This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schmidt, B. M. W. Articles by Wehling, M. Search for Related Content PubMed PubMed Citation Articles by Schmidt, B. M. W. Articles by Wehling, M.

Nongenomic Cardiovascular Effects of Triiodothyronine in Euthyroid Male Volunteers

Institute of Clinical Pharmacology, University Hospital of Mannheim, Faculty for Clinical Medicine Mannheim, University of Heidelberg (B.M.W.S., N.M., A.C.G., H.-C.T., M.F., M.C., M.W.), 68135 Mannheim, Germany; and Medical Department 4/Nephrology, University of Erlangen-Nürnberg (B.M.W.S.), 90471 Nürnberg, Germany

Address all correspondence and requests for reprints to: Martin Wehling, M.D., Institute of Clinical Pharmacology, Faculty of Clinical Medicine, Ruprecht Karls University of Heidelberg, Theodor Kutzer Ufer 1-3, 68167 Mannheim, Germany. E-mail: . martin.wehling{at}kpha.ma.uni-heidelberg.de

Abstract

T₃ has been shown to exert cardiovascular effects. These effects have not yet been defined with regard to the mode of action (nongenomic vs. genomic) and with regard to an interaction with the adrenergic system in humans. To address these issues we conducted a randomized, double blind, 6-fold cross-over trial in 18 healthy male volunteers. After pretreatment with the ß-agonist dobutamine, the ß-blocking agent esmolol, or placebo (0.9% NaCl), 100 µg T₃ or placebo were injected. Primary target variables were systemic vascular resistance (SVR) and cardiac output (CO) within 45 min after injection of T₃ vs. placebo after placebo pretreatment. Sympatho-vagal balance was assessed by measurement of heart rate variability.

T₃ caused a lower SVR and a higher CO than placebo (P < 0.001) after pretreatment with placebo. An increased low frequency (LF)/high frequency (HF) ratio (power in LF/power in HF band) after T₃ compared with placebo (P = 0.004) suggests an increase in sympathetic tone. After pretreatment with dobutamine, the effects of T₃ on SVR and CO were abolished, and the effect on LF/HF ratio was reversed. After pretreatment with esmolol, the effects on SVR and LF/HF ratio were reversed. Our data show, for the first time, nongenomic cardiovascular effects of T₃ in humans.

This article has been cited by other articles:

				R. Napoli, V. Guardasole, V. Angelini, E. Zarra, D. Terracciano, C. D'Anna, M. Matarazzo, U. Oliviero, V. Macchia, and L. Sacca Acute Effects of Triiodothyronine on Endothelial Function in Human Subjects J. Clin. Endocrinol. Metab., January 1, 2007; 92(1): 250 - 254. [Abstract] [Full Text] [PDF]

				Y. Hiroi, H.-H. Kim, H. Ying, F. Furuya, Z. Huang, T. Simoncini, K. Noma, K. Ueki, N.-H. Nguyen, T. S. Scanlan, et al. Rapid nongenomic actions of thyroid hormone PNAS, September 19, 2006; 103(38): 14104 - 14109. [Abstract] [Full Text] [PDF]

				A. M. Ranasinghe, D. W. Quinn, D. Pagano, N. Edwards, M. Faroqui, T. R. Graham, B. E. Keogh, J. Mascaro, D. W. Riddington, S. J. Rooney, et al. Glucose-Insulin-Potassium and Tri-Iodothyronine Individually Improve Hemodynamic Performance and Are Associated With Reduced Troponin I Release After On-Pump Coronary Artery Bypass Grafting Circulation, July 4, 2006; 114(1_suppl): I-245 - I-250. [Abstract] [Full Text] [PDF]

				M. C. Farach-Carson and P. J. Davis Steroid Hormone Interactions with Target Cells: Cross Talk between Membrane and Nuclear Pathways J. Pharmacol. Exp. Ther., December 1, 2003; 307(3): 839 - 845. [Abstract] [Full Text] [PDF]