Distribution of 14C-atrazine following an acute lactational exposure in the Wistar rat

The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg C-14-atrazine (C-14-ATR) by gavage. C-14-ATR was administered to the nursing dam on postnatal day 3 by oral gavage. Two and a half hours after exposure of the mother to C-14-ATR, the pups were allowed to nurse for 30 min. At the end of the nursing period, radiolabelled residues of C-14-ATR [or C-14-chlorotriazines (C-14-CITRI)] were measured in the organs and tissues of the perfused dam and in the stomachs and brains of the rat pups. Both the 2 and the 4 mg atrazine treatments resulted in a transfer of approximately 0.007% of C-14-CITRI to the stomach (indicator of milk content) and 0.0002% to the brains of the offspring following the 30-min nursing period. Three hours following the dose of C-14-ATR, there was a distribution of C-14-CITRI to the organs of the dam, with the highest amounts in the liver and kidney (1.1 and 0.3% of the administered dose, respectively). Approximately 0.003% of the administered dose was present in three different brain sections of the dam following both doses of C-14-ATR. The results of this study demonstrate that C-14-CITRI are present in small concentrations in the brain and tissues of the dam (adult female) and provide evidence that atrazine or the metabolites can have direct effects on neuroendrocrine function. The results also provide information for postnatal distribution into the suckling neonate during early lactation. (c) 2007 Published by Elsevier Inc.