scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: Maximal goiter production was compared in rats fed low iodine diets containing various antithyroid anions and ReO4 and C1O were antigoitrogenic when fed together with propylthiouracil, that is, goiters were reduced to a size approaching that following anion treatment alone.
Abstract: 1. Maximal goiter production was compared in rats fed low iodine diets containing various antithyroid anions. Even though no significant organic iodine formation occurred, goiters resulting from the feeding of ReO4-, ClO4, BF4 or NOT weighed 20–25 mg/100 g body weight, whereas goiters produced with propylthiouracil were nearly twice as large (40–45 mg/100 g). SCN- was intermediate between these groups. Thyroidal iodine depletion and serum PBI depression were equal in all groups. No histological differences could be established. The ability to produce a certain degree of thyroid enlargement is a function of the K1 for I- transport in thyroid slices. 2. ReO4 and C1O.T were antigoitrogenic when fed together with propylthiouracil, that is, goiters were reduced to a size approaching that following anion treatment alone. This antigoitrogenic effect occurred at lower doses than the goitrogenic effect. 3. Circulating TSH levels were not depressed when ReO or ClO4 was fed with propylthiouracil. While there appeare...

47 citations

Journal ArticleDOI
TL;DR: Iodine requirements are increased during pregnancy and lactation and adequate iodine intake is important for normal brain development of the fetus/newborn child.
Abstract: Iodine requirements are increased during pregnancy and lactation and adequate iodine intake is important for normal brain development of the fetus/newborn child. The aim of the present study was to evaluate the extent to which this increase in iodine requirement is met in pregnant women living in various regions of Denmark. One hundred and fifty-two healthy pregnant women admitted to five different Danish departments of obstetrics participated in the study. Iodine status was evaluated by measurement of iodine in spot urine at day five after delivery and by careful history of the intake of iodine containing vitamin/mineral tablets. Approximately one third of the women had received tablets containing iodine. In women who had not received iodine supplementation urinary iodine was low with a median value of 39.7 micrograms/g creatinine (Aalborg 28, Randers 33, Ringkobing 34, Arhus 43 and Copenhagen 62 micrograms/g creatinine). These values are far below internationally recommended levels. The consequences remain to be evaluated and no firm recommendations can be given. It seems reasonable, however, to recommend a high intake of food containing iodine (e.g. milk products) during pregnancy and lactation. Since nearly all the women took some kind of vitamin/mineral supplementation it could be considered to advocate intake of vitamin/mineral tablets containing iodine.

47 citations

Journal ArticleDOI
TL;DR: It appeared that the enzyme catalyzes thyroid hormone synthesis at a slower rate than iodination, a substrate of the iodination reaction, may also have other effects on the activity of thyroid peroxidase.
Abstract: The kinetics of tyrosine iodination and of thyroxine synthesis in thyroglobulin, different reactions catalyzed by the sane enzyme (thyroid peroxidase), have been compared. Thyroxine synthesis always began after a lag period of 3–5 min. This lag was constant whatever the rate of iodination; this rate of iodination was increased either by increasing the concentration of iodide or enzyme or by decreasing the concentration of thyroglobulin. Increasing the rate of iodination resulted in increasing the number of iodine atoms incorporated during the lag period. Thus the lag observed for thyroxine synthesis was constant and did not depend on the fact that free iodide or non-iodinated tyrosine residues of thyroglobulin were exhausted before thyroxine synthesis occurred. Finally, it appeared that, whatever the explanation of the lag, the enzyme catalyzes thyroid hormone synthesis at a slower rate than iodination. The existence of a lag also allowed us to prepare thyroglobulin samples with different iodine contents but without thyroid hormones. Thus iodination and thyroxine synthesis could be studied independently and the following results were obtained. 1 Iodotyrosine residues which can couple to form thyroxine are made considerably before coupling occurs. 2 H2O2 is required for coupling of these hormonogenic residues; thus the coupling reaction requires enzymic oxidation of the iodotyrosine residues. 3 In addition a strict requirement for iodide was needed for coupling: the requirement was dependent on the concentration of iodide. Thus iodide, a substrate of the iodination reaction, may also have other effects on the activity of thyroid peroxidase.

47 citations

Journal ArticleDOI
TL;DR: In this paper, a new series of iodine-containing compounds was reported as catalysts for the direct and selective oxidation of methane to methyl sulfates (especially mono methyl sulfate) in 65% oleum.
Abstract: A new series of iodine-containing compounds is reported as catalysts for the direct and selective oxidation of methane to methyl sulfates (especially mono methyl sulfate) in 65 wt.% oleum. The solubility of elemental iodine in 65 wt.% oleum at 180 °C was found to be ca. 34 mmol/l with only the dissolved part of the iodine as the active catalyst. A mathematical model for the relationship between the initial reaction rate and the iodine concentration is given. It is found that the iodine-catalyzed reaction is first order for methane (up to above 100 bar), but 0.5 order for iodine. Suitable reaction temperatures are in the range 170–190 °C. Besides elemental iodine, many compounds containing iodine, such as KI, NaI, CH3I, I2O5, KIO3 and KIO4, also catalyze the methane oxidation to methyl sulfates in oleum in the same manner and at the same iodine concentration indicating that they are converted into the same catalytic intermediate. High performance liquid chromatography and gas chromatography and other methods was used to clarify the stoichiometry of the proposed reaction schemes. Titration results showed that, when methane was in excess compared to the amount of SO3 in the beginning of an experiment, almost pure sulfuric acid (99.06±0.15%) was the result in the end of the experiment. Gas chromatograph measurements showed that 4.6% of the consumed methane was converted to CO2 while the overall selectivity of methane to methyl sulfates was found to be ca. 92%.

47 citations

Journal ArticleDOI
TL;DR: The data suggest that KA interrupts thyroid function, primarily by inhibiting iodine intake, consequently causing a decrease in serum T(3) and T(4).
Abstract: To clarify the mechanism of tumorigenesis by kojic acid (KA), dose and time dependence of iodine uptake in the thyroid gland and serum thyroid stimulating hormone (TSH) and thyroid hormone levels were investigated in F344 rats fed a diet containing 2% KA. After 4 weeks, thyroid hyperplasia was apparent in males, associated with a decrease in (125)I uptake into the thyroid gland to only 3% of that in controls. The serum triiodothyronine (T(3)) and thyroxine (T(4)) levels dropped to 0.36 ng/ml, 1.7 micrograms/dl from the initial values of 0.61 ng/ml, 4.0 micrograms/dl and TSH increased seven times to 15 ng/ml. In females, the effects on thyroid weight and (125)I uptake were less prominent, although the changes in serum T(3), T(4) and TSH levels were similar to those in males. Time-dependent changes in serum T(3), T(4) and TSH levels correlated with the inhibition of iodine uptake in the thyroid. Inhibition of organic iodine formation was only observed after 3 weeks treatment. On return to the control diet, normal serum T(3), T(4) and TSH levels became evident within 48 h in both sexes. These data suggest that KA interrupts thyroid function, primarily by inhibiting iodine intake, consequently causing a decrease in serum T(3) and T(4). Increased TSH from the pituitary gland in turn stimulates thyroid hyperplasia, which is reversible on withdrawal of KA.

47 citations


Network Information
Related Topics (5)
Amino acid
124.9K papers, 4M citations
81% related
Reagent
60K papers, 1.2M citations
77% related
Cobalt
69.8K papers, 1.2M citations
77% related
Nucleic acid
53.2K papers, 1.2M citations
76% related
Thyroid
68.8K papers, 1.5M citations
76% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023748
20221,361
2021155
2020154
2019158
2018186