Study of the action of tamoxifen on the mammary gland epithelium of premenopausal patients by lysosome quantification.

Tamoxifen is an antiestrogen drug widely utilized for the adjuvant hormonal treatment of breast carcinoma. Its use in the primary prophylaxis of this disease is currently being proposed. Although the drug has few side effects, its precise action on breast tissue that has not undergone neoplastic transformation has not been fully elucidated. This prospective, randomized study assessed the estrogen activity of tamoxifen on the mammary gland epithelium of premenopausal patients using a quantitative analysis of mammary epithelium lysosome identified by the cytochemical technique of GOMORI for acid phosphatase and by light microscopy. Tamoxifen significantly increased the number of lysosomes only during the secretory phase of the menstrual cycle. We concluded that the early effect of the drug on normal mammary tissue is synergistic with the effect of estrogen during the premenopausal period.

Morphological action of tamoxifen in the endometrium of persistent estrous rats.

BACKGROUND: The aim of this study was to evaluate the action of tamoxifen on the endometrium in states of chronic anovulation. METHODS: Thirty-eight rats inducted to persistent estrous (testosterone propionate) confirmed by hormonal colpocytology were divided into a control and an experimental group; the latter received tamoxifen and had fragments of the uterine horns processed for morphological and morphometrical analysis. Data were analysed statistically by the Mann-Whitney and Student's t tests. RESULTS: Our findings revealed minor uterine weight, epithelial thickness; number of endometrial glands and low eosinophil counts in the group that received tamoxifen. These results were statistically significant. We often observed areas of metaplasic stratified squamous epithelium between cylindrical epithelial cells in both groups. CONCLUSIONS: Our results indicate that antiestrogenic effect of tamoxifen was only partial in persistent estrous, since there was no blocking against the squamous metaplasia of the endometrium.

[Morphologic and morphometric aspects of the mammary gland of normal and oophorectomized rats treated with metoclopramide]. / Aspectos morfológicos e morfométricos da glândula mamária de ratas normais e ooforectomizadas tratadas com metoclopramida.

The authors performed an optical microscope morphologic and morphometric study of the mammary glands of rats treated and untreated with metoclopramide during estrous and after ovariectomy. They observed that in the group of normal rats treated with the drug the glands were well developed and contained secretion in the lumen of their ducts and alveoli. In the group of rats submitted to ovariectomy and treated with metoclopramide, however, the glands were atrophied and had the same aspect of glands during estrous. These findings are in agreement with the morphometric study, which showed a statistically significant increase of parenchyma in the group of normal treated rats as compared to the other groups and, further, a higher number of alveoli with secretion.