[Thyroid hormone analogs: an important biological supply and new therapeutic possibilities].

Thyroid hormones [predominantly 3, 5, 3 -I- iodothyronine (T3)] regulate cholesterol and lipoprotein metabolism but cardiac effects restrict their use as hypolipidemic drugs. New molecules have been developped which target specifically the thyroid hormone receptor ss, predominant isoform in liver. The first thyroid hormone agonist, called GC1, has selective actions compared to T3. In animals, GC1 reduced serum cholesterol and serum triglycerides, probably by stimulation important steps in reverse cholesterol transport. Other selective thyromimetic, KB- 2115 and KB - 141 have similar effects. Another class of thyroid hormone analogs, the thyronamines have emerged recently but the basic biology of this new class of endogenous thyroid hormone remains to better understood. Therefore, these molecules may be a potentially treatment for obesity and reduction cholesterol, triglycerides and lipoprotein (a). To date the studies in human are preliminary. Tolerance and efficacy of these drugs are still under investigation.