Edwin C. Albright

In vitro conversion of thyroxin to triiodothyronine by kidney slices.

Summary and Conclusions 1. Chromatographically pure I131 labelled 1-thyroxin was added to surviving kidney slices which were incubated in a modified Krebs-Ringer phosphate solution. 2. Following incubation, the slices were homogenized, extracted with butanol and the thyroxin and triiodothyronine separated and identified by paper chromatography. 3. The triiodothyronine was found to be radioactive. This was taken as evidence of deiodination of thyroxin to triiodothyronine. 4. Conversion of thyroxin to triiodothyronine was reduced by excess iodide and abolished by boiling the tissue or by the addition of potassium cyanide to the media.

Thyroxine binding capacity of serum alpha globulin in hypothyroid, euthyroid, and hyperthyroid subjects.

Circulating thyroxine is associated with a specific serum alpha globulin ( 1-6). This thyroxinebinding globulin (TBG) appears to exist in plasma in quantity greater than is required to bind endogenous thyroxine, for it will bind additional thyroxine when added in vitro (6-8). This capacity of TBGto bind exogenous thyroxine in vitro appeared in prelinary studies (9) to depend upon the state of thyroid gland activity. The purpose of this paper is to report in more detail the capacity of the serum of hypothyroid, euthyroid, and hyperthyroid subjects to bind added thyroxine.

Alteration in tissue and serum concentrations of TSH, iodide, T4 and T3 induced by various dietary iodide levels.

Summary Isotopic equilibrium and radioimmunoassay methods were used to evaluate the effects of increases in iodide intake on tissue and serum concentrations of thyroid hormones. Within the range of iodide levels used total iodine in peripheral tissues and serum increase directly with iodide intake but this change is mainly due to an increase in inorganic iodide. It is concluded that increases in tissue thyroid hormone concentrations occur within a relatively narrow range of iodide intake and maximal concentration occurs at an iodide intake of 3-10 μg/day.

Single Dimension Chromatographic Separation of Thyroxin and Triiodothyronine.

Summary A method is described by which iodine-containing amino acids, including thyroxin and triiodothyronine can be adequately separated by single dimension chromatography. Physiological quantities of labelled thyroxin and triiodothyronine have been added to serum, extracted with butanol and separated by this method.

Relationship of the P: Ratio to Thyroid Hormone Content of Isolated Rat Liver Mitochondria

Summary An isotope equilibrium technique was used to measure mitochondrial thyroid hormone concentration in thyroidectomized, partially thyroidectomized, and intact rats in order to correlate this with the P:O ratios in the mitochondria from these animals. The data suggest that thyroidectomized rats have P:O ratios higher than normal rats. Furthermore, there appears to be an inverse linear relationship between mitochondrial thyroid hormone content and the P:O ratio.

Thyroxin analogs and their place in therapy.

Recent discovery of several naturally occurring thyroxin analogs has led to the study of a number of synthetic compounds having thyromimetic activity. The place of these thyroxin analogs in therapy is described in relation to replacement therapy for hypothyroidism (use of L-triiodothyronine compared with desiccated thyroid and L-thyroxin) and to treatment of hypercholesteremia (experimental results with D-thyroxin, D-triiodothyronine, tetraiodothyroacetic and triiodothyroacetic acid, triiodothyropropionic acid, diiodothyroacetic acid and diiodothyroformic acid).