Distribution of 14C-labelled Atrazine, Methoxychlor, Glyphosate, and Bisphenol-A in Goldfish Studied by Whole-Body Autoradiography (WBARG)

Abstract

Abstract Nonpersistent contaminants represent thousands of chemicals used as pesticides, pharmaceuticals, personal care products, additives, etc. Because of this diversity, the assessment of the environmental risks they may pose for the environment represents a formidable task. Identification of target organs is key information needed to orient further research on newlyinvestigated organic xenobiotics. We used whole-body autoradiography to visualize the distribution of 14C-labelled atrazine, methoxychlor, glyphosate, and bisphenol-A in goldfish (Carassius auratus) and identify target organs. Fish were exposed for 2 days (glyphosate and bisphenol-A) and 7 days (atrazine and methoxychlor) to the radiolabelled compounds at a concentration of 15 nM. They were then frozen, embedded in carboxymethylcellulose gel, 20-μm-thick cryosections were collected, freeze-dried, and exposed to phosphor screens to visualize the tissue distribution of radioactivity. Goldfish did not accumulate glyphosate. The three other compounds were accumulated, mostly in the gall bladder. Nevertheless, unforeseen accumulation sites were observed; atrazine accumulated in the uveal tract of the eye, high levels of radioactivity were found in the cerebrospinal fluid of goldfish exposed to methoxychlor, and an important accumulation of bisphenol-A was seen in urine, oral mucosa, esophagus, and intestinal lumen. The potential toxicological consequences of the accumulation of these chemicals at very specific locations within the fish body are discussed and further research suggested.