Objective To study the modulation of interleukin-6 (IL-6) generation from human thyroid cells.MethodsThyroid tissues were obtained at surgery from patients with Graves disease.IL-6 in the supernatant of cultured thyrocytes was detected with ultra-sensitive ELISA.mRNA was extracted respectively from primary human cultured thyroidal cells under stimulated and unstimulated conditions,and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used for produce high concentration IL-6.Thyrotropin (TSH,103mU/L),tumor necrosis factor-α(TNF-α,10-1 U/ml),interleukin-1(IL-1,10 U/ml) and adrenaline(10-5mol/L) significantly increased IL-6 levels in the supernatant of cultured thyroid cells,whereas dexamethasone (10 mmol/L) markedly suppressed IL-6 release from thyrocytes.NaI of 10-4 mol/L results,at a concentration of 10-103 mmol/L,dexamethasone could gradually suppress IL-6 gene expression on human thyrocytes,while TNF-α could obviously stimulate the production of IL-6 mRNA in the range of 10-1-102 U/ml.On the level of 102 U/ml,IL-1 increased the expression of IL-6,but the same effect could not be shown when IL-1 was 10-1 or 10 U/ml.Sodium iodine (NaI) could not affect IL-6 gene from the level of 10-8 to 10-4 mol/L.ConclusionIL-6 produced by thyrocytes might be regulated by many factors that modulate thyroid functions in vitro as well as in vivo.``