Increase of estrogen receptor level by thyroxine in estrogen dependent pituitary tumor (MtT/F84) in rats.
A rat transplantable pituitary tumor, MtT/F84, grows much faster in E2 treated rats than in normal females, but is much retarded in thyroidectomized rats. Triiodothyronine (T3) administration in a drinking water increased the tumor growth by the dose dependent manner. The tumor contained both estrogen receptor (ER) and T3 receptor. ER levels both in the nuclei and cytosols elevated 2 to 3 times by the T3 administration compared to those of control. E2 administration promotes the growth of MtT/F84 through elevation of nuclear ER level. T3 may directly elevate cellular ER level and thus it may enhance estrogenic actions including the tumor growth.
Fujimoto
N
N
Department of Cancer Research, Hiroshima University, Japan.
Roy
B
B
Watanabe
H
H
Ito
A
A
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004343:Drug Implants; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D013965:Thyroidectomy; D013974:Thyroxine / Q000494:pharmacology*
D004343:Drug Implants; D011960:Receptors, Estrogen; D011988:Receptors, Thyroid Hormone; D004958:Estradiol; D013974:Thyroxine