Diethylstilbestrol Versus Estradiol: RESULTS(1)

Prepubertal Animals

Effects 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 prepubertal animals are shown in Figure 1. The data in Figure 1A show that neither of the two neonatal treatment regimens had a significant effect on animal growth from Days 1 to 21. Consequently, neonatal treatment effects on cervical growth were comparable whether values were expressed on an absolute (Fig. 1B) or a normalized (Fig. 1C) basis. In both cases, cervical growth was significantly enhanced by Day 3 in the neonatal E2 and DES treatment groups. Thereafter, the enhanced cervical growth response was more dramatic in the neonatally DES-exposed groups than in the neonatally E2-exposed groups (all DES vs. E2 group differences, except for the Day-21 values, were statistically significant).

To further illustrate the differential treatment effects on prepubertal growth of the cervix, low-magnification views are shown of representative tissue sections from control animals (Fig. 2) and from animals that were treated neonatally with E2 (Fig. 3) or with DES (Fig. 4).
Fig1Diethylstilbestrol Versus-1
FIG. 1. Effects of neonatal DES versus E2 treatment on body weight, absolute size of the cervix, and normalized size of the cervix in prepubertal animals. 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 the indicated days of age 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/endocervical 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 are not shown where the 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.

Fig2Diethylstilbestrol Versus-2
FIG. 2. Cervical histology in control, prepubertal hamsters. Low-magnification micrographs of midfrontal cervical sections 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 (Day 0) with vehicle alone (control [CON]) and are representative of the histology observed in the cervices from three separate animals at each age.

Fig3Diethylstilbestrol Versus-3
FIG. 3. Cervical histology in prepubertal hamsters following neonatal E2 treatment. Low-magnification micrographs of mid-frontal cervical sections positioned with their cranial (uterine-adjacent) aspect to the right and caudal (vaginal-adjacent) aspect to the left. The tissues are from animals injected on the day of birth with vehicle containing 100 ^g of E2.

Fig4Diethylstilbestrol Versus-4
FIG. 4. Cervical histology in prepubertal hamsters following neonatal DES treatment. Low-magnification micrographs of midfrontal cervical sections positioned with their cranial (uterine-adjacent) aspect to the right and caudal (vaginal-adjacent) aspect to the left. The tissues are from animals injected on the day of birth with vehicle containing 100 ^g of DES.

Category: Estradiol

Tags: cervix, developmental biology, estradiol, female reproductive tract, toxicology