Specifically, the luminal epithelium in the lower uterine region adjacent to the cervix (Fig. 8, right) was 1) low cuboidal in control animals, 2) slightly taller and pseudostratified in E2-treated animals, and 3) extremely tall in neonatally DES-exposed animals. In addition, the cell’s basal aspects were difficult to distinguish from the underlying stromal tissue compartment in neonatally DES-treated animals.
Adult, Ovariectomized, and Estrogen-Replaced Animals
Previously, we used the strategy of prepubertal ovariectomy plus sustained E2 replacement (O+E2) to demonstrate that neonatal DES, but not neonatal E2, treatment directly and permanently disrupts estrogen responsiveness in the adult hamster uterus. canadian neighbor pharmacy
Under the same endocrine-manipulation conditions, the scenario in the hamster cervix was somewhat different. Figure 9 shows the influence of neonatal DES versus E2 treatment on body weight, absolute size (diameter) of the cervix, and size of the cervix normalized to body weight in animals that were ovariectomized on Day 21 of age and then chronically stimulated with E2 until 1 or 2 mo of age. In contrast to the trend noted above in the intact adult animals, body weight in the O+E2 animals (Fig. 9A) was slightly increased (not statistically significant) in the neonatally E2-treated group but slightly decreased in the neonatally DES-treated group (statistically significant only at 2 mo).
FIG. 9. Effects of neonatal DES versus E2 treatment on body weight, absolute size of the cervix, and normalized size of the cervix in ovari-ectomized and estrogen-replaced adult hamsters. Following injection on the day of birth (Day 0) with vehicle alone (control [C]) or 100 |xg of either E2 (E) or DES (D), female animals at 21 days of age underwent ovariectomy plus implantation with an E2-releasing pellet. Then at the indicated days of age, they were weighed (A), and their reproductive tracts were fixed, separated into various regions, and processed for standard paraffin embedding, sectioning, and hematoxylin and eosin staining. Cervical diameters were measured at the uterine/endocervix junction of midfrontal tissue sections (see Fig. 2) and were expressed both on an absolute basis (B) and after being normalized to the animal’s body weight (C). Values represent the mean ± SEM (n = 3; errors bars not shown where variability was so small as to be masked by the data point), and means that are significantly different (P < 0.05) from each other at each time point are indicated by different lowercase letters.
FIG. 10. Cervical histology in ovariectomized and estrogen-replaced adult hamsters. Shown are low-magnification micrographs of midfrontal sections of the cervical regions positioned with their cranial (uterine-adjacent) aspect to the right and caudal (vaginal-adjacent) aspect to the left. The tissues are from hamsters that had been injected on the day of birth with vehicle alone (control [CON]) or containing 100 |xg of either E2 or DES and then had undergone ovariectomy plus implantation of an E2-releasing pellet at 21 days of age, and they are representative of the histology observed in the cervices from three separate animals at each age.