Morphological Features of Endometrium in Women of Reproductive Age and Female Rats: Comparative Characteristic of Morphometric Study

Due to the active introduction of new reproductive technologies in obstetrics and the study of the causes of infertility, the need for experimental modeling of these pathologies is growing. However, a comparison of morphological pictures of normal endometrium in rats and women was practically not carried out. The purpose of the study was to conduct morphological parallels and to determine common and distinct structural changes in the uterine mucosa in the proliferation phase. To establish the peculiarities of the morphometric parameters of the stromal and epithelial components of the normal endometrium of the proliferative phase in women of reproductive age and female rats. Material and methods. A morphometric analysis of human endometrium of the proliferative phase was conducted in 15 women of reproductive age, and 5 female rats of the proestrus phase of the animal. Histologic coloration of sections was done with the help of hematoxylin-eosin. The main morphometric parameters were the diameter of the endometrium glands, the thickness of the glands wall, the ratio of the cross section area of the glands to the area of the endometrium. Results and discussion. The histological picture of the late stage of proliferative endometrium of females and female rats had the following characteristics: thickening of the functional layer with loss of stratification. The endometrial glands in the cross-section had a generally rounded form, longitudinal-vortex, lined with a high cylindrical epithelium with even apical edges. There was one or two sections of the verticular thin-walled arteries in the stroma. The distinctive morphological features of women's endometrium were mitotic cells, a large number in relation to the stroma of the glandular components, loose stroma with focal multiple vacuoles, whereas for female rats there was a characteristic stroma, and glandular components were few. The morphometric indices of endometrium when compared to them had the following features. The glands diameter of the functional layer of the rat's uterus was 39.50 ± 7.46 μm, which was less than the human endometrium glands - 43.73 ± 13.80 μm (p = 0.075). Visually, there is a smaller number of endometrium glands in rats compared with the human endometrium, as evidenced by the ratio of the cross-sectional area of the glands to the endometrium area. Thus, in rats this indicator was 4.80%, and in human preparations it was 10.21%, respectively (p <0.001). Conclusions. The rat's endometrium diameter is less than that of a human endometrium, but this difference is not statistically significant. The thickness of the rat's endometrium wall is significantly lower than the human endometrial glands wall thickness. The ratio of the cross-sectional area of the glands to rat's endometrium is significantly lower than the ratio of the cross-sectional area of the glands to human endometrium, which may indicate a smaller number.