Review Article New Approaches to Thyroid Hormones and Purinergic Signaling

Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. It is known that thyroid hormones influence a wide variety of events at the molecular, cellular, and functional levels. Thyroid hormones (TH) play pivotal roles in growth, cell proliferation, differentiation, apoptosis, development, and metabolic homeostasis via thyroid hormone receptors (TRs) by controlling the expression of TR target genes.Most of these effects result in pathological and physiological events and are alreadywell described in the literature. Even so,many recent studies have been devoted to bringing new information on problems in controlling the synthesis and release of these hormones and to elucidating mechanisms of the action of these hormones unconventionally. The purinergic system was recently linked to thyroid diseases, including enzymes, receptors, and enzyme products related to neurotransmitter release, nociception, behavior, and other vascular systems.Thus, throughout this text we intend to relate the relationship between the TH in physiological and pathological situations with the purinergic signaling. 1. An Overview about Thyroid Hormones Thyroxine (T4), triiodothyronine (T3), and reverse triiodo-thyronine (rT3) are the three main forms of thyroid hor-mones (TH) found in the bloodstream. T4 and T3 are essen-tial for normal functioning of different systems. TH pla