Investigating Atrazine Accumulation and Histological Changes in the Hepatopancreas of Crayfish Post-Exposure

Yacoo, Kathrine E., Danielle N. Maxwell, Kaitlin S. Lambert, Ila Sayed, Victoria C. Torres, Daniel J. Dayfield, Kaldoun M. Barawi, Noor K. Abraham, Rachelle M. Belanger, Elizabeth S. Roberts-Kirchhoff, and Kendra R. Evans

Many pesticides are known to have long-term adverse effects on aquatic organisms, and thus it is of interest to explore the effects of pesticide accumulation in these species. We are investigating the accumulation of atrazine (ATR) in the hepatopancreas of the virile crayfish, Orconectes virilis. Crayfish were treated with environmentally-relevant ATR concentrations (80 and 300 ppb) and control concentrations (0 ppb (negative control) and 1000 ppb ATR (positive control)) for 15 days. Histological changes, including increased vacuolization, were visualized in the hepatopancreas following sectioning and staining with hematoxylin and eosin (H & E). It is of interest to correlate physiological changes with the level of accumulation of ATR, so we have developed and are evaluating a method to extract and quantitate the amount of ATR in the hepatopancreas. Hepatopancreas tissue was isolated from the crayfish, and ATR was extracted using a “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method. Following the extraction, the ATR was analyzed using liquid chromatography-mass spectrometry (LC-MS), which allows for the quantitation of ATR, its metabolites, and other pesticides that may accumulate in the tissue. A stable-isotope internal standard, ATR-d5, was included in the analysis and will be used to improve the accuracy and precision of the ATR quantitation.