CYCLODIENE INDUCED BINDING PROTEIN

描述：(改编自《调查者摘要》)滋养彩虹 含低浓度环二烯杀虫剂的鲑鱼饲料 狄氏剂增加挑战剂量[14C]狄氏剂的胆汁排泄 300%-700%和[~3H]7，12-二甲基苯并[a]菲(DMBA)约300%。这 相互作用发生时没有细胞色素P-450诱导的证据 系统，UDP-葡萄糖醛酸基转移酶，或谷胱甘肽S-转移酶。精密度 从狄氏剂喂养的鲑鱼切下的肝脏切片累积大约两倍以上 [14C]来自介质的狄氏剂而不是来自对照鱼片的狄氏剂。肝脏切片来自 喂食狄氏剂的鲑鱼摄取量略有增加，但更明显 刺激[~3H]DMBA外流。初步免疫组织化学研究 没有提供诱导类多药耐药(MDR)的证据 狄氏剂投喂虹鲑鱼肝脏中的蛋白质。柱层析 表明狄氏剂增加了[~3H]DMBA和[~3H]苯并[a]芘的结合 虹鱼肝细胞浆中的蛋白质(S)。的工作假说 建议的研究是狄氏剂诱导肝脏结合蛋白(S) 亲脂性阴离子代谢物在胆汁排泄中的重要作用 外源生物。虹鲑鱼正在成为研究的有用模型 化学致癌和作为哨兵物种在评估地位和 水污染的程度。鉴定一个结合蛋白，该结合蛋白可能是 某些亲脂性外源化合物在肝脏消除时的速度限制将 彩虹鲑鱼中它们的性情的高级机械解释 模特。这项提议的目标是：(1)提纯 虹鱼胞质中狄氏剂诱导的DMBA结合蛋白； 与该蛋白质进行竞争性结合分析；以及(3)确定 该蛋白质的N-端序列由20-30个氨基酸组成。

DESCRIPTION: (Adapted from the Investigator's Abstract) Feeding rainbow trout diet containing low concentrations of the cyclodiene insecticide dieldrin increases biliary excretion of a challenge dose of [14C]dieldrin 300-700% and [3H]7,12-dimethylbenz[a]anthracene (DMBA) about 300%. This interaction occurs without evidence of induction of the cytochrome P-450 system, UDP-glucuronyltransferase, or glutathione S-transferases. Precision cut liver slices from dieldrin-fed trout accumulate about two-fold more [14C] dieldrin from medium than slices from control fish. Liver slices from dieldrin fed trout exhibit slightly increased uptake but more markedly stimulated efflux of [3H]DMBA. Preliminary immunohistochemical studies provide no evidence for induction of a multidrug resistance (mdr)-like protein in liver of dieldrin fed rainbow trout. Column chromatography indicates dieldrin increases [3H]DMBA and [3H]benzo[a]pyrene binding protein(s) in rainbow trout hepatic cytosol. The working hypothesis for the proposed research is that dieldrin induces hepatic binding protein(s) important in biliary excretion of anionic metabolites of lipophilic xenobiotics. The rainbow trout is emerging as useful model in research on chemical carcinogenesis and as a sentinel species in assessing status and extent of water contamination. Identifying a binding protein which may be rate limiting in hepatic elimination of some lipophilic xenobiotics would advance mechanistic explanations of their disposition in the rainbow trout model. The objectives for this proposal are to: (1) purify a dieldrin-inducible DMBA binding protein from rainbow trout cytosol; (2) conduct competitive binding assays with this protein; and (3) determine the N-terminal sequence of 20-30 amino acids for this protein.