J Korean Soc Endocrinol.  1994 Sep;10(3):242-248.

The Effect of Tumor Necrosis Factor - α on Extra Thyroidal Conversion of T4 to T3 in Slices and Extracts of Porcine Liver and Kidney

• Jo JW
• Nam MS
• Nam SY
• Song YD
• Lim SK
• Lee HC
• Huh KB
• Kim KR
• Lee EJ

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 T_4 to T_3 conversion including decreased serum thyroxin(T_4), decreased triiodothyronine and normal or slightly increased serum TSH. Recently increasing awareness of the role tumor necrosis factor-alpha(TNF-alpha) in systemic illness led us to consider a possible contribution of TNF-alpha to thyroid dysfunction in this setting. So we hypothesized that TNF-alpha might affect peripheral conversion of T_4 to T_3. We, therefore, explored the effects of TNF-alpha in slices and extracts of porcine liver and kidney. Thyroxine(T_4, 5ug/ml) 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-alpha for 2 hours at 37 degree, and the T_3 generated during incubation was measured by radioimmunoassay of an ethanol extracts of the extracts and the homogenates of the slices. The slices produced more T_3 than extracts and the kidney was more active than the liver. TNF-alpha inhibited T_4 to T_3 conversion in dose-dependent manner in slices and extracts of porcine liver and kidney. Our data suggest that TNF-alpha have inhibitory effect of T_4 to T_3 conversion in liver and kidney(J Kor Soc Endocrinol 10: 242-248, 1995).

MeSH Terms

Ethanol
Humans
Kidney*
Liver*
Necrosis
Radioimmunoassay
Thyroid Gland*
Triiodothyronine
Tumor Necrosis Factor-alpha*
Ethanol
Triiodothyronine
Tumor Necrosis Factor-alpha