Evaluation of morphology, apoptosis, and cell proliferation of the uterus in postmenopausal women.

Background: The aim of this study was to evaluate the morphology (atrophy and fibrosis), apopto-sis, and cell proliferation in the uterine wall. The research material came from postmenopausal women who had undergone hysterectomy due to uterine myomas or prolapse of the reproductive organ and were not taking menopausal hormone therapy (MTH).

Material and methods: The collected material was divided into three groups. Group I (n=18) con-sisted of uterine sections taken 1 to 5 years after the last menstruation, Group II (n=17) 6 to 10 years after the last menstruation, and Group III (n=15) over 11 years after the last menstruation. To assess morphology and fibrosis, the uterine sections were subjected to hematoxylin and eosin (HE) staining and to Mallory's staining. In addition, we performed a histochemical examination to identify apopto-sis in endometrial and myometrial cells using the TUNEL method. An immunohistochemical analysis of endometrial and myometrial cells was also performed to detect the location of the proliferating cell nuclear antigen (PCNA).

Results: Differences in apoptosis were only found in the myometrium between Group I and Group III, and were strongest in Group I myometrial cells, and weakest in Group III. Neither the endome-trium nor the myometrium showed statistically significant differences in the overall percentage of PCNA(+) cells between groups.

Conclusion: Morphological changes in the endometrial and myometrial layers of postmenopausal uteri increased with time since the last menstruation.