Kurtz David M, Glascoe Rallene, Caviness Gordon, Locklear Jacqueline, Whiteside Tanya, Ward Toni, Adsit Floyd, Lih Fred, Deterding Leesa J, Churchwell Mona I, Doerge Daniel R, Kissling Grace E
Quality Assurance Laboratory, Comparative Medicine Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
Food Safety and Inspection Service, USDA, Alameda, California, USA.
J Am Assoc Lab Anim Sci. 2018 Nov 1;57(6):703-711. doi: 10.30802/AALAS-JAALAS-18-000011. Epub 2018 Oct 25.
Sterilization of rodent feed by steam autoclaving is a common practice in many research institutions. Often we only consider the beneficial effects of this process-the reduction of microbial contamination-and forget that the high temperatures and pressures can have negative effects on diet quality. The purpose of our study was to assess both the physical and chemical changes to a standard rodent feed autoclaved at multiple sterilization temperatures and the effects of the treated diets on mice. Pelleted NIH31 rodent feed was autoclaved at 4 sterilization temperatures (230, 250, 260, and 270 °F). Feed pellet hardness and the acrylamide concentrations of the diets were tested and compared with irradiated NIH31 feed. Study diets were fed to mice for 28 d, after which tissue samples were collected for analysis of acrylamide, glycidamide (the active metabolite of acrylamide), and genotoxicity. Both feed pellet hardness and acrylamide concentration increased with increasing sterilization temperatures; however, neither affected feed intake or body weight gain. Plasma acrylamide and glycidamide were significantly elevated only in mice fed NIH31 diet autoclaved at 270 °F compared with the irradiated feed, whereas urine acrylamide and glycidamide metabolites were significantly elevated in most autoclaved diets. Liver DNA adducts, which correlate with genotoxicity, were significantly elevated in all autoclaved diets compared with the irradiated diet. Institutions that autoclave their animal diets should carefully consider the temperatures necessary to achieve feed sterilization and the type of studies in which these autoclaved diets are used.
在许多研究机构中，通过蒸汽高压灭菌法对啮齿动物饲料进行灭菌是一种常见的做法。我们常常只考虑这个过程的有益效果——减少微生物污染——而忘记了高温和高压可能会对饲料质量产生负面影响。我们研究的目的是评估在多个灭菌温度下进行高压灭菌的标准啮齿动物饲料的物理和化学变化，以及经处理的饲料对小鼠的影响。将颗粒状的NIH31啮齿动物饲料在4个灭菌温度（230、250、260和270°F）下进行高压灭菌。测试饲料颗粒硬度和饲料中的丙烯酰胺浓度，并与辐照过的NIH31饲料进行比较。将研究用饲料喂给小鼠28天，之后收集组织样本分析丙烯酰胺、环氧丙酰胺（丙烯酰胺的活性代谢物）和遗传毒性。饲料颗粒硬度和丙烯酰胺浓度均随灭菌温度的升高而增加；然而，两者均未影响采食量或体重增加。与辐照饲料相比，仅在喂食270°F高压灭菌的NIH31饲料的小鼠中，血浆丙烯酰胺和环氧丙酰胺显著升高，而在大多数高压灭菌饲料中，尿液丙烯酰胺和环氧丙酰胺代谢物显著升高。与遗传毒性相关的肝脏DNA加合物在所有高压灭菌饲料中均比辐照饲料显著升高。对动物饲料进行高压灭菌的机构应仔细考虑实现饲料灭菌所需的温度以及使用这些高压灭菌饲料的研究类型。
