ISSN:
1471-0528
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
The effect of oestrogen administration on plasma levels of luteinizing hormone (LH) in twelve euthyroid and twelve thyrotoxic postmenopausal women was studied to further elucidate the changes in gonadal steroids and gonadotrophic hormone levels which have been previously reported in thyrotoxic women. Preliminary experiments showed that 125 μg. of oestradiol benzoate (approximately 2 μg./kg. of bodyweight) was the smallest effective dose which significantly reduced LH levels in euthyroid postmenopausal women. This dose was, however, ineffective in reducing LH levels in thyrotoxic postmenopausal women. Similar results were obtained with 250 μg. (approximately 4 μg./kg. of bodyweight) diethylstilboestrol which does not bind to sex hormone binding globulin (SHBG), thus showing that the results could not be attributable to the high levels of SHBG which have been shown in thyrotoxicosis. The diminished sensitivity of the hypothalamo-pituitary system of thyrotoxic postmenopausal women to oestrogen which this study shows lend further support to the hypothesis that changes in gonadal steroid and gonadotrophic hormone levels in thyrotoxicosis may be due to blunting of the feedback mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-0528.1974.tb00383.x
