Thyroid Iodine Concentration and Total Thyroid Iodine in Normal Subjects and in Endemic Goitre Subjects

Abstract

Thyroid iodine concentration and total thyroid iodine were determined by an automated technique by means of the ceric arsenious acid reaction in 42 males and 13 females. The thyroids were taken from autopsy material in a region with a low dietary intake. The accuracy of the method to estimate iodine was checked by neutron activation analysis. There was an excellent correlation between the iodine contents of thyroid specimens, when measured by chemical or by activation analysis. The mean iodine concentration was 1.86 mg/g dry weight and was found to be lower than in non-goitrous regions. In goitres, the mean iodine concentration was significantly lower, and the mean total thyroid of normal weight. There was no significant difference in iodine concentration and total iodine between males and females. The thyroid iodine concentration did not depend upon age in adults. The data were log normally distributed. It was established that mean iodine concentrations under 2 mg/g dry weight or 0.45 mg/g fresh weight are to be regarded as an important index of iodine deficiency.

ICRP Publication 137: Occupational Intakes of Radionuclides: Part 3

“…The rate of accumulation of organic iodine by the thyroid and the rate of loss of iodine from the thyroid both appear to increase at high levels of iodine intake, but the mass of iodine secreted as thyroid hormones appears to remain unchanged (Koutras et al., 1964; Fisher et al., 1965; Nagataki et al., 1967; Ohtaki, 1967; Harrison, 1968; Fisher and Oddie, 1969a). (220) In adults with an iodine-sufficient diet, the thyroid typically stores 5–15 mg of hormonal iodine (Riggs, 1952; Fisher and Oddie, 1969b; Hellstern et al., 1978; Handl et al., 1984; Shapiro et al., 1994; Hays, 2001). Estimates of the rate S of secretion of hormonal iodine by the thyroid (µg I d −1 ) in individual euthyroid adult humans range from less than 30 µg d −1 to more than 150 µg d −1 (Riggs, 1952; Berson and Yalow, 1954; Stanbury et al., 1954; Ingbar and Freinkel, 1955; Gregerman et al., 1962; Fisher et al., 1965; Fisher and Oddie, 1969a; Zvonova, 1989).…”

“…(220) In adults with an iodine-sufficient diet, the thyroid typically stores 5–15 mg of hormonal iodine (Riggs, 1952; Fisher and Oddie, 1969b; Hellstern et al., 1978; Handl et al., 1984; Shapiro et al., 1994; Hays, 2001). Estimates of the rate S of secretion of hormonal iodine by the thyroid (µg I d −1 ) in individual euthyroid adult humans range from less than 30 µg d −1 to more than 150 µg d −1 (Riggs, 1952; Berson and Yalow, 1954; Stanbury et al., 1954; Ingbar and Freinkel, 1955; Gregerman et al., 1962; Fisher et al., 1965; Fisher and Oddie, 1969a; Zvonova, 1989).…”

Elemental analysis of the thyroid by laser induced breakdown spectroscopy

“…This result demonstrates that the 746.9 nm line belongs to iodine and that higher LIBS intensity corresponds to higher iodine concentration. Note that these concentrations are close to, but above physiological values as the normal thyroid (0 ppm) has iodine concentration in excess of 1000 ppm [18,19]. Figure 5(a) shows the normalized LIBS spectra from the thyroids of control subjects, subjects treated for 6 days with 0.05% iodine solution, and subjects treated for 12 days.…”

Thyroid: Iodine Beyond the Thyronines

“…Moreover when the intrathyroidal iodide content was significantly decreased thyroid enlargement occurred before a significant increase in TSH serum levels [6][7][8], which explains the coexistence of goiter with normal serum TSH levels in areas of Argentina [9]. Hellstren et al [10] observed an inverse relationship between goiter size and the iodine content in the thyroid.…”