Plasma calcium as a surrogate measure for vitellogenin in fathead minnows (Pimephales promelas)

Numerous reports have demonstrated the vitellogenic response of fish exposed to estrogenic compounds in the aquatic environment. A strong correlation has been shown to exist between plasma vitellogenin and plasma calcium concentrations in salmonid fish. This study examines the relationship between plasma vitellogenin and calcium in a cyprinid fish, the fathead minnow (Pimephales promelus), which is a species commonly used to monitor water quality. Plasma vitellogenin was determined after exposure of male and female fish to proprietary pharmaceutical estrogens using an enzyme-linked immunosorbent assay (ELISA) developed specifically for fathead minnows. Plasma calcium was determined by flame atomic absorption spectroscopy (AA). This study demonstrated significant (P < 0.05) linear correlations between plasma vitellogenin and plasma calcium for males (r(2) = 0.70) females (r(2) = 0.83), and males and females combined (r(2) = 0.60), showing that plasma calcium could be an indirect measure of vitellogenin present in fathead minnows. Some of the limitations and advantages identified through these studies are discussed. (C) 2003 Elsevier Inc. All rights reserved.