Melamine is an important chemical raw material used in industries, which has potential health risks to animals and humans. Current research mainly focuses on the toxic effects of high-dose melamine ingestion. However, there are few reports on whether melamine at the current limited standard dose has adverse effects on various tissues and organs, and whether there are sensitive target genes for risk evaluation. For this, 24 female Kunming mice were fed 0, 1.8-, 3.6-, and 7.2- mg/kg/d melamine via drinking water for consecutive 28 days, respectively. The morphological changes of the ovarian, hepatic, and renal tissues were firstly observed. The results demonstrated that the histopathology of ovary, liver, and especially in kidney had been altered by melamine intake in female. And then, the transcriptional levels of MAPK signaling genes including p38, ERK1, ERK2, JNK1, and JNK2 in kidneys were investigated by real-time PCR. The data showed that ERK1 and p38 mRNAs expressions were up-regulated significantly by melamine, suggesting that ERK1 and p38 transcriptional levels in the kidney might to be considered as candidate targets for lower-dose melamine toxicity. This study not only provides potential targets for the diagnosis and prevention of melamine damage, but also helps to assess the health risks of the current minimum allowable levels of melamine in food and environment.

中文翻译：

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三聚氰胺诱导雌性小鼠肾脏主要器官组织病理学和 MAPK 信号基因转录水平的变化

三聚氰胺是工业中使用的重要化学原料，对动物和人类具有潜在的健康风险。目前的研究主要集中在高剂量三聚氰胺摄入的毒性作用上。但目前有限标准剂量的三聚氰胺是否对各种组织器官有不良影响，是否存在风险评估的敏感靶基因等方面的报道较少。为此，24 只雌性昆明小鼠分别连续 28 天通过饮用水分别喂食 0、1.8、3.6 和 7.2-mg/kg/d 三聚氰胺。首次观察卵巢、肝、肾组织的形态学变化。结果表明，雌性三聚氰胺摄入改变了卵巢、肝脏，尤其是肾脏的组织病理学。然后，MAPK 信号基因的转录水平包括通过实时PCR研究肾脏中的p38、ERK1、ERK2、JNK1和JNK2 。数据显示三聚氰胺显着上调ERK1和p38 mRNAs 的表达，表明肾脏中的ERK1和p38转录水平可能被认为是低剂量三聚氰胺毒性的候选靶标。该研究不仅为三聚氰胺损害的诊断和预防提供了潜在的目标，而且有助于评估当前食品和环境中三聚氰胺最低允许水平的健康风险。