3,3′-Diiodothyronine Production, a Major Pathway of Peripheral Iodothyronine Metabolism in Man

Serum concentrations of 3,3'-diiodothyronine, 3',5'-diiodothyronine, and 3,5-diiodothyronine in altered thyroid states.

“…Previous studies (Wu et al, 1976;Burman et al, 1977;Burger et al, 1977;Gavin et al, 1978;Burman et al, 1978;Chopra et al, 1978;Faber et al, 1979) have demonstrated that serum T4, T3, rT3, 3,3' -T2 and 3' ,5'-T2 in hyperthyroidism, while they are diminished in hypothyroidism. The present study confirmed these previous observations and further demonstrated that serum 3,3'-T2 and 3',5'-T2 concentrations changed parallel with T4, T3 and rT3 concentrations to the norml ranges in hyperthyroid patients during the methimazole treatment and in hypothyroid patients during the T4 replacement therapy.…”

Metabolism of 3,3'-diiodothyronine and 3'-monoiodothyronine, and effect of potassium cyanide and dinitrophenol on glucuronidation of thyroxine in cultured rat hepatoma cells.

“…Therefore, the formation of 3, 3'-T2 is involved in the metabolism of the thyroid hormones in vivo. However, the serum level of 3, 3'-T2 was extremely low (Wu et al, 1976;Burman et al, 1977;Burger and Sakoloff, 1978;Gavin et al, 1978). Judging from these data, even if a large amount of 3, 3'-T2 is produced by monodeiodinations of T3 or rT3, this matabolite is Immediately converted to its conjugates.…”

“…In fact, 3, 3'-T2 was detected in the rat kidney after injection of the thyroid hormones (Roche et al, 1956;Roche et al, 1959) and in serum (Wu et al, 1976;Burman et al, 1977;Burgar and Sakoloff, 1977;Gavin et al, 1978). Furthermore, 3, 3' -T2 conjugates were identified in bile, urine or plasma (Flock et al, 1960;1963).…”

Comprehensive Kinetics of Triiodothyronine Production, Distribution, and Metabolism in Blood and Tissue Pools of the Rat Using Optimized Blood-Sampling Protocols*

“…The columns were eluted first with 20 mM sodium phosphate buffer, pH 7.4 (i.e. PB), containing 3.8 g/liter Na 2 S2O 5 (final pH, 6.5) to minimize any possible in vitro deiodination (12,21). 125 ILabeled iodoprotein and 125 I-labeled iodide eluted in the first 5 ml, as shown in the first double peak of the heavy curve in Fig.…”