Verhoeven G, Vandoren G, Heyns W, Kühn E R, Janssens J P, Teuwen D, Goddeeris P, Lesaffre E, De Moor P
J Endocrinol. 1982 Dec;95(3):357-68. doi: 10.1677/joe.0.0950357.
The effects of neonatally administered steroids on the sensitivity of the mammary gland to tumour induction by 7, 12-dimethylbenz (alpha) anthracene was studied as a model for delayed (de) differentiating effects of steroid hormones. Immediately after birth male and female rats were gonadectomized and treated with testosterone, oestradiol or oil. Control animals were left intact. On day 45 all the gonadectomized animals and some of the control animals received an implant which delivered continuous low levels of oestradiol. The carcinogen was administered on day 55. The administration of an oestradiol implant, which increased prolactin levels in all animals, markedly reduced tumour incidence in intact female rats and increased tumour incidence in intact male rats. Neonatal administration of testosterone or oestradiol did not significantly influence tumour incidence, histopathology or oestradiol responsiveness in neonatally gonadectomized rats but tended to decrease tumour animals suggests that the effects observed by other authors in intact rats are mediated by changes in gonadal secretions. It is concluded that the hormonal environment during and after tumour induction plays a major role in the development of 7, 12-dimethylbenz (alpha) anthracene-induced mammary carcinomas.
作为类固醇激素延迟（去）分化作用的一个模型，研究了新生期给予类固醇对乳腺对7,12-二甲基苯并（α）蒽诱导肿瘤敏感性的影响。出生后立即对雄性和雌性大鼠进行性腺切除，并用睾酮、雌二醇或油进行处理。对照动物不做处理。在第45天，所有性腺切除的动物和一些对照动物接受了一个能持续释放低水平雌二醇的植入物。在第55天给予致癌物。给予雌二醇植入物后，所有动物的催乳素水平均升高，这显著降低了未处理雌性大鼠的肿瘤发生率，而增加了未处理雄性大鼠的肿瘤发生率。新生期给予睾酮或雌二醇对新生期性腺切除大鼠的肿瘤发生率、组织病理学或雌二醇反应性没有显著影响，但倾向于减少肿瘤动物数量，这表明其他作者在未处理大鼠中观察到的效应是由性腺分泌物的变化介导的。结论是，肿瘤诱导期间及之后的激素环境在7,12-二甲基苯并（α）蒽诱导的乳腺癌发生发展中起主要作用。
