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Age and parity-dependent change in biological characteristics of rat mammary stem cells
https://repo.qst.go.jp/records/61318
https://repo.qst.go.jp/records/61318d31f582f-425c-4cf3-bb0d-d43051ad7cc0
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-03-31 | |||||
| タイトル | ||||||
| タイトル | Age and parity-dependent change in biological characteristics of rat mammary stem cells | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Shimada, Yoshiya
× Shimada, Yoshiya× 島田 義也 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | It is hypothesized that stem cells are the targets for carcinogenesis. If c ancer arises from stem cells, cancer risk would depend on population size an d susceptibility to carcinogens of stem cells . Study on A-bomb survivors sh ows clear age-related decline in the susceptibility to radiation-induced bre ast cancer. It is also known that women who undergo full-term pregnancy hav e a reduced lifetime risk of breast cancer. These results suggest that prot ection results from intrinsic effect of aging and parity on breast tissues. We here examined change in the biological characteristics of rat mammary st em cells (clonogens) with aging and parity. The results are as follows. (1) Total numbers of clonogens increased exponentially with a population doubli ng time of 4 days during pre-pubertal period. After puberty, it lengthened to 30 days. The total number of clonogens in abdominal and inguinal mammary glands of 2 week-old rats was 200, while that in 8 week-old and thereafter was more than 5,000. (2) The number of mammary clonogens in rats which und erwent pregnancy was less than 500, while that of nulliparous rats was 6,000 . (3) Prolactin treatment increased clonogen number by 8 folds in 8 week-ol d rats whereas it increased by just 2 folds in one year-old rats. (4) The su rviving fraction of clonogens before puberty after 5 Gy was 0.1, while it wa s 0.3 after puberty. These results suggest that population size, response t o prolactin and radiobiological characteristics of clonogens, which change i n age- and parity-dependent fashion, is associated with susceptibility to ra diation-induced mammary tumors. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 第83回日本生理学会大会 | |||||
| 発表年月日 | ||||||
| 日付 | 2006-03-30 | |||||
| 日付タイプ | Issued | |||||
