Iodine

About: Iodine is a research topic. Over the lifetime, 8936 publications have been published within this topic receiving 139981 citations. The topic is also known as: I & element 53.

Speciation of Iodine in High Iodine Groundwater in China Associated with Goitre and Hypothyroidism

Abstract: Iodine intake affects the occurrence of disease in a population. Excessive iodine intake may be caused by a high iodine content of drinking water. Tap water in few locations in Europe contains up to 139 microg/L mostly bound to humic substances, probably leaching from marine sediments in the aquifers. Even higher iodine contents have been found in Chinese waters, previously shown to associate with goitre and hypothyroidism. The aims were to elucidate speciation of high iodine groundwater from deep wells in China and to compare with high iodine waters from Europe. Water was sampled from eight wells in five villages along Bohai Bay, China. Macro-molecules and low molecular weight (MW) substances were separated by size exclusion chromatography (high performance liquid chromatography, Superose 12 HR 10/30, buffer 0.1 M Tris, pH 7.0). Organic material was evaluated by A280 and iodine in fractions measured by the Ce/As method after alkaline incineration. Iodine content of well water varied from 135 to 880 microg/L (median 287 microg/L). The amount of organic material in water was low with A280, <1-5 mAU. The chromatographic traces were similar between samples: One peak of iodine eluted around K (AV) 0.65 corresponding to MW 5 kDa (humic substances) and one peak at V (total) (iodide/low MW substances). The fraction of iodine in macro-molecules, suggested to be humic substances, varied from 8% to 70% (median 27%). Iodine and peak absorbance were associated (p = 0.006). In conclusion, iodine in iodine-rich deep well water in northern China may have marine origin and may associate with humic substances, comparable to shallow well iodine-rich water in Europe. High iodine intake from iodine-rich water suggests the cause of endemic goitre and hypothyroidism in some areas in China being iodine.

Autoregulation by Iodine of Thyroid Protein Synthesis: Influence of Iodine on Amino Acid Transport in Cultured Thyroid Cells*

Abstract: Studies were conducted to determine whether the inhibitory effect of iodine on thyroid protein synthesis could be explained by a reduction in intracellular amino acid transport. The nonmetabolizable amino acid [14C]cycloleucine was used as a probe for the L system of neutral amino acid transport in dog thyroid cells during the initial 24 h of primary culture. Uptake of cycloleucine was linear for up to 30 min. At all time points, cycloleucine transport was reduced in cells preincubated for 3 h in Nal (10−4 m). Inhibition (in a typical experiment) by Nal of cycloleucine transport (10 min) was 19%, 42%, and 69% at 10−6, 10−5, and 10−4 m iodide, respectively. Methimazole (3 IDM) together with iodide abolished the inhibitory effect of iodide on cycloleucine transport, implying the necessity of iodide organification. Methimazole itself did not significantly alter cycloleucine transport. T3, T4, MIT, and DIT similarly did not inhibit cycloleucine transport. Nal did not inhibit cycloleucine transport in cells la...

Selective copper(II) acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids.

Abstract: Copper(II) acetate/acetic acid/O2 and potassium iodide/tert-butylhydroperoxide systems are shown to affect the selective oxidation of ring-fused aminals to dihydroquinazolines and quinazolinones, respectively. These methods enable the facile preparation of a number of quinazoline alkaloid natural products and their analogues.

On the in vitro accumulation of inorganic iodide by surviving thyroid tissue with radioactive iodine as indicator1

Abstract: THE EARLY WORK of Marine (1915; Marine and Feiss, 1915) as well as the more recent observations with radioactive iodine (Hamilton and Soley, 1939; Hertz, Roberts, Means and Evans, 1940; LeBlond and Sue, 1940; Perlman, Morton and Chaikoff, 1941) leaves no doubt that the thyroid gland possesses an extraordinary capacity for the rapid removal of large amounts of circulating iodide. This iodine-concentrating capacity of thyroid tissue has not as yet received a satisfactory explanation. To obtain information on the mechanism involved, an investigation has been made here of the uptake of iodine and its subsequent conversion to thyroxine and diiodotyrosine by surviving thyroid slices in the presence of cyanide, sulfide, azide and sulfanilamide. It was shown earlier that these compounds inhibited the formation of thyroxine and diiodotyrosine by thyroid tissue, the first 3 by interfering with the cytochrome-cytochrome oxidase system (Schachner, Franklin and Chaikoff, 1943), the sulfanilamide by interfering in a ma...