Antimycin: Uptake, distribution, and elimination in brown bullheads (Ictalurus nebulosus)

Radioactive antimycin was readily taken up in bile and tissues of brown bullheads (Ictalurus nebulosus) exposed to 0.045 μg/ml of ¹⁴C-antimycin for as long as 48 h. Bile contained the most and blood the least radioactivity at all sampling periods. The highest concentration of ¹⁴C-antimycin in muscle was 0.12 μg/g, after 12 h of exposure. The average amount of ¹⁴C-antimycin per fish was 0.94 μg/g. The ¹⁴C-antimycin concentration decreased with the elapse of time in the muscle and in samples of combined head, skin, and viscera. The concentration of ^l4C-antimycin in the exposure solution decreased from 0.045 μg/ml to 0.015 μg/ml after 12 h and 0.010 μg/ml after 48 h. The initial half-life of ¹⁴C-antimycin in the exposure solution was about 6.5 h. A second group of fish was exposed to 0.045 μg/ml of ^l4C-antimycin for 48 h and then transferred to antimycin-free, flowing water for up to 96 h. The ¹⁴C-activity decreased in muscle tissue from 0.11 μg/g to 0.05 μg/g in 96 h. Half-life of ¹⁴C-antimycin was about 75 h in muscle and 61 h in the combined head, skin, and viscera.