6533b859fe1ef96bd12b7679

RESEARCH PRODUCT

Kinetics and metabolism of 14C-lindane and 14C-atrazine in early life stages of zebrafish (Brachydanio Rerio)

subject

description

Abstract Fertilized eggs, yolk sac larvae, and juveniles of zebrafish were exposed to 14C-lindane and 14C-atrazine under static conditions and the uptake was studied for a period of 48 hours. After 24 hours, a number of animals were transferred into pesticide-free running water and the elimination was examined for another 24 hours. The bioconcentration factors (BCFs) as well as the rate constants for uptake and elimination were calculated. Except for the lindane uptake by eggs and the atrazine uptake by juveniles, the steady state was reached within five hours. For all tested developmental stages the bioconcentration factor of lindane distinctly exceeded 100, whereas it was less than 10 in case of atrazine. More than 90 % of the lindane content at steady state was eliminated within 24 hours, but only 70 to 85 % of the incorporated atrazine. However, comparable amounts remained when related to body weight: approximately 2.3 μmol atrazine/kg and 3.4 μmol lindane/kg. Juvenile zebrafish metabolized 50 % of the lindane and 4 % of the atrazine within 40 hours. Two groups of metabolites were seperated from the exposure medium: the ether- and the non-ether-extractable compounds. The metabolites were isolated by HPLC. 9 and 3 metabolites were detected for lindane, and 1 and 3 metabolites were detected for atrazine in the ether-soluble fraction and the water-soluble fraction, respectively.