Meeting Abstract

P3.192  Tuesday, Jan. 6  A technique for measuring multiple hormones from individual water samples using commercial enzyme immunoassays KIDD, C.E.; KIDD, M.R.; HOFMANN, H.A.*; Univ. of Texas at Austin; Univ. of Texas at Austin; Univ. of Texas at Austin ckidd@mail.utexas.edu

Understanding the relationship between hormones and behavior requires the concurrent examination of multiple hormones. However, repeated blood sampling can impact the very behavior under study and compromise the subjects overall condition, particularly in small animals. Also, hormones released into the water by teleost fishes can play a role in schooling, migration, alarm reactions, behavioral and physiological responses during reproduction, and parent-offspring interactions. Consequently, the non-invasive analysis of hormone levels in fish holding water using either radioimmunoassay or enzyme immunoassay (EIA) is becoming increasingly common, yet few studies measure more than one hormone at a time. Commercial EIAs for different hormones often rely on different assay buffers, which can make measuring multiple hormones from the same water sample difficult, if not impossible. Using the African cichlid fish Astatotilapia burtoni , a major model system for the analysis of the molecular, endocrine and neural mechanisms underlying socially regulated plasticity in brain and behavior, we first introduce a procedure that allows the measurement of 17beta-estradiol (E2), testosterone (T), progesterone (P), and prostaglandin F2 alpha (PGF) from a single concentrated water sample using commercial EIAs. We validate this approach by correlating waterborne levels of these hormones with the circulating levels obtained from plasma samples of the same animals. Waterborne hormone levels correlate strongly with plasma values for E2 (r=0.87), T (r=0.61), P (r=0.801) and PGF (r=0.736). This technique can be applied in any aquatic species and will serve as a powerful tool for elucidating the hormonal regulation of behavior.