a Department of Genetics , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.
b Curriculum in Toxicology & Environmental Medicine, University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.
Inhal Toxicol. 2019 Feb;31(2):61-72. doi: 10.1080/08958378.2019.1597222. Epub 2019 Apr 25.
Complete systems for laboratory-based inhalation toxicology studies are typically not commercially available; therefore, inhalation toxicologists utilize custom-made exposure systems. Here we report on the design, construction, testing, operation and maintenance of a newly developed rodent ozone inhalation exposure system. Key design requirements for the system included large-capacity exposure chambers to facilitate studies with large sample sizes, automatic and precise control of chamber ozone concentrations, as well as automated data collection on airflow and environmental conditions. The exposure system contains two Hazelton H-1000 stainless steel and glass exposure chambers, each providing capacity for up to 180 mice or 96 rats. We developed an empirically tuned proportional-integral-derivative control loop that provides stable ozone concentrations throughout the exposure period (typically 3h), after a short ramp time (∼8 min), and across a tested concentration range of 0.2-2 ppm. Specific details on the combination of analog and digital input/output system for environmental data acquisition, control and safety systems are provided, and we outline the steps involved in maintenance and calibration of the system. We show that the exposure system produces consistent ozone exposures both within and across experiments, as evidenced by low coefficients of variation in chamber ozone concentration and consistent biological responses (airway inflammation) in mice, respectively. Thus, we have created a large and robust ozone exposure system, facilitating future studies on the health effects of ozone in rodents.
用于基于实验室的吸入毒理学研究的完整系统通常无法商业化获得；因此，吸入毒理学家使用定制的暴露系统。在这里，我们报告了一种新开发的啮齿动物臭氧吸入暴露系统的设计、构建、测试、操作和维护情况。该系统的关键设计要求包括大容量暴露室，以方便进行大样本量的研究；精确自动控制腔室臭氧浓度；以及对气流和环境条件的自动数据收集。该暴露系统包含两个哈泽尔顿 H-1000 不锈钢和玻璃暴露室，每个暴露室的容量最多可容纳 180 只小鼠或 96 只大鼠。我们开发了一个经验调整的比例积分微分控制回路，该回路可在整个暴露期（通常为 3 小时）内提供稳定的臭氧浓度，在短的斜坡时间（约 8 分钟）后，并在测试的 0.2-2ppm 浓度范围内提供稳定的臭氧浓度。提供了有关模拟和数字输入/输出系统组合的详细信息，用于环境数据采集、控制和安全系统，并且我们概述了系统维护和校准的步骤。我们表明，暴露系统在实验内部和之间都产生了一致的臭氧暴露，这表现在腔室臭氧浓度的低变异系数和小鼠气道炎症的一致生物学反应上。因此，我们创建了一个大型且强大的臭氧暴露系统，为未来在啮齿动物中研究臭氧对健康的影响提供了便利。
