肿瘤坏死因子对人甲状腺细胞分泌功能的影响

EFFECT OF TUMOR NECROSls FACTOR ON THE SECRETIONFUNCTlON OF HUMAN CULTURED THYROID CELLS

将正常人甲状腺组织行单层细胞培养后分为两组，Ａ组内加入定量ｂＴｓＨ（１ｍＵ／Ｌ）和不同浓度肿瘤坏死因子（ＴＮＦ），Ｂ组内仅加ＴＮＦ。培养２４和４８小时，分别测定上清液甲状腺球蛋白（ＴＧ）含量。结果：Ａ组ＴＧ含量随ＴＮＦ浓度增加而明显减少，提示ＴＮＦ可阻断ＴＳＨ对甲状腺细胞的刺激作用；Ｂ组ＴＧ含量则不受ＴＮＦ影响，说明ＴＮＦ对甲状腺细胞无直接杀伤作用。正常甲状腺功能的病态综合征（亦称：低Ｔ＿３综合征）患者血ＴＮＦ浓度明显升高，可能是导致Ｔ＿３和Ｔ＿４降低的原因之一。

It is the increased blood levels of tumor necrosis factor (TNF) that are found in systemic nonthyroid diseases which are char-racterized by reduction in setum T-3, T-4 and increase in serum rT-3 (the sick euthyroid syndrome ). The serum levels of TNF correlatewith the severity and prognosis of the diseases. The more the levels of TNF increase,the higher the mortality of the illness. Thisphenornenon suggested that the TNF might affect the thyroid function.We therefore , investigated the effect of TNF on TSH stimulation of the thyroid gland,employing human cultured thyroid cells.Cultuted human thyroid cells in monolayer were divided into 2 groups : group A was incubated with bTSH (I mU/L) and increasingconcentrations of recombinant TNF (from 0 to 1000ng/L); group B incubated only with increasing concentrations of TNF (from 0to 1000 ng/L). At the end of 24h and 48h incubation,the thyroglobulin (TG) levels of supernatant were measured with ELISA re-spectively. The results showed that in group A the levels of TG apparently decreased with the increasing concentrations of TNF,suggesting TNF could block the effect of TSH stimulation of thyroid cells in group B there were no apparent changes in the levelsof TG,suggesting TNF did not directly depress the thyroid cell function. From this result,we hypothesized that increase of serumTNF may be responsible for the thyroid hypofunction in patients with sick euthyroid syndrome.