Archive for the ‘Estradiol’ Category - Part 2

Diethylstilbestrol Versus Estradiol: RESULTS(3)

In the uterine-adjacent region of the same sections, histology of the luminal epithelium was distinct from that observed in the ectocervical regions but mimicked what we had found previously in sections taken from the midregion of the uterus in 5-day-old hamsters. Specifically, in the lower uterine region adjacent to the cervix (Fig. 5, right), the […]

Diethylstilbestrol Versus Estradiol: RESULTS(2)

They provide visual confirmation that both neonatal treatment regimens enhanced cervical growth as early as Day 3, but then (Day 5 to Day 21) that response was more dramatic in the neonatally DES-exposed animals than in the neonatally E2-exposed animals. Another anatomical feature that can be appreciated in Figures 2-4 (and in subsequent figures that […]

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 […]

Diethylstilbestrol Versus Estradiol: MATERIALS AND METHODS(3)

The harvested tracts were ultimately divided into cervix, uterine horns, and oviduct/ovarian (when present) regions and then embedded in paraffin. For the present study, 4- to 5-^m midfrontal sections from the cervical region of the tracts were processed for light microscopy using standard hematox-ylin-and-eosin staining. At least four sections cut from each of the cervices […]

Diethylstilbestrol Versus Estradiol: MATERIALS AND METHODS(2)

Ovariectomy and placement of E2 pellets were performed at 21 days of age under pentobarbital-induced anesthesia. The pellets were inserted s.c. between the shoulder blades and consisted of a plugged Silastic (Dow Corning Corp., Midland, MI) tube (open lumen length, 1.0 cm; inner diameter, 1.57 mm; outer diameter, 2.41 mm) filled with crystalline E2. According […]

Diethylstilbestrol Versus Estradiol: MATERIALS AND METHODS(1)

Animal Treatment Treatment of neonates, ovariectomy, chronic E2 stimulation, anesthesia, and killing by decapitation were performed according to established protocols in an Association for Assessment and Accreditation of Laboratory Animal Care-accredited facility according to the Guiding Principles for the Care and Use of Research Animals promulgated by the Society for the Study of Reproduction. Timed […]

Diethylstilbestrol Versus Estradiol: INTRODUCTION(4)

Because few direct, in vivo comparisons of perinatal endocrine-disruptive potency have been made between the synthetic estrogen, DES, and the primary natural estrogen, E2, the archive includes tissues from groups of hamsters that were treated neonatally with each of the two estrogens. We have already used this archive for an extensive histo-morphological analysis in the […]

Diethylstilbestrol Versus Estradiol: INTRODUCTION(3)

Closer examination of the histopathological lesions that developed in the hamster uterus following neonatal DES exposure and later stimulation with E2 revealed that the hyperplastic endometrial epithelium also displayed intense apoptosis according to morphological (apoptotic bodies), biochemical (internucleosomal DNA fragmentation), and histochemical (in situ labeling of free 3′ DNA ends) evidence. According to Northern blot […]

Diethylstilbestrol Versus Estradiol: INTRODUCTION(2)

Subsequent analysis regarding the early stage of the phenomenon revealed that neonatal DES exposure induced both acute and persistent changes in mitotic activity, organization, and dimensions of individual tissue compartments in the immature (prepubertal) uterus. To investigate the later stage of the phenomenon, we used mature animals that had been ovariectomized and then chronically stimulated […]

Diethylstilbestrol Versus Estradiol: INTRODUCTION(1)

The synthetic estrogen diethylstilbestrol (DES) is an established perinatal endocrine disruptor (ED) in both humans and experimental animals. Of the rodent species used to evaluate the potency and mechanism of action of DES and other putative EDs, the Syrian golden hamster (Mesocricetus auratus) offers some unique advantages. These advantages have been reviewed recently and include […]

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