1. Comparative effects of 17β-estradiol and phytoestrogens in the regulation of endometrial functions in the rodent uterus
- Author
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Giovanni Scambia, I. De Stefano, Manuela Fabrizi, D. Gallo, E. Mantuano, and Gianfranco Zannoni
- Subjects
medicine.medical_specialty ,Stromal cell ,PPARγ ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Uterus ,Phytoestrogens ,Biology ,Rats, Sprague-Dawley ,Endometrium ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,17β-estradiol ,Rat ,VEGFR-2 ,Cell Proliferation ,Estradiol ,Organ Size ,Hyperplasia ,medicine.disease ,Vascular Endothelial Growth Factor Receptor-2 ,Rats ,PPAR gamma ,Diabetes and Metabolism ,Ki-67 Antigen ,medicine.anatomical_structure ,chemistry ,Estrogen ,Sex steroid ,Ovariectomized rat ,Female ,hormones, hormone substitutes, and hormone antagonists ,Immunostaining - Abstract
The present study aimed at improving our understanding of the effects of 17beta-estradiol and phytoestrogens on the uterine tissue, by evaluating tissue-specific modulation of molecules related to cell-cycle control and angiogenesis. Specifically, the uterine expression of Ki67, peroxisome proliferator-activated receptor gamma (PPARgamma), and vascular endothelial growth factor receptor-2 (VEGFR-2), was examined by immunohistochemical analysis. Ovariectomized (OVX) rats were treated with either the vehicle, a phytoestrogen- containing soy extract (SSE) (100 mg/kg/day pos), or 17beta-estradiol (0.5 mg/kg/day pos); a sham control group (SHAM) was also included in the study. At necropsy, uteri were weighed, collected, and subsequently processed for histopathology or immunohistochemistry. SSE-treated rats did not show any significant change either in the weight or in histological features of the uterus when compared to OVX controls; the epithelial expression of proliferation marker Ki67 was seen to be significantly reduced, in comparison to both SHAM and OVX rats. Conversely, 17beta-estradiol significantly increased uterine weight, induced hyperplasia in the majority of rats, and enhanced Ki67 epithelial expression. The regulation of PPARgamma expression, reduced after ovariectomy, was similar in SSE- and 17beta-estradiol-treated rats, showing a further significant decrease in stromal immunostaining, in comparison to OVX controls. VEGFR-2 epithelial immunostaining, slightly reduced following ovariectomy, was highly increased on 17beta-estradiol treatment, while following SSE, the pattern of staining observed was similar to that of OVX controls. Data from this study show that PPARgamma and VEGFR-2 represent additional targets by which sex steroid estrogen and plant-derived phytoestrogens may, at certain doses, differentially regulate endometrial functions.
- Published
- 2008