There is an interesting article by P. Reed Larson and others on the deiodinases which is open access. They are considering manipulating the deiodinases as a therapeutic model. I think it will be a long time before science has enough understanding of the system that this could be done without damaging the patient. PR
"Deiodinases control TH action in a precise spatio-temporal fashion thereby providing a novel mechanism for the local paracrine and autocrine regulation of TH action. This remarkable tissue-specific regulation of intracellular thyroid status remains hidden due to the maintenance of constant circulating TH concentrations by the hypothalamic–pituitary–thyroid axis."