Toxicokinetics of atrazine in embryos of the zebrafish (Danio rerio)

Atrazine (2-chloro-4-ethylamino-6-isopropglamine-s-triazine) a widely used selective herbicide, Due to its persistence, it is present in many surface waters, contaminating nontarget organisms such as fish, Teratogeny of atraz ine was examined during the first 48 h of zebrafish development (embryo tes t) and correlated to effects on the microsomal and soluble glutathione S-tr ansferases (m-/sGST; EC 2.5.1.18), Atrazine at 4 mg/L disturbed the normal development to long pec stage, at concentrations between 10 and 20mg/L it c aused retardations in organogenesis, a slowdown of movements, and functiona l disturbances of heart and circulatory system, m- and sGST activities were affected by atrazine in all investigated developmental stages, Atrazine el evated the mGST activity dose dependently up to a concentration of 5 mg/L, and the sGST up to 1 mg/L, Higher atrazine concentrations caused a decrease of GST activity, especially of the sGST of the younger stages, 32 cells an d 75% epiboly. This might indicate that the detoxication system itself is a ffected, which then gives rise to morphological abnormalities during fish d evelopment. In vitro tests were performed to purify and characterize GST-fo rmed atrazine metabolites by the use of ESI-HPLC-MS, mGST showed higher con version rates compared to sGST. (C) 2001 Academic Press.