In this paper, compartmental pharmacokinetic models are built to predict the concentration of toxic phytochemical in the gastrointestinal tract and blood following oral intake by an individual vertebrate herbivore. The existing single and multiple dose pharmacokinetic models are extended by inclusion of impulsive differential equations which account for an excretion factor whereby unchanged toxins are excreted in the feces due to gastrointestinal mobility. An index α is defined to measure the fraction of bioavailability attributed to the excretion factor of gastrointestinal motility. Sensitivity analysis was conducted and suggests, for any toxin, the bioavailability index α depends mostly on absorption rate of toxin from gastrointestinal tract into the blood, frequency of elimination due to gastrointestinal motility, and the frequency of toxin intake, under the model assumptions.

中文翻译：

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多种剂量的药代动力学模型可预测脊椎动物食草动物中毒素的生物利用度。

在本文中，建立隔室药代动力学模型来预测个体脊椎动物食草动物口服摄入后胃肠道和血液中有毒植物化学物质的浓度。现有的单剂量和多剂量药代动力学模型通过包含脉冲微分方程进行扩展，该脉冲微分方程解释了一种排泄因子，从而由于胃肠道的活动性，粪便中排泄了不变的毒素。定义指数α以测量归因于胃肠动力的排泄因子的生物利用度的分数。进行了敏感性分析，并建议对于任何毒素，其生物利​​用度指数α 在模型假设下，主要取决于胃肠道对血液的毒素吸收率，胃肠道蠕动消除的频率以及毒素的摄入频率。