Figure 1.

Avenues for regulation of lipid metabolism by thyroid hormones and analogs. THs may act through transcriptional regulation by nuclear TR binding but also through interactions involving cytosolic/mitochondrial TRs or other proteins, each of which influencing lipid metabolism. For clarity, the TH analogs have not been depicted separately, negative effects on insulin sensitivity have only been demonstrated for a subset (see text). Of the thyroid hormone metabolites only T2 is depicted, since T2 is the only TH metabolite thus far with low affinity for TRα and positive effects on metabolism. Avenues are depicted as blue arrows. Dotted arrows: yet to be determined/confirmed. Effects are depicted as red arrows (negative) or green arrows (positive).