellogenin in the fathead minnow ( Pimephales promelas)

Abstract

Vitellogenin (vtg) concentrations in oviparous animals such as fish represent an integrated indicator of the status of the reproductive endocrine system. As such, vtg is a common measurement endpoint in tests designed to detect certain classes of endocrine-disrupting chemicals (EDCs). The most common approach to measuring vtg is via enzyme-linked immunosorbent assays (ELISAs). However, because labs testing EDCs in fish often use slightly different ELISAs (e.g., in terms of antibodies, binding antigens, standards), results among studies are not always comparable. One approach to obviating this would be for researchers to use standardized ELISA kits from a common source(s). The fathead minnow ( Pimephales promelas) is a small fish model commonly used for EDC testing. The purpose of this study was to evaluate a recently developed commercial ELISA kit for measuring vtg in the fathead minnow. The commercial ELISA, based on a monoclonal antibody to fathead minnow vtg, was compared to an ELISA that utilizes a fathead minnow polyclonal antibody, which has been used extensively in our lab and others for several years. Plasma samples for this comparison came from three studies in which fathead minnows had been exposed to different model EDCs, including an androgen (17 β-trenbolone), an anti-androgen (flutamide), and two CYP19 (aromatase) inhibitors (prochloraz, fadrozole). Results obtained using the two different ELISA methods were consistently similar.