Cook J C, Kaplan M A, Davis L G, O'Connor J C
DuPont-Haskell Laboratory for Toxicology and Industrial Medicine, Newark, Delaware 19714, USA.
Regul Toxicol Pharmacol. 1997 Aug;26(1 Pt 1):60-8. doi: 10.1006/rtph.1997.1120.
One of the components of our research program is development of a mode-of-action screening battery to detect several different types of endocrine-active compounds (EACs). Our working hypothesis is that a comprehensive short-term in vivo/in vitro battery can be developed to identify endocrine toxicants using a collection of endpoints. The goals of this battery are that it be quick, cost effective, and predictive. The purpose of this battery is to identify potential EACs and to assess their potency in order to prioritize compounds for further study. Two in vivo screens (intact male and ovariectomized female rats) are being evaluated for their ability to detect several different types of endocrine activity. To validate this screen, 15 compounds with known endocrine activities are being used to evaluate a collection of different endpoints for their variability, stability over time, predictiveness, and dose dependency. These positive controls were chosen because they can modulate development, reproduction, or cancer. The advantage of an in vivo screen is that it utilizes a metabolically and physiologically intact system. The male in vivo battery will be used to assess several different types of endocrine activity, primarily by using a comprehensive hormonal battery. The female in vivo battery will be used to identify compounds which are either estrogenic/antiestrogenic or can alter the prolactin pathway. The in vitro portion of the screening battery consists of a yeast transactivation system (YTS). The YTS is being evaluated for its ability to identify compounds which are agonists or antagonists to the estrogen, androgen, or progesterone receptors. The expression of mammalian receptors in yeast allows for assessment of steroid-dependent transcriptional activators. The value of this system is that it can be used as a routine screen for compounds that interact with steroid receptors. Alterations in ligand binding to these receptors can be correlated with alterations in development via masculinization of females and/or feminization of males, decreases in reproductive success, or modulation of cancer incidence from in vivo tests. The in vivo and in vitro screens are designed to be run in parallel with built-in redundancy in order to reduce the probability of false-negative/ positive responses.
我们研究项目的组成部分之一是开发一种作用模式筛选组套，以检测几种不同类型的内分泌活性化合物（EAC）。我们的工作假设是，可以开发一种全面的短期体内/体外组套，利用一系列终点指标来识别内分泌毒物。该组套的目标是快速、经济高效且具有预测性。此组套的目的是识别潜在的EAC，并评估其效力，以便对化合物进行优先级排序以供进一步研究。正在评估两种体内筛选方法（完整雄性大鼠和去卵巢雌性大鼠）检测几种不同类型内分泌活性的能力。为了验证此筛选方法，正在使用15种具有已知内分泌活性的化合物来评估一系列不同终点指标的变异性、随时间的稳定性、预测性和剂量依赖性。选择这些阳性对照是因为它们可以调节发育、生殖或癌症。体内筛选的优势在于它利用了代谢和生理功能完整的系统。雄性体内组套将主要通过使用全面的激素组套来评估几种不同类型的内分泌活性。雌性体内组套将用于识别具有雌激素/抗雌激素活性或可改变催乳素途径的化合物。筛选组套的体外部分包括酵母反式激活系统（YTS）。正在评估YTS识别作为雌激素、雄激素或孕激素受体激动剂或拮抗剂的化合物的能力。酵母中哺乳动物受体的表达允许评估类固醇依赖性转录激活因子。该系统的价值在于它可作为与类固醇受体相互作用的化合物的常规筛选方法。配体与这些受体结合的改变可通过雌性雄性化和/或雄性雌性化与发育改变、生殖成功率降低或体内试验中癌症发病率的调节相关联。体内和体外筛选设计为并行运行且具有内置冗余，以降低假阴性/阳性反应的概率。
