MORPHOLOGICAL ACTION OF TAMOXIFEN IN THE ENDOMETRIUM OF PERSISTENT ESTROUS RATS

Background. The aim of this study was to evaluate the action of tamoxi fen on the endometrium in stales of chronic anovulation. Methods. Thir ty-eight rats inducted to persistent estrous (testosterone propionate) confirmed by hormonal colpocytology were divided into a control and a n experimental group; the latter received tamoxifen and had fragments of the uterine horns processed for morphological and morphometrical an alysis. Data were analysed statistically by the Mann-Whitney and Stude nt's t tests. Results. Our findings revealed minor uterine weight, epi thelial thickness; number of endometrial glands and low eosinophil cou nts in the group that received tamoxifen. These results were statistic ally significant. We often observed areas of metaplasic stratified squ amous epithelium between cylindrical epithelial cells in both groups. Conclusions. Our results indicate that antiestrogenic effect of tamoxi fen was only partial in persistent estrous, since there was no blockin g against the squamous metaplasia of the endometrium.