Results of thyroid function tests were analysed in 199 clinically euthyroid inpatients with normal serum thyroid stimulating hormone values. Serum total triiodothyronine was less than 1.25 nmol/l in 61.8% of samples, free triiodothyronine less than 3.9 pmol/l in 57.8%, total thyroxine less than 63 nmol/l in 21.1% and free thyroxine less than 9.5 pmol/l in 17.6%. In contrast, thyroxine binding g...

Effects of pH, feeding regime and thyroxine on growth survival Parosphromenus tweediei (Kottelat Ng, 2005) fry

In the past, investigators have used thyroxine labeled either with JIP" in the 3',5'-position or with C14 in the carboxyl position to study the metabolism of thyroxine in vivo. Although these studies have yielded much valuable information, our knowledge about the metabolic fate of the ring structure in thyroxine is incomplete because both the 3'5'-IJ13 and the carboxyl-C14 are rapidly removed f...

This paper describes a rapid and accurate method for determining binding abilities of thyroid hormones to their corresponding serum proteins: prealbumin, albumin and thyroxine binding globulin. A tube cell agarose gel electrophoresis is used with radioactive labelled triiodothyronine or thyroxine. The distribution curve shows characteristic peaks for prealbumin, albumin and thyroxine binding gl...

THE measurement of serum free thyroxine (FT4), which forms a small fraction (0.01-0.05 per cent) of the circulating total thyroxine (TT4), might be expected to provide the most accurate single biochemical index of thyroid status, on the basis that only free hormone is bioavailable. The conventional estimation of FT4 by equilibrium dialysis' is time consuming and the arrival of radioimmunoassay ...

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...

Rana catesbeiana tadpoles were injected with [(14)C]thyroxine, and the subcellular distribution of the labeled hormone was determined. At 25 degrees the amount of isotope found in the liver was maximal after 1-2 hr and then rapidly decreased to a relatively constant value. A large percentage of the hormone was found associated with the purified nuclei isolated 24 hr after injection of [(14)C]th...

Considerable evidence suggests that the concentration of free thyroxine, circulating unbound to serum proteins, is more closely relattd to a subject's thyroidal status than is the concentration of total thyroxine (1). Because of the intense binding of thyroxine by the serum proteins, the concentration of free thyroxine is very small and not measurable by conventional chemical methods. Robbins a...

Thyroid hormone state was assessed in a group of postmenopausal women who had received long term treatment with oestrogen. Serum concentrations of total thyroxine, triiodothyronine, and thyroxine binding globulin were raised compared with those in a control group given placebo; serum concentrations of thyroid stimulating hormone did not differ between the groups. Oestrogen treatment resulted in...