| Project/Area Number |
16510047
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Risk sciences of radiation/Chemicals
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| Research Institution | Kansai Medical University |
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Principal Investigator |
SHIKATA Nobuaki Kansai Medical University, Faculty of Medicine, Associate Professor, 医学部, 助教授 (00121939)
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| Co-Investigator(Kenkyū-buntansha) |
TSUBURA Airo Kansai Medical University, Faculty of Medicine, Professor, 医学部, 教授 (90098137)
UEHARA Norihisa Kansai Medical University, Faculty of Medicine, Instructor, 医学部, 助手 (30368211)
YURI Takashi Kansai Medical University, Faculty of Medicine, Instructor, 医学部, 助手 (50330212)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Zeranol / Xenoestrogen / Mouse / Rat / Perinatal / Endocrine disruption / N-methyl-N-nitrosourea / Mammary / Endocrinedisruption / Cancer |
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| Research Abstract |
Effects of perinatal exposure to xenoestrogens were examined on female CD-1 mice, and found out that the estrogenic activity was high in mycoestrogen (zearalenone and zeranol), followed by phytoestrogens, and was low in industrial chemicals. Then, prepubertal female Sprague-Dawley rats were treated daily with either 0,0.1 or 10 mg/kg body weight of zeranol between 15 and 19 days of age. They were given 50 mg/kg body weight MNU at 28 days of age, and were monitored for occurrence of mammary tumors 【greater than or equal】1 cm in diameter. Zeranol did not affect body weight gain. At 28 days of age, zeranol-treated and -untreated rats showed similar development of reproductive organs and mammary glands. However, both low- and high-dose zeranol treatment caused significantly earlier vaginal opening, irregularity of estrous cycle (high frequency of prolonged estrus or prolonged diestrus) at 8 to 11 weeks of age, and anovulatory ovary (ovaries without newly formed corpora lutea). At 37 weeks of age, the high-dose zeranol-treated group exhibited increased relative uterine-ovarian weight, but mammary gland development was comparable to that of untreated rats. Mammary carcinogenesis was not affected by low- or high-dose zeranol treatment. Therefore, short-duration zeranol treatment in the prepubertal period severely damaged ovarian functions and structure, but mammary carcinogenesis was not affected. The present results suggest that ingestion of foods containing zeranol in the infantile period can cause dramatic endocrine disruption in later life.
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