Crystalline trypsinogen is completely transformed into trypsin by means of trypsin in the presence of calcium salts. The process follows the course of a pure autocatalytic unimolecular reaction. In the absence of calcium salts, the autocatalytic formation of trypsin from trypsinogen is complicated by the transformation of part of the trypsinogen into an inert protein which cannot be changed int...

Thyroid hormones are essential for normal development and metabolism. Thyroid hormone biosynthesis requires iodide uptake into the thyrocytes and efflux into the follicular lumen, where it is organified on selected tyrosyls of thyroglobulin. Uptake of iodide into the thyrocytes is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter (NIS), which actively cotransports two ...

Recent studies have shown that the calcium channel blockers, when combined with standard anticancer drugs, help overcome resistance that often develops to those drugs. Little is known about the effects of the calcium channel blockers themselves on tumor cells. We have studied the effects of one calcium channel blocker, vcrapamil, on human tumor cell lines in vitro. Our results show a reversible...

Recent studies have shown that the calcium channel blockers, when combined with standard anticancer drugs, help overcome resistance that often develops to those drugs. Little is known about the effects of the calcium channel blockers themselves on tumor cells. We have studied the effects of one calcium channel blocker, verapamil, on human tumor cell lines in vitro. Our results show a reversible...

The regulation of thyroid metabolism by iodide involves numerous inhibitory effects. However, in unstimulated dog thyroid slices, a small inconstant stimulatory effect of iodide on H(2)O(2) generation is observed. The only other stimulatory effect reported with iodide is on [1-(14)C]glucose oxidation, i.e., on the pentose phosphate pathway. Because we have recently demonstrated that the pentose...

In a preceding report, we showed evidence that thyrotropin (TSH) stimulates Ca2+ efflux from mouse thyroid gland and that TSH stimulation of Ca2+ efflux is inhibited by acute administration of excess iodide to mice fed a low iodine diet (Hashizume et al., 1984). The observations suggested that iodide inhibits Ca2+ efflux through an inhibition of TSH-sensitive adenylate cyclase activity. We foun...

sodium iodide-131 is administrated for treatment of hyperthyroidism and thyroid cancer. iodine-131 has multiple routs of excretion (urine, saliva, sweat, milk, feces, exhalation) from the body. patients receiving sodium iodide-131 therapy exposes other persons and the environment to unwanted radiation and contamination. the major source of radiation dose from administration of iodine-131 is ext...

The potassium salt of an extremely bulky β-diketiminate, [K(Ar*Nacnac)] (Ar*Nacnac, [(Ar*NCMe)2CH]−; Ar*, C6H2Me{C(H)Ph2}2-4,2,6) was reacted with either CaI2 or YbI2(THF)2, which afforded [(Ar*Nacnac)MI] (M = Ca Yb). These are the first examples structurally characterised, donor solvent-free, N-arene substituted β-diketiminato calcium and ytterbium complexes that incorporate a terminal iodide ...

Several apical iodide translocation pathways have been proposed for iodide efflux out of thyroid follicular cells, including a pathway mediated by the sodium-coupled monocarboxylate transporter 1 (SMCT1), which remains controversial. Herein, we evaluate structural and functional similarities between SMCT1 and the well-studied sodium-iodide symporter (NIS) that mediates the first step of iodide ...