Blind hamsters had no alteration of the dialyzable fraction of serum thyroxine (T4) but had depressed total and free T4 concentrations compared to controls. Prevention of the effects of blinding by pinealectomy indicates pineal influence on circulating free T4 concentration. Parallel changes in free T4 and the free T4 index indicate adequacy of the index in representing pineal-induced changes i...

Several investigations have reported an increase, in stored serum, in apparent thyroxine (T4) concentration measured by competitive binding radioassay (CPBR) with thyroxine-binding globulin (TBG) as the binding reagent [l-7]. Watson and Lees [4] attributed this increase to the production of a “mimic T4” during storage. Recently, we [6] and Rootwelt [7], working independently, discovered that th...

Changes in plasma thyroxine (T4), triiodothyronine (T3), free thyroxine index (FT4I) and thyroid stimulating hormone were studied in 100 patients with Graves' disease treated with carbimazole. During therapy plasma T3 concentrations were disproportionately high compared to those of T4, the T4 : T3 ratio was low, and many patients were clinically euthyroid with a normal plasma T3 but low T4 conc...

To further evaluate thyroid function in patients with liver disease, we have measured total and free T3 and T4, thyroxine binding globulin, basal and thyrotropin releasing hormone-stimulated thyrotropin and thyroglobulin antibodies in 33 patients with liver cirrhosis, in 22 with chronic hepatitis and in 30 healthy controls. All the patients but one were clinically euthyroid. T3, FT3, T3/thyroxi...

Four cows received thyroxine injections (T4; 20 mg/d) and three cows received growth hormone injections (GH, 44 mg/d) for 4 d during successive 16-d experimental periods. Milk fat, lactose output, mammary uptake of glucose, oxygen and milk fat precursors were determined with each treatment. Injection of T4 increased lactose yield by 25% and fat yield 42%. The injection of GH increased fat and l...

10 normal young men received repository epinephrine repeatedly for 4 days during the course of a radiothyroxine (radio-T4) disappearance curve. During epinephrine administration, serum radio-T4 disappearance rate (k) slowed abruptly, fecal clearance decreased, urinary clearance was initially unchanged but later decreased slightly, volume of thyroxine distribution decreased, and external radioac...

Several indices of thyroid function were assessed in 74 patients with chronic renal failure. Sixty patients had undergone haemodialysis for varying periods. Within the first six months of haemodialysis treatment protein-bound iodine and total thyroxine (T4) levels rose, but after this T4 levels and the free thyroxine index fell progressively. Three out of the 12 patients who had undergone haemo...

The concentration of thyroxine-binding globulin (TBG) in the serum can now be measured by direct assays that are simple and inexpensive. Comparison of a direct measurement of TBG concentration with a widely used indirect method (Thyopac-3) showed that the indirect method was inaccurate when TBG concentrations were high. This will result in an increase in the derived free thyroxine index (FTI), ...

Thyroid gland is an essential endocrine that present in the human body. This review highlights production, regulation and disease conditions of thyroid hormones. The controlled with help hypothalamus pituitary brain. production hormones involves five main steps such synthesis thyroglobulin (TG), iodide uptake, iodination thyroglobulin, storage release. two important produced by are Thyroxine (T...

Thyroid hormone has been shown to stimulate bone resorption. Both endogenous hyperthyroidism and exogenous thyroxine suppressive therapy have been associated with reduction in bone mineral density (BMD), but the patholophysiology of thyroxine-induced bone loss is not well understood. First we studied the effect of L-T4 (0.1-0.3 microgram/g body weight ip/day) on bone turnover in rats by measuri...