The effect of hyperstimulation on transforming growth factor beta(1) and beta(2) in the rat uterus: possible consequences for embryo implantation.
OBJECTIVE
To investigate the effect of exogenous gonadotropins on the expression of transforming growth factor (TGF) beta(1) and beta(2) in the rat uterus and its consequences for successful embryo implantation.


METHODS
Controlled experimental research study.


METHODS
School of Anatomical Sciences, University of the Witwatersrand.


METHODS
Thirty-six adult, virgin, female Sprague-Dawley rats and two fertile males.


METHODS
Follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG) were superimposed upon the normal hormonal milieu of normal, cycling female rats before mating. Uterine tissue was collected at peri-implantation stages (i.e., at 4.5, 5.5, and 6.5 days) after mating. Enzyme-linked immunosorbent assay (ELISA) was performed to estimate the blood estrogen and progesterone levels, and immunohistochemistry was performed to localize the TGF-beta(1) and TGF-beta(2) in the uterus.


METHODS
Hyperstimulation affecting the expression of both TGF-beta(1) and TGF-beta(2) during the peri-implantation period.


RESULTS
The release of ovarian steroids was altered, causing a change in the endogenous hormonal environment. A marked increase in the expression of TGF-beta(2) was distinct in the glandular epithelium. Expression of both TGF-beta(1) and TGF-beta(2) was weaker in the subluminal stroma when compared with the deeper stromal region.


CONCLUSIONS
Hyperstimulation with exogenous hormones affects the expression of both TGF-beta(1) and TGF-beta(2), which may contribute to the disruption of the endometrial environment required for successful embryo implantation.
Jovanović
Aleksandra
A
Embryonic Differentiation and Development Research Programme, School of Anatomical Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, South Africa. aleksandra.jovanovic@wits.ac.za
Kramer
Beverley
B
D000818:Animals; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D010064:Embryo Implantation / Q000187:drug effects*; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D007150:Immunohistochemistry; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D053781:Transforming Growth Factor beta2 / Q000378:metabolism*; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; C508962:Tgfb1 protein, rat; C509043:Tgfb2 protein, rat; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone