Law F C, Meng J
Department of Biological Sciences, Simon Fraser University, Burnaby, British Colombia, Canada.
Food Addit Contam. 1996 Feb-Mar;13(2):199-209. doi: 10.1080/02652039609374398.
A high level of 14C was found to bind irreversibly with the liver proteins of rainbow trout (Oncorhyncus mykiss) exposed to 135 mg/kg bodyweight of 14C-labelled furazolidone (14C-FZ) in fish feed daily for 10 days. After the cessation of 14C-FZ treatment, hepatic protein-bound 14C in trout stayed high for at least 30 days. The chemical identity of protein-bound 14C remained to be elucidated. However, a part of the protein-bound 14C in the liver and muscle could be released as 3-amino-2-oxazolidinone by acid hydrolysis. The formation of protein-bound 14C in the liver was investigated further with trout dosed intravenously with different 14C-FZ doses at 10 degrees C or with 5 mg/kg FZ at different water temperatures. 14C binding to the liver proteins was found to increase with increasing FZ dose or water temperature. Results of these studies indicate that protein-bound 14C in the muscle and liver of trout is related to the formation of reactive intermediates from FZ. However, additional studies on the identities of the protein-bound FZ residues are required before they can serve as useful biomarkers to monitor FZ exposure in farm fish.
研究发现，虹鳟（Oncorhyncus mykiss）每日摄食含135毫克/千克体重14C标记的呋喃唑酮（14C-FZ）的饲料，持续10天，其肝脏蛋白质会与高水平的14C发生不可逆结合。停止14C-FZ处理后，虹鳟肝脏中与蛋白质结合的14C至少30天内仍维持在高位。与蛋白质结合的14C的化学特性仍有待阐明。不过，肝脏和肌肉中与蛋白质结合的14C的一部分可通过酸水解以3-氨基-2-恶唑烷酮的形式释放出来。在10摄氏度下，给虹鳟静脉注射不同剂量的14C-FZ，或在不同水温下注射5毫克/千克的FZ，进一步研究肝脏中与蛋白质结合的14C的形成情况。结果发现，与肝脏蛋白质结合的14C会随着FZ剂量或水温的升高而增加。这些研究结果表明，虹鳟肌肉和肝脏中与蛋白质结合的14C与FZ形成的活性中间体有关。然而，在这些与蛋白质结合的FZ残留物能够作为监测养殖鱼类FZ暴露的有用生物标志物之前，还需要对其身份进行更多研究。
