title: Cardiac actions of thyroid hormone metabolites.
abstract: Thyroid hormones (THs) have a major role in regulating cardiac function. Their classical mechanism of action is genomic. Recent findings have broadened our knowledge about the (patho)physiology of cardiac regulation by THs, to include non-genomic actions of THs and their metabolites (THM). This review provides an overview of classical and non-classical cardiac effects controlled by: i) iodothyronines (thyroxine, T4; 3,5,3'-triiodothyronine,T3; 3, 5-diiodothyronine, T2); ii) thyronamines (thyronamine, T0AM; 3-iodothyronamine, T1AM); and iii) iodothyroacetic acids (3, 5, 3', 5'-tetraiodothyroacetic acid, tetrac; 3, 5, 3'-triiodothyroacetic acid, triac; 3-iodothyroacetic acid, TA1). Whereas iodothyronines enhance both diastolic and systolic function and heart rate, thyronamines were observed to have negative inotropic and chronotropic effects and might function as a brake with respect to THs, although their physiological role is unclear. Moreover, thyronamines showed a cardioprotective effect at physiological concentrations. The cardiac effects of iodothyroacetic acids seem to be limited and need to be elucidated.
authors.affiliation: Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy; National Research Council (CNR), Institute of Clinical Physiology (IFC), Via Giuseppe Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Rutigliano
authors.affiliation: Department of Pathology, University of Pisa, Via Roma 55, 56126 Pisa, Italy. Electronic address: riccardo.zucchi@med.unipi.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Zucchi
mesh_terms: D000818:Animals; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D013963:Thyroid Hormones / Q000378:metabolism*; D013970:Thyronines / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism
chemical_list: D013963:Thyroid Hormones; D013970:Thyronines; C004547:thyronamine; D013974:Thyroxine
keywords: 3, 5-Diiodothyronine; 3-Iodothyronamine; Cardioprotection; Non-genomic effects; Thyroacetic acids; Thyroid hormones