Thyroid hormone homeostasis and the liver.
Thyroid hormone homeostasis and the liver.
复制标题
甲状腺激素稳态和肝脏。
DOI：
10.1055/s-2008-1041755
复制
发表时间：
1985
影响因子：
4.2
通讯作者：
Levey,GS
中科院分区：
文献类型：
--
作者：
Salata,R;Klein,I;Levey,GS
Thyroid hormone synthesis and secretion is regulated by a classic feedback loop system. The hypothalamus, through the release of thyrotropinreleasing hormone (TRH), stimulates production of thyroid-stimulating hormone (TSH) by the anterior pituitary. TSH in turn stimulates various parameters of thyroid gland function, increasing the rates of synthesis as well as the rates of release of both tetraiodothyronine (thyroxine, T4) and triiodothyronine (T3). This feedback loop system is then completed by the ability of T4 and T3 to inhibit the subsequent secretion of TSH and probably that of TRH (Fig. 1).Normal thyroid hormone synthesis requires a series of sequential steps that take place within the follicular cells of the thyroid gland. Ingested iodine is transported to the thyroid, trapped, organified, and incorporated into tyrosyl residues of thyroglobulin. These iodotyrosines are coupled to form either T3 or T4, which are stored in thyroglobulin in the follicular colloid.'Under normal conditions the stimulation of TSH causes some thyroglobulin to be transported back into the follicular cell in the form of colloid droplets. The droplets fuse with lysosomes and the thyroglobulin undergoes proteolysis with the liberation of T4 and T3. The free hormone generated by this process leaves the thyroid gland by diffusion into the extracellular space. Thyroid hormones circulate in blood attached primarily to three proteins that are synthesized in the liver: 2 thyroxine-binding globulin (TBG), thyroxine-
