Related Experiment Videos
Thyroid gland function in ovariectomized ewes exposed to phytoestrogens.
Andrzej Madej1, Elisabeth Persson, Torbjörn Lundh
1Department of Animal Physiology, Centre for Reproductive Biology in Uppsala, Swedish University of Agricultural Sciences (SLU), PO Box 7045, S-750 07, Uppsala, Sweden. andrzej.madej@djfys.slu.se
Summary
Phytoestrogens from red clover silage increased thyroid hormone secretion and estrogen receptor alpha (ER alpha) immunoreactivity in ovariectomized ewes. This suggests plant-derived compounds can impact thyroid function and receptor expression.
Area of Science:
- Endocrinology
- Animal Science
- Reproductive Biology
Background:
- Phytoestrogens are plant compounds mimicking estrogen.
- Their effects on thyroid function and estrogen receptors are not fully understood.
Purpose of the Study:
- To investigate phytoestrogen effects on thyroid hormone secretion.
- To assess changes in thyroid estrogen receptor alpha (ER alpha) immunoreactivity.
- To examine thyroid gland morphology in response to phytoestrogen exposure.
Main Methods:
- Ovariectomized ewes were fed red clover silage containing phytoestrogens.
- Plasma thyroid hormones (T3) and ER alpha immunoreactivity were measured.
- Thyroid gland histology and morphometry were analyzed via immunohistochemistry.
Main Results:
- Red clover silage significantly increased plasma total T3 and free T3 concentrations.
- Thyroid follicle cross-sectional area showed a tendency to increase.
- ER alpha immunoreactivity was significantly stronger in phytoestrogen-exposed ewes.
Conclusions:
- Daily phytoestrogen intake stimulates thyroid hormone secretion in ewes.
- Phytoestrogens may influence thyroid follicle size and ER alpha expression.
- These findings highlight potential endocrine-disrupting effects of dietary phytoestrogens.