Figure 3. A and B, Deiodination of T₃ and TA3 by recombinant human D3.

Dilutions of lysates of COS1 cells transfected with human D3 were incubated for 60 minutes at 37°C with [¹²⁵I]T₃ (A) or [¹²⁵I]TA3 (B). C and D, Conversion of T₃ and TA3 by endogenous D3 in intact SH-SY5Y cells. Cells were incubated for 4 or 24 hours at 37°C with [¹²⁵I]T₃ (C) or [¹²⁵I]TA3 (D). Results are presented as mean ± SEM (n = 2–3).