Effects of oestradiol benzoate on the pituitary-thyroid axis of male and female rats
Boado, R.; Ulloa, E.; Zaninovich, A.A.
Acta Endocrinologica 102(3): 386-391
1983
ISSN/ISBN: 0001-5598 PMID: 6829263 Document Number: 210876
In the present work the effects of estradiol benzoate (EB) on pituitary and plasma concentrations of TSH, plasma T4 T4). In both male and female rats the 10 and 25 .mu.g doses of EB produced a significant decrease in pituitary TSH content; this effect was more pronounced when the 25 .mu.g dose was given over 30 days. Plasma T4 decreased significantly; plasma T3 was moderately elevated in all groups (not significantly) and significantly increased in female rats treated with 25 .mu.g EB (P < 0.01). EB induced a marked depression of intrapituitary TSH, probably due to a decrease in synthesis, without affecting the release of TSH into the circulation. Moreover, EB accelerated peripheral T4 kinetics and thyroid gland activity, albeit to a moderate degree.