Tumor Necrosis Factor-α가 돼지 간 및 신장의 절편 및 추출액에서 T₄로 부터 T₃로의 말초전환에 미치는 영향

Abstract

Abnormal thyroid function is seen in a wide variety of patients with acute and chronic nonthyroidal-illness, consisting of reduction in both thyroid function and peripheral T₄ T₃ conversion including dercreased serum thyroxin(T₄), decreased triiodothyonine and normal or slightly increased serum TSH. Recently increasing awareness of the role of tumor necrosis factor-α(TNF-α) in systemic illness led us to consider a possible contribution of TNF-α to thyroid dysfunction in this setting. So we hypothesized that TNF-α might affect peripheral conversion of T₄ to T₃. We, therefore, explored the effects of TNF-α in slices and extracts of porcine liver and kidney. Thyroxine(T₄, 5㎍/㎖) was incubated in 0.15M phosphate buffer(PH 7.4) with slices(approximately 0.3 g-equivalent of tissue) and extracts (approximately 0.23 g-equivalent of tissue) of porcine liver and kidney with various concentrations(0~500pg/ml) of recombinant human TNF-α for 2 hours at 37˚C, and the T₃ generated during incubation was measured by radioimmunoassay of an ethanol extracts of the extracts and the homogenates of the slices. The slices produced more T₃ than extracts and the kidney was more active than the liver. TNF-α inhibited T₄ to T₃ conversion in does-dependent manner in slices and extracts of porcine liver and kidney. Our data suggest that TNF-α have inhibitory effect of T₄ to T₃ conversion in liver and kidney