Newton Paul E, Bolte Henry F, Derelanko Michael J, Hardisty Jerry F, Rinehart William E
Huntingdon Life Sciences, Inc., East Millstone, New Jersey 08875-2360, USA.
Inhal Toxicol. 2002 Dec;14(12):1249-60. doi: 10.1080/08958370290084890.
Methylethylketoxime, also known as MEKO or 2-butanone oxime (CAS No. 96-29-7), is a clear, colorless to light yellow liquid at room temperature. It is an industrial antioxidant used as an antiskinning agent in alkyd paint, an industrial blocking agent for urethane polymers, and a corrosion inhibitor in industrial boilers, and can be found in some adhesives and silicone caulking products. Male CD-1 mice were exposed 6 h/day, 5 days/wk, for 1, 2, 4, or 13 wk via whole-body inhalation exposures to MEKO vapor concentrations of 0, 3 +/- 0.1, 10 +/- 0.3, 30 +/- 1, or 100 +/- 2 ppm (10 mice/group/interval). Satellite animals were removed after 1, 2, 4, or 13 wk of exposure and allowed to recover for 4 or 13 wk (5 mice/group/interval). After termination, the nasal turbinates were evaluated microscopically, and cross-sectional nasal maps of the lesions were prepared. At the end of the 1-, 2-, 4-, and 13-wk exposure periods, degeneration of the olfactory epithelium lining the dorsal meatus was seen in the anterior region of the nasal cavity. In a few instances, the olfactory epithelium covering the tips of the nasoturbinal scrolls projecting into the dorsal region of the nasal cavity was also degenerated. Large areas of olfactory epithelium lying laterally and posteriorly were unaffected. In general, approximately 10% or less of the total olfactory tissue was affected. In several instances, the degenerated olfactory epithelium was reepithelialized by squamous/squamoid and/or respiratory types of epithelium. Degeneration, which was dose related in incidence and severity, was seen in mice exposed to 30 and 100 ppm after 1 wk of exposure and in several mice exposed to 10 ppm after 13 wk of exposure. The incidence and severity of the degeneration present after 1 wk of exposure did not increase with the longer exposures. The olfactory degeneration was reversible. Recovery was complete within 4 wk following exposures at 10 ppm and nearly complete within 13 wk after exposures at 30 and 100 ppm. A no-observed-effect level (NOEL) for the olfactory degeneration was considered to be 3 ppm.
甲乙酮肟，也称为MEKO或2 - 丁酮肟（化学物质登记号：96 - 29 - 7），在室温下是一种清澈、无色至浅黄色的液体。它是一种工业抗氧化剂，用作醇酸漆中的防结皮剂、聚氨酯聚合物的工业封闭剂以及工业锅炉中的缓蚀剂，并且可在一些胶粘剂和有机硅填缝产品中找到。雄性CD - 1小鼠通过全身吸入暴露于浓度为0、3±0.1、10±0.3、30±1或100±2 ppm的甲乙酮肟蒸气中，每天暴露6小时，每周暴露5天，持续1、2、4或13周（每组/每个时间间隔10只小鼠）。在暴露1、2、4或13周后取出卫星动物，并使其恢复4或13周（每组/每个时间间隔5只小鼠）。处死动物后，对鼻甲进行显微镜评估，并绘制病变的鼻腔横断面图。在1、2、4和13周的暴露期结束时，在鼻腔前部可见覆盖背鼻道的嗅上皮发生变性。在少数情况下，覆盖伸入鼻腔背侧区域的鼻鼻甲卷轴尖端的嗅上皮也发生了变性。位于外侧和后侧的大片嗅上皮未受影响。一般来说，受影响的嗅组织总面积约为10%或更少。在一些情况下，变性的嗅上皮被鳞状/类鳞状和/或呼吸型上皮重新上皮化。变性在发生率和严重程度上与剂量相关，在暴露1周后暴露于30和100 ppm的小鼠以及暴露13周后暴露于10 ppm的几只小鼠中可见。暴露1周后出现的变性的发生率和严重程度并未随着暴露时间延长而增加。嗅上皮变性是可逆的。在暴露于10 ppm后4周内恢复完全，在暴露于30和100 ppm后13周内几乎完全恢复。嗅上皮变性的未观察到效应水平（NOEL）被认为是3 ppm。
