Banu Sakhila K, Govindarajulu P, Aruldhas Michael M
Department of Endocrinology, Dr ALM PG Institute of Basic Medical Sciences, University of Madras, Chennai Taramani 600113, India.
Steroids. 2002 Dec;67(13-14):1007-14. doi: 10.1016/s0039-128x(02)00063-6.
Thyroid gland is one of the non-classical target organs for sex steroids. Presence of androgen and estrogen receptors in the neoplastic and non-neoplastic thyroid glands of mammalian species is well documented. The aim of the present study is to elucidate the changes in serum and thyroidal sex steroids, and their receptors in the thyroid gland of rats from immature to adult age under gonadectomized (GDX) and sex steroids replaced conditions. Normal Wistar male and female rats from immature to adult age (day 21, 30, 45, 60 and 160 post-partum (pp)) were used in the present study. One group (I) of rats was GDX at an early age (day 10 pp) and the other group (II) at the adult age (day 120 pp). Group I rats were sacrificed at different experimental periods such as 21, 30, 45 and 60 days pp, and group II rats were sacrificed at day 160 pp. Another group of GDX rats from group I and II were replaced with physiological doses of testosterone or estradiol. Serum and thyroidal concentrations of sex steroids were estimated by RIA method and the concentrations of receptors by radioreceptor assay. Gonadectomy significantly decreased serum and thyroidal testosterone and estradiol and concentrations of androgen receptor (AR) and estrogen receptor (ER) in the thyroid. Replacement of sex steroids to GDX rats restored the normal level of sex steroids, AR and ER. Therefore, it is suggested from the present study that (i). sex steroids up-regulate their own receptors in the thyroid, (ii). sex steroids may influence thyroid growth and the proliferation of thyrocytes by modulating their receptor concentrations in the thyroid.
甲状腺是性类固醇的非经典靶器官之一。哺乳动物的肿瘤性和非肿瘤性甲状腺中存在雄激素和雌激素受体，这一点已有充分的文献记载。本研究的目的是阐明在去势（GDX）和性类固醇替代条件下，从幼年到成年的大鼠甲状腺中血清和甲状腺性类固醇及其受体的变化。本研究使用了从幼年到成年（产后第21、30、45、60和160天）的正常Wistar雄性和雌性大鼠。一组（I）大鼠在幼年（产后第10天）去势，另一组（II）在成年期（产后第120天）去势。I组大鼠在产后不同实验时期如21、30、45和60天处死，II组大鼠在产后160天处死。I组和II组的另一组去势大鼠用生理剂量的睾酮或雌二醇替代。用放射免疫分析法（RIA）测定血清和甲状腺性类固醇浓度，用放射受体分析法测定受体浓度。去势显著降低了血清和甲状腺睾酮、雌二醇以及甲状腺中雄激素受体（AR）和雌激素受体（ER）的浓度。给去势大鼠补充性类固醇可恢复性类固醇、AR和ER的正常水平。因此，本研究表明：（i）. 性类固醇上调其在甲状腺中的自身受体；（ii）. 性类固醇可能通过调节其在甲状腺中的受体浓度来影响甲状腺生长和甲状腺细胞的增殖。
