what about this? I assume that this is what harmoniccharge is referencing in her post below:
another unpleasant side effect is liver (and kidney) damage as evidenced by liver enzymes getting into the blood from injured liver tissue, the liver damage also deprecates deiodination of T4 so TSH rises (TSH is governed by both T4 and T3 levels)
"most of the T3 produced each day is formed by the extrathyroidal 5'-deiodination (outer ring deiodination) of T4 . this reaction is catalysed by T4-deiodinase. the liver and kidney have the highest T4-deiodinating activity per unit tissue, and probably the source of much of the T3 in serum. however deiodinating activity is widely distributed, and it is likely multiple tissues contribute to overall extrathyroidal t3 production."
the above paragraph p265 from 'endocrinology and metabolism' by frelig and frohman, google books