For the purpose of biochemical studies utilizing radioiodine 1131 as a tracer material, it is desirable to have a simple, sensitive, and thoroughly validated method for the measurement of the radioactivity of the biological samples. The present investigation was undertaken to provide such a method, with part,icular reference to the thyroid of the rat, but is adaptable with appropriate modificat...

Erythrocytes are hemolyzed by myeloperoxidase, an H2O2-generating system (glucose + glucose oxidase; hypoxanthine + xanthine oxidase) and an oxidizable cofactor (chloride, iodide, thyroxine, triiodothyronine). The combined effect of chloride and either iodide or the thyroid hormones is greater than additive. Myeloperoxidase can be replaced by lactoperoxidase in the iodide-, thyroxine and triiod...

T3 or iodide, at the concentration of 10- minus 3M, inhibits TSH- or dibutyryl-cyclic AMP-induced thyroidal intracellular colloid droplet formation, while leaving the TSH-induced increase in cyclic AMP levels intact. The effect of T3 appeared not to be mediated through the iodide derived from deiodination of T3. Those results clearly demonstrate that T3 or iodide acts at the point beyond cyclic...

During the development of a new method of analyzing crystals by X-rays we discovered that the X-rays characteristic of and excited in the chemical elements in a crystal are reflected by the crystal itself. The reflection takes place both in accordance with the Bragg law: nX = 24 sin 0 and. also in an anomalous fashion. The ionization spectrometer utilized in these investigations and the various...

It is hypothesized that dietary iodine deficiency is associated with the development of mammary pathology and cancer. A review of the literature on this correlation and of the author's own work on the antioxidant function of iodide in iodide-concentrating extrathyroidal cells is reported. Mammary gland is embryogenetically derived from primitive iodide-concentrating ectoderm, and alveolar and d...