[The effect of glucose and 2-deoxy-D-glucose on the monodeiodination of thyroxine by human skin fibroblasts in culture (author's transl)].

The effect of glucose and 2-deoxy-D-glucose on the extrathyroidal monodeiodination of thyroxine (T4) to 3, 5, 3'-triiodothyronine (T3) and 3, 3', 5'-triiodohyronine (reverse T3;rT3) was studied in human skin fibroblasts in culture. When the fibroblasts were maintained in glucose-free Eagle's MEM fortified with 3% fetal calf serum, intracellular T4 was unchanged, intracellular T3 decreased, and intracellular rT3 markedly increased as compared with those in Eagle's MEM containing 3% fetal calf serum and 100 mg/dl glucose. In this study, the ratio of T3 to T4 fell, and the ratio of rT3 to T4 and rT3 to T3 rose remarkably in fibroblasts in glucose-deprived media. When the fibroblasts were maintained in Eagle's MEM containing 3% fetal calf serum and various concentration of 2-deoxy-D-glucose, intracellular concentrations of thyroid hormone were decreased as compared with those in 2-deoxy-D-glucose-free control medium. The ratio of rT3 to T4 and rT3 to T3, however, augmented although the ratio of T3 to T4 did not change in fibroblasts in the media with 2-deoxy-D-glucose. Cellular energetic deprivation derived from the glucose-free medium and the medium containing 2-deoxy-D-glucose influenced the extrathyroidal monodeiodination of T4 by shifting from T3 to rT3 or vice versa, in addition to the feedback system of the pituitary-thyroidal exis.