ANTIMYCIN - UPTAKE, DISTRIBUTION, AND ELIMINATION IN BROWN BULLHEADS (ICTALURUS-NEBULOSUS)

Raidoactive antimycin [a piscicide] was readily taken up in bile and tissues of I. nebulosus exposed to 0.045 .mu.g/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 .mu.g/g, after 12 h of exposure. The average amount of 14C-antimycin per fish was 0.94 .mu.g/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 14C-antimycin in the exposure solution decreased from 0.045 .mu.g/ml to 0.015 .mu.g/ml after 12 h and 0.010 .mu.g/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 .mu.g/ml of 14C-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 .mu.g/g to 0.05 .mu.g/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.