Gontier-Latonnelle K, Cravedi J P, Laurentie M, Perdu E, Lamothe V, Le Menn F, Bennetau-Pelissero C
Unité Micronutriments, Reproduction, Santé (UMRS), ENITA de Bordeaux, 1, cours du Général de Gaulle 33175 Gradignan, France.
Gen Comp Endocrinol. 2007 Jan 15;150(2):298-308. doi: 10.1016/j.ygcen.2006.10.001. Epub 2006 Nov 13.
Genistein (G) is a xenoestrogen from soy present in fish diet. In vivo, a 50-fold difference in sensitivity to genistein on vitellogenin (VTG) synthesis was found when comparing trout and sturgeon. This difference was not linked to the estrogen receptor affinity nor to the sensitivity of induction of the VTG pathway. The study was performed to check if differences in the G disposition in the two species could explain their difference of sensitivity to G. A pharmacokinetic analysis of radiolabeled G was performed to determine its bioavailability and metabolism in both species. G was used at levels corresponding to fish farm exposure. G plasma levels after chronic ingestion were found to be 15.6 times higher in sturgeon than in trout. Sturgeon primarily produces sulfate conjugates after G ingestion whereas trout mainly produces glucuronides. Sturgeon was able to excrete orobol glucuronide in bile. An important first pass effect was suggested in both species. No accumulation of G or its metabolites was observed in the two species. Trout muscles accounted only for 0.14 of radioactivity 48 h post-ingestion similarly to sturgeon. Trout viscera accounted for 15% of the radioactivity 48 h post-ingestion. In sturgeon, 48 h post-ingestion, viscera accounted for 21.5% of the radioactivity. These rates decreased rapidly thereafter. The study partly explains the difference in sensitivity to G, previously recorded between the two species. In addition, it shows that human exposure to G through farmed fish consumption is negligible.
染料木黄酮（G）是鱼类饮食中存在的一种来自大豆的外源性雌激素。在体内，比较鳟鱼和鲟鱼时发现，它们对染料木黄酮诱导卵黄蛋白原（VTG）合成的敏感性相差50倍。这种差异既与雌激素受体亲和力无关，也与VTG途径诱导的敏感性无关。进行这项研究是为了检查这两个物种在G处置方面的差异是否可以解释它们对G敏感性的差异。对放射性标记的G进行了药代动力学分析，以确定其在两个物种中的生物利用度和代谢情况。G的使用水平与养鱼场的暴露水平相当。发现慢性摄入后鲟鱼的血浆G水平比鳟鱼高15.6倍。鲟鱼在摄入G后主要产生硫酸盐结合物，而鳟鱼主要产生葡萄糖醛酸结合物。鲟鱼能够在胆汁中排泄麦黄酮葡萄糖醛酸苷。两个物种都存在重要的首过效应。在这两个物种中均未观察到G或其代谢物的积累。摄入后48小时，鳟鱼肌肉中的放射性仅占0.14%，与鲟鱼相似。摄入后48小时，鳟鱼内脏中的放射性占15%。在鲟鱼中，摄入后48小时，内脏中的放射性占21.5%。此后这些比例迅速下降。该研究部分解释了先前记录的两个物种对G敏感性的差异。此外，它表明人类通过食用养殖鱼类接触G的量可以忽略不计。
