Azizi F
Am J Physiol. 1979 Sep;237(3):E224-6. doi: 10.1152/ajpendo.1979.237.3.E224.
As the age of young adult male rats increased from 30 to 150 days, the serum thyroxine (T4) decreased by 50% and the serum thyroid-stimulating hormone (TSH) increased by 250%. There was no change in the serum triiodothyronine (T3). The increment in serum TSH after injection of thyrotropin-releasing hormone (TRH) was not significantly different at any of the ages studied, but the old animals had significantly lower increments in serum T4 and T3 after subcutaneous administration of bovine TSH. Despite a higher basal serum TSH, the older rats had a lesser increase in serum TSH after thyroidectomy or propylthiouracil. Thus, 1) there is a progressive decline in intrinsic thyroid function between 30 and 150 days of age in male rats, and 2) pituitary TSH response to fall in serum concentration of thyroid hormones is also decreased with age.
随着年轻成年雄性大鼠的年龄从30天增加到150天，血清甲状腺素（T4）下降了50%，血清促甲状腺激素（TSH）增加了250%。血清三碘甲状腺原氨酸（T3）没有变化。在研究的任何年龄，注射促甲状腺激素释放激素（TRH）后血清TSH的增量没有显著差异，但老年动物皮下注射牛TSH后血清T4和T3的增量显著较低。尽管基础血清TSH较高，但老年大鼠甲状腺切除或给予丙硫氧嘧啶后血清TSH的增加较少。因此，1）雄性大鼠在30至150日龄之间甲状腺内在功能逐渐下降，2）垂体TSH对血清甲状腺激素浓度下降的反应也随年龄降低。
