Projects / Programmes
Influences of environmental estrogens on the endocrine condition of animals
Code |
Science |
Field |
Subfield |
4.04.01 |
Biotechnical sciences |
Veterinarian medicine |
Morphology, physiology and animal reproduction |
Code |
Science |
Field |
B360 |
Biomedical sciences |
Animal physiology |
B750 |
Biomedical sciences |
Veterinary medicine: surgery, physiology, pathology, clinical studies |
estrogens, gonads, pituitary, central nervous system, thyroid gland, rats, in situ hybridization, confocal microscopy, G-protein coupled receptors, dopamine D2 receptor, TRH receptor, GnRH receptor
Researchers (5)
Organisations (1)
Abstract
Various substances from the environment, feeding-stuffs or medication can influence reproductive condition of animals. Known are estrogenic effects of some plants and pollutants in the environment, like polychlorinated biphenyls, alkylphenols and phthalates. Fitoestrogens in small concentrations stimulate reproductive system. However, estrogens have mitogenic activities that in the adults can cause increased frequency of cancer on gonads, genital tract and pituitary in the exposed objects. Pituitary and specific receptors on specialised cells and hormones synthesised and secreted by the pituitary are very important in the regulation of homeostasis of an organism. Responsiveness of the cell is equally influenced by the concentration of specific receptors and hormones. Estrogens synthesised in the organism influence the expression of some receptors in the pituitary and thus regulate the synthesis of some hormones and factors. Prolonged intake of estrogens from the environment can cause disbalance in the homeostasis of the organism and pathological changes in endocrine system. The purpose of our study is to investigate the changes caused by estrogenic substances in the pituitary, central nervous system (CNS), thyroid gland and gonads. Studied are the variations in the expression of specific RNAs caused by estrogens in different reproductive stages and after treatment of animals with various estrogenic compounds. New-born rats are treated with oktylphenol and diethylstilbestrol. In the pituitary and CNS we are following mainly the changes in the expression of genes encoding D2-R, TRH-R (controlling the secretion of prolactin) and GnRH-R (controlling function of gonads). Serum concentrations of T3 and T4 are also measured. Changes in the cell and the mechanisms of the receptor action and internalization after ligand binding are studied in the cells transfected with cDNAs for receptors containing specific epitope tags that allow imunocytochemical studies using light, confocal and electron microscopy.