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Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens.

Perniconi SE, Simões Mde J, Simões Rdos S, Haidar MA, Baracat EC, Soares JM - Clinics (Sao Paulo) (2008)

Bottom Line: The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01).However, the difference in epithelium thickness between the GE0.5mg and GE1mg groups was only slight.Our data suggest that CEE at a dose of 2 mg/kg may induce marked proliferation of rat ovarian epithelium.

View Article: PubMed Central - PubMed

Affiliation: Morphology Department, UNIFESP, São Paulo, SP, Brazil.

ABSTRACT

Objective: To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats.

Design: Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 microg/kg; GE0.5mg, group receiving CEE at 500 microg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program.

Results: In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However, the difference in epithelium thickness between the GE0.5mg and GE1mg groups was only slight.

Conclusion: Our data suggest that CEE at a dose of 2 mg/kg may induce marked proliferation of rat ovarian epithelium.

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Photomicrography showing the cortical region of ovaries belonging to the different study groups: A) GPROP, B) GE50μg, C) GE0.5mg, D) GE1mg and E) GE2mg. The arrows in (D) and (E) indicate thickened superficial epithelia. H.E 260X
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f2-cln63_3p0381: Photomicrography showing the cortical region of ovaries belonging to the different study groups: A) GPROP, B) GE50μg, C) GE0.5mg, D) GE1mg and E) GE2mg. The arrows in (D) and (E) indicate thickened superficial epithelia. H.E 260X

Mentions: No rats died during the experiment. The OSE was of simple cuboidal shape in all animals in the GPROP and GE0.05mg groups. However, as the estrogen dose increased, the lining of the epithelium thickened. This thickening was most obvious in the GE2mg group, where the epithelium was observed to be pseudo-stratified or stratified (Fig. 2). The percentage of rats with thickened ovarian superficial epithelium was 10%, 40%, and 90%, in the GE0.5mg, GE1mg, and GE2mg groups, respectively. The ovarian stroma contained a large number of interstitial cells in all groups receiving CEE. These cells were most numerous in the GE1mg and GE2mg groups (Fig. 2). The percentage of rats with increased interstitial cells was 70% and 100% in GE1mg and GE2mg, respectively. In these two groups, we also noticed leukocyte infiltration in several ovarian follicles, suggesting follicular degeneration. This phenomenon in G2mg (80% of the rats) was more pronounced than other groups . We did not observe significant differences in the number of ovarian follicles or in the number of corpora lutea among the groups under investigation.


Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens.

Perniconi SE, Simões Mde J, Simões Rdos S, Haidar MA, Baracat EC, Soares JM - Clinics (Sao Paulo) (2008)

Photomicrography showing the cortical region of ovaries belonging to the different study groups: A) GPROP, B) GE50μg, C) GE0.5mg, D) GE1mg and E) GE2mg. The arrows in (D) and (E) indicate thickened superficial epithelia. H.E 260X
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2664246&req=5

f2-cln63_3p0381: Photomicrography showing the cortical region of ovaries belonging to the different study groups: A) GPROP, B) GE50μg, C) GE0.5mg, D) GE1mg and E) GE2mg. The arrows in (D) and (E) indicate thickened superficial epithelia. H.E 260X
Mentions: No rats died during the experiment. The OSE was of simple cuboidal shape in all animals in the GPROP and GE0.05mg groups. However, as the estrogen dose increased, the lining of the epithelium thickened. This thickening was most obvious in the GE2mg group, where the epithelium was observed to be pseudo-stratified or stratified (Fig. 2). The percentage of rats with thickened ovarian superficial epithelium was 10%, 40%, and 90%, in the GE0.5mg, GE1mg, and GE2mg groups, respectively. The ovarian stroma contained a large number of interstitial cells in all groups receiving CEE. These cells were most numerous in the GE1mg and GE2mg groups (Fig. 2). The percentage of rats with increased interstitial cells was 70% and 100% in GE1mg and GE2mg, respectively. In these two groups, we also noticed leukocyte infiltration in several ovarian follicles, suggesting follicular degeneration. This phenomenon in G2mg (80% of the rats) was more pronounced than other groups . We did not observe significant differences in the number of ovarian follicles or in the number of corpora lutea among the groups under investigation.

Bottom Line: The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01).However, the difference in epithelium thickness between the GE0.5mg and GE1mg groups was only slight.Our data suggest that CEE at a dose of 2 mg/kg may induce marked proliferation of rat ovarian epithelium.

View Article: PubMed Central - PubMed

Affiliation: Morphology Department, UNIFESP, São Paulo, SP, Brazil.

ABSTRACT

Objective: To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats.

Design: Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 microg/kg; GE0.5mg, group receiving CEE at 500 microg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program.

Results: In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However, the difference in epithelium thickness between the GE0.5mg and GE1mg groups was only slight.

Conclusion: Our data suggest that CEE at a dose of 2 mg/kg may induce marked proliferation of rat ovarian epithelium.

Show MeSH