APPLICATION OF TRANSGENIC MICE TO THE TOXICOLOGICAL TESTING

转基因小鼠在毒理学检测中的应用

• 批准号: 09557208
• 负责人: NAKAYAMA Kazuo
• 金额: $ 3.46万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09557208/
• 关键词: Mutagenicity testing; HITEC mouse; Cytochrome P450; CYP3A7; Fetus-specific; Metabolic activation; Aflatoxin B1; DNA damage

We have six lines of transgenic mice carrying human CYP3A7 cDNA.In M10 mouse, CYP3A7 is expressed in the small intestine but not in the kidney, while M2 mouse expresses CYP3A7 in the kidney. HITEC mouse is a transgenic mouse developed to detect mutagenic potency of various chemicals in vivo. The CYP3A7/HITEC mice were established by crossmating of these two strains of mice. When a 9,000 x g supernatant fraction prepared from the small intestine of M10/HITEC mouse was added to an incubation mixture for Ames test with Salmonella typhimurium TA98 strain to examine the mutagen-producing activity from aflatoxin B_1 (AEB_1) , the mutagen-producing activities of the 9,000 x g supernatant fraction from the small intestine was found to be 1.7-fold higher in the M10/HITEC mice than that seen with HITEC mice. Such a difference in the capacity to activate AFB1 was not seen with the 9,000 x g supernatant fraction from the kidney from M10/HITEC mice and HITEC mice. Male CYP3A7/HITEC mice of 8 weeks old were treated with a single i. p. injection of AFB1 (8 mg/kg body weight). The mutation of the introduced rpsL gene in the genomic DNA from the small intestine and the kidney was analyzed. The mutation frequency in the small intestine of M10/HITEC mice was significantly higher (p<0.05) than that of HITEC mice, while the mutation frequency in both strains was similar in the kidney. On the other hand, the mutation frequency of the rpsL gene from the kidney of M2/HITEC mice tended to be higher than that of HITEC mice. These results provide the first evidence that human CYP3A7 metabolically activate AFB1 in vivo.In conclusion, the CYP3A7/HITEC mice is a useful model to detect mutations in vivo induced by chemicals through the metabolic activations.

我们建立了6系携带人CYP 3A 7 cDNA的转基因小鼠，在M10小鼠中，CYP 3A 7在小肠中表达而在肾脏中不表达，而在M2小鼠中，CYP 3A 7在肾脏中表达。HITEC小鼠是一种转基因小鼠，用于体内检测各种化学品的致突变效力。CYP 3A 7/HITEC小鼠通过这两种小鼠品系的交叉交配建立。当将从M10/HITEC小鼠的小肠制备的9，000 × g上清液级分加入到用鼠伤寒沙门氏菌TA 98菌株进行艾姆斯试验的孵育混合物中以检查黄曲霉毒素B_1（AEB_1）的致突变剂产生活性时，发现在M10/HITEC小鼠中来自小肠的000 x g上清液级分比在HITEC小鼠中观察到的高1.7倍。在来自M10/HITEC小鼠和HITEC小鼠的肾脏的9，000 x g上清液部分中未观察到激活AFB 1的能力的这种差异。8周龄的雄性CYP 3A 7/HITEC小鼠用单次i.腹腔注射黄曲霉毒素B1（8 mg/kg体重）。分析了小肠和肾脏基因组DNA中引入的rpsL基因的突变。M10/HITEC小鼠小肠中的突变频率显著高于HITEC小鼠（p<0.05），而两个品系中肾脏中的突变频率相似。另一方面，M2/HITEC小鼠肾脏rpsL基因的突变频率往往高于HITEC小鼠。这些结果首次证明了人CYP 3A 7在体内代谢激活AFB 1，CYP 3A 7/HITEC小鼠是一种通过代谢激活来检测体内化学物质诱导突变的有用模型。

项目成果

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M. Chida 等人：“在日本人群中，一种新的 CYP2D6 等位基因变体 (CYP2D6/C8) 在外显子 5 中单个插入，与代谢不良表型相关”。

M. Chida et al.: "Genetic polymorphism of CYP2D6 in Japanese population." Pharmacogenetics. in press. (1999)

M. Chida 等人：“日本人群中 CYP2D6 的基因多态性。”

Yuichi Ando, Michihiro Chida, Kazuo Nakayama, hideo Saka and Tetsuya Kamataki: "The UGT1A1^*28 allele is relatively rare in a Japanese population" Pharmacogenetics. 8. 357-360 (1998)

Yuichi Ando、Michihiro Chida、Kazuo Nakayama、hideo Saka 和 Tetsuya Kamataki：“UGT1A1^*28 等位基因在日本人群中相对罕见”药物遗传学。

Yuichi Ando, Takayoshi Shimizu, Katsunori Nakamura, Taisei Mushiroda, Tetsuya Nakagawa, Takao Kodama and Tetsuya Kamataki: "Potent and non-specific inhibition of cytochrome P450 by JM216, a new oral platinum agent" Brit.J.Cancer. 78. 1170-1174 (1998)

Yuichi Ando、Takayoshi Shimizu、Katsunori Nakamura、Taisei Mushiroda、Tetsuya Nakakawa、Takao Kodama 和 Tetsuya Kamataki：“新型口服铂剂 JM216 对细胞色素 P450 的有效和非特异性抑制”Brit.J.Cancer。

K.Fujita, T.Kamataki et al.: "Establishment of a salmonella tester strain highly sensitive to mutagenic heterocyclic amines" Cancer Res.58. 1833-1838 (1998)

K.Fujita、T.Kamataki 等人：“建立对诱变杂环胺高度敏感的沙门氏菌测试菌株”Cancer Res.58。