Uptake, tissue distribution, and metabolism of malachite green in the channel catfish (<i>Ictalurus punctatus</i>)

Abstract

The disposition of malachite green was determined in channel catfish (Ictalurus punctatus) after intravascular dosing (0.8 mg·kg n1 ) or waterborne exposure (0.8 mg·L n1 for 1 h). After intravascular dosing, mean plasma concentrations of the parent compound exhibited a triphasic decline with a terminal elimination half-life of 6.2 h. Malachite green was rapidly absorbed and concentrated in the tissues during waterborne exposure. The rate of accumulation was directly related to pH of the exposure water. After waterborne exposure, elimination of the parent compound from plasma also was triphasic with a terminal half-life of 4.7 h. In muscle, the half-life of the parent compound was approximately 67 h. Malachite green and its metabolites were widely distributed in all tissues. In fish exposed to 14 C-labeled malachite green, total drug equivalent