Effects of thyroxine on cardiac function and lymphocyte beta-adrenoceptors in patients with chronic congestive heart failure.
OBJECTIVE
To explore the effects of thyroid hormone (TH) on cardiac function and peripheral lymphocyte beta-adrenoceptors (beta-ARs) of patients with chronic congestive heart failure (CHF).


METHODS
Twenty-eight patients with class III or IV advanced CHF due to dilated cardiomyopathy (DCM) or ischemic cardiomyopathy (ICM) were randomly divided into groups A and B. L-thyroxine (L-T(50)) was administered to group B. Exercise tolerance, chest X-rays, and echocardiographic parameters were obtained before and after one month of treatment, Ficoll-hypaque solution was used to separate peripheral lymphocytes, and (125)I-pindolol radioligand binding was used to measure beta-AR levels in peripheral lymphocytes.


RESULTS
L-T(50) therapy improved cardiac output [CO, (2.98 +/- 0.31)L/min vs (3.24 +/- 0.28) L/min, P < 0.01], left ventricular ejection fraction (LVEF, 26.21% +/- 3.21% vs 37.93% +/- 9.01%, P < 0.01), and decreased isovolumetric relaxation time (IVRT, 0.12 +/- 0.04 vs 0.10 +/- 0.02, P < 0.01). Serum TH levels and the maximal number of beta-AR binding sites (beta(max)) in peripheral lymphocytes were lower in patients with CHF than in normal healthy people, but L-T(50) administration induced a beta-AR up-regulation on peripheral lymphocyte surfaces. L-T(50) was well tolerated without episodes of ischemia or arrhythmia. There was no significant change in heart rate or metabolic rate.


CONCLUSIONS
TH administration improves cardiac function and beta-AR expression in peripheral lymphocytes of patients with CHF.
Lu
Xinzheng
X
Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China. xzlu@sohu.com
Huang
Jun
J
Zhang
Xiaowen
X
Li
Xinhua
X
Wang
Chijing
C
Zhang
Peisheng
P
Chen
Yongsheng
Y
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002908:Chronic Disease; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D013974:Thyroxine / Q000494:pharmacology*
D011943:Receptors, Adrenergic, beta; D013974:Thyroxine