Scanning electron microscopy of the effect of short-term hormonal therapy on postmenopausal endometrium

Review of the endometrial safety during intravaginal treatment with estriol

To gain more insight into whether intravaginal treatment of local urogenital complaints with the mild-acting oestrogen estriol is capable of inducing proliferation of the endometrium, the results of the clinical studies that have been published over the years have been pooled. Of a total of 19 studies that initially had been selected, four were excluded from the analysis because no baseline biopsies were available, two because endometriae had been evaluated using methods other than with histology, and one study because a sustained-release preparation was used. Pooling of 12 studies (214 subjects) revealed a reasonable amount of long-term data on intravaginal estriol treatment with 61 evaluable biopsies after 6 months and 58 after 12 months. In addition, 13 biopsies were available after 2 years. It appeared that intravaginal estriol treatment using the recommended dosages did not result in endometrial proliferation. All 337 post-baseline biopsies that have been reported in the literature were classified as atrophic. It can be concluded that single daily treatment with intravaginal estriol in the recommended doses in postmenopausal women is safe and without an increased risk of endometrial proliferation or hyperplasia. Consequently, there is no need to add sequential progestogens with these preparations and no withdrawal bleedings will be induced.

Upper genital tract abnormalities in the Syrian hamster as a result of in utero exposure to diethylstilbestrol. II. Scanning electron microscope analysis of endometrium cell surfaces

Using scanning electron microscopy (SEM), we show that an in utero exposure to diethylstilbestrol (DES) will induce endometrial abnormalities postnatally. These changes are magnified when a subsequent postnatal DES treatment is given. More specifically, changes in cell surface morphology are associated with alterations in cell size and shape (from columnar to cuboid/squamous), and in microvilli and mucus secretion. Uteri from hamsters treated postnatally with DES and derived from normal (CD) or DES-treated mothers (DD) show that accumulated mucoid secretion products are not expelled in the uterine lumen but are "stored" in cystic dilated glandular spaces of the fibrocellular stroma of polyps and papillae filling the uterine lumen. Uteri from female hamsters that have been prenatally treated with DES (DC) show endometrial mucosal crypts containing mucus and other cell debris including migrating granulocytes. In all cases, DES-treated uteri show mucosal cell surface pleomorphism in the sequence DD greater than CD greater than DC Merocrine and/or cystic secretions were observed. Microvilli cover cell surfaces and include some rare and peculiar long microvillous growth. In contrast, DC hypoplastic uteri present no secretory activity. Structures similar to those described for CD uteri can be observed only after 250 days of age in DC uteri. This report confirms and complements previous observations, favoring the choice of the hamster as an animal mode for the study of endometrial carcinogenesis.

The response of the uterine surface to ovarian hormones in the aged rat

By scanning electron microscopy uterine luminal epithelium of the rat was studied to determine whether aging alters ovarian hormone stimulated ultrastructural changes in that portion of the endometrial surface into which implantation takes place in the younger animal. Results show that in the aged rat this surface differentiates in response to ovarian hormones in a manner qualitatively similar to that which occurs in the young animal. Epithelial cells of ovariectomized rats, both young and aged, were polygonal in outline, flattened, or even somewhat concave, and had short microvilli. Following estrogen treatment cells of both groups were round or oval and bulged into the lumen. Cells of young rats were covered with long microvilli. Most cells of aged rats had microvilli of equal or greater length; a small number of epithelial cells had fewer and shorter microvilli. Cells of progesterone-treated young and aged animals both were covered with short microvilli and bore membrane protrusions. The protrusions varied in size, shape and numbers both within and between age groups. These findings suggest that differences in the surface ultrastructure of the aged uterus reflect age-related changes in hormone levels.

Scanning electron microscopy of the responses of postmenopausal endometrium to treatment with estriol and estriolprogesterone

Seven postmenopausal women are given estriol orally in a daily dose of 1 mg x 2 or 5 mg x 2 for 14 or 28 days and 2 women were sequentially treated with 5 mg x 2 of estriol orally for 21 days, with the addition of 0.2 g x 2 of progesterone rectally in the last 7 days. Three women served as controls. Scanning electron microscopy revealed that the former treatment with estriol was sufficient to produce an estrogen response in the non-ciliated uterine epithelial cells, which developed many long microvilli, sometimes arranged in tufts. The sequential treatment with initial estriol priming followed by estriol and progesterone combined resulted in a slight secretory transformation of the uterine epithelium, observed as an increase in size and number of the apical protrusions of the cells.