Triiodothyronine tagged with 131Ihas been used as a label for Walker 256 tumor cells. This hormone attaches rapidly to the surface of tumor cells, and after 60 min less than 5% of the radio activity was removed by each washing. Radioactive iodine administered as triiodothyronine remained in the hormone during experiments several hr in duration. A considerable portion of the hormone penetrated i...

Radioactive triiodothyronine reaching the rat brain after intravenous administration is rapidly and selectively taken up in the nerve ending fraction. A concentration gradient of radioactivity from brain cytosol to synaptosomes is observed at 5 min, increases linearly over the first hour, and is maintained for at least 10 hr. Radioactivity in the synaptosomes is due to triiodothyronine (90%) pl...

To determine whether intracerebrally localized iodothyronines produce thyroid hormone-related functional effects, heart rate responses were compared in conscious hypothyroid rats given triiodothyronine (T3) by either the intrathecal or the intravenous route. A significant increase in heart rate occurred within 18 h after 1.5 amol T3/100 g body wt was delivered intrathecally through a cannula pr...

The objective of study was to determine seasonal changes of leptin, triiodothyronine, and thyroxine and to determine whether an effect of thyroid hormones on leptin levels in Arabian mare. Blood samples were collected via jugular venipuncture from 16 Arabian mares during breeding and non-breeding season. Hormone concentrations were measured by radioimmunoassay. Mean concentrations of leptin wer...

Thyroxine is bound to a serum protein which appears in the electrophoretogram just ahead of alpha-2 globulin (1-4). Triiodothyronine also associates with this thyroxine binding globulin (T.B.G.) but can be displaced readily with thyroxine -while triiodothyronine will not readily displace thyroxine. Deiss, Albright, and Larson (5) suggested that the firm binding of thyroxine to T.B.G. might acco...

1. Surgical thyroidectomy decreased specific [3H]-ouabain binding to heart ventricular microsomes by 43% and gastrocnemius muscle microsomes by 34%. Administration of triiodothyronine to euthyroid rats enhanced specific [3H]-ouabain binding to heart and skeletal muscle membrane by 60% and 33% respectively. 2. Treatment of thyroidectomized rats with triiodothyronine increased specific [3H]-ouaba...

Measurement of serum triiodothyronine concentration is generally regarded as a valuable tool in the diagnosis of thyroid dysfunction. This importance has provided the impetus for the significant improvement in assay methodology that has occurred in the last two decades. The advent of monospecific antiserum and the discovery of blocking agents to the T3 binding serum proteins has enabled the dev...

Cardiovascular autonomic function was assessed in 9 subjects with Raynaud's phenomenon. The underlying diseases were systemic lupus erythematosus (n = 5), systemic sclerosis (n = 3) and rheumatoid arthritis (n = 1). Five standard non-invasive tests, 3 of heart rate and 2 of blood pressure, were employed. Compared with age and sex matched controls (n = 25), the number of values abnormal was 24 o...

Thyroxine is bound to a serum protein which appears in the electrophoretogram just ahead of alpha-2 globulin (1-4). Triiodothyronine also associates with this thyroxine binding globulin (T.B.G.) but can be displaced readily with thyroxine -while triiodothyronine will not readily displace thyroxine. Deiss, Albright, and Larson (5) suggested that the firm binding of thyroxine to T.B.G. might acco...

OBJECTIVE To study the effect of different doses of triiodothyronine on gene expression of the adipokines leptin and adiponectin, at different times, and to evaluate the difference in expression between the two adipokines in each group. METHODS 3T3-L1 adipocytes were incubated with triiodothyronine at physiological dose (10nM) and supraphysiological doses (100nM or 1,000nM), or without triiod...