THE EFFECT OF ENDOCRINE CHANGES, OF IRRADIATION AND OF ADDITIONAL TREATMENT OF THE SKIN ON THE INDUCTION OF TUMOURS IN THE FEMALE GENITAL TRACT OF RATS BY CHEMICAL CARCINOGENS
Ovariectomy reduced the incidence of vaginal tumors after intravaginal application of 9,10-dimethyl-1,2benzanthracene (DMBA), and administration of oestrogen or of progesterone raised the incidence of tumors only slightly. Repeated whole-body exposures to x rays also lowered the rate of tumor incidence after painting and so to a lesser extent did repeated pelvic irradiation of virgin rats and the application of DMBA to an additional dorsal skin region. In surgical castrates adrenalectomy or repeated pelvic irradiation restored the level of tumor incidence to that of intact and pregnant rats. Three levels of vaginal tumor incidence were found, and the distribution of tumor types and the length of the average induction time varied with the level: at the lowest level there were only sarcomas, at the intermediate level fibromas and presarcomatous lesions were found in addition to the sarcomas; and at the highest level the incidence of sarcomas is increased and epithelial tumors appear. Tumor induction in the vulva is not affected by castration, radiation, or hormone treatment but varies at certain dose levels with the dose of the carcinogen. (auth)
- Research Organization:
- Strangeways Research Lab., Cambridge, Eng.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-15-007207
- OSTI ID:
- 4104614
- Journal Information:
- Brit. J. Cancer, Vol. Vol: 14; Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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