STUDIES OF IODINE METABOLISM IN ICELAND

1964 ◽  
Vol 46 (4) ◽  
pp. 679-683 ◽  
Author(s):  
W. D. Alexander ◽  
Th. Veiger Gudmundsson ◽  
M. M. Bluhm ◽  
R. McG. Harden
Keyword(s):  
Thyroid Gland ◽  
Iodine Content ◽  
Iodine Uptake ◽  
Hormone Production ◽  
High Iodine ◽  
Iodine Level ◽  
Iodine Metabolism ◽  
Inorganic Iodine

ABSTRACT The relation between plasma inorganic iodine level, thyroid clearance and absolute iodine uptake of the thyroid gland has been studied in Iceland and compared with results obtained in Glasgow using identical methods. In Iceland the plasma inorganic iodine (PII) is higher than in Glasgow due to the high iodine content of the diet and the thyroid clearance lower. This adjustment is, however, incomplete, relatively high PII levels being associated with a low thyroid clearance and a raised absolute uptake by the thyroid. There was no evidence of increased hormone production as reflected in the serum PBI.

A COMPARATIVE STUDY OF IODINE METABOLISM IN PREGNANCY, SPORADIC GOITRE AND THYROTOXICOSIS

1965 ◽  
Vol 48 (1) ◽  
pp. 14-22 ◽  
Author(s):  
S. A. Aboul-Khair ◽  
J. Crooks
Keyword(s):  
Comparative Study ◽  
Pregnant Women ◽  
Iodine Deficiency ◽  
Physiological Responses ◽  
Iodine Uptake ◽  
Thyroid Activity ◽  
Deficiency State ◽  
Iodine Metabolism ◽  
Inorganic Iodine ◽  
In Pregnancy

ABSTRACT Studies of iodine metabolism have been carried out in 15 pregnant women, 33 cases with sporadic goitre and 11 with thyrotoxicosis. A low plasma inorganic iodine was common to the three groups. In pregnancy and sporadic goitre the thyroid clearance of iodine was elevated and the absolute iodine uptake normal. A high thyroid clearance of iodine in thyrotoxicosis was associated with a high absolute iodine uptake. The results suggest that both pregnancy and sporadic goitre are physiological responses to an iodine deficiency state while the iodine deficiency state of thyrotoxicosis is secondary to increased thyroid activity.

Calcium and metabolism of I131 in rats and homogenates of rat thyroid

1961 ◽  
Vol 200 (5) ◽  
pp. 1023-1026 ◽  
Author(s):  
Yaro Ribeiro Gandra ◽  
John G. Coniglio
Keyword(s):  
Thyroid Tissue ◽  
Iodine Content ◽  
In Vitro Studies ◽  
Iodine Uptake ◽  
Total Iodine ◽  
Organic Iodine ◽  
Free Iodine ◽  
Inorganic Iodine ◽  
Rat Thyroid

The goitrogenic effect of calcium was studied by the use of I131 in intact rats and in rat thyroid slices. Rats receiving excess dietary calcium had larger thyroids than controls. Enlargement of the thyroid was accompanied by increased content of inorganic iodine and decreased content of organic iodine. In vitro studies showed that thyroid enlargement was associated with greater total iodine uptake. Addition of calcium to the incubation medium decreased the total iodine uptake of thyroid slices. The reduction occurred as a consequence of interference with the conversion of inorganic iodine to organic iodine. No decrease in inorganic iodine content was observed. The ratios of bound iodine to free iodine were constantly smaller in the thyroid groups receiving calcium supplement. The results of the in vitro studies suggest that calcium interference is due, at least in part, to a direct effect on thyroid tissue.

»ENDEMIC COAST GOITRE« IN HOKKAIDO, JAPAN

1965 ◽  
Vol 50 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Hoji Suzuki ◽  
Tadashi Higuchi ◽  
Kunio Sawa ◽  
Sachiya Ohtaki ◽  
Yoshihiko Horiuchi
Keyword(s):  
Marked Decrease ◽  
Thyroid Tissue ◽  
Normal Range ◽  
Northern Island ◽  
Iodine Level ◽  
Iodine Metabolism ◽  
The Mean ◽  
Inorganic Iodine ◽  
Usual Diet ◽  
Made In

ABSTRACT A survey of goitre was made in the goitrous regions on the coast of Hokkaido, the northern island of Japan. Prevalence of goitre was confirmed in Hidaka coast and Rishiri Island. All goitrous patients were clinically euthyroid. The usual diet of the inhabitants of these districts consisted of a large quantity of iodine-rich seaweeds. Urinary excretion of iodine in five patients exceeded 20 mg per day. Studies of 131I and 127I metabolism were performed both during ingestion and after restriction of seaweed. When the patients were taking their usual diet, the mean thyroidal 131I uptake in 57 patients was 9.6% at 3 hours and 11.7% at 24 hours. In five of seven patients plasma inorganic iodine and thyroidal iodine space were markedly increased. Significant discharge of thyroidal 131I followed administration of thiocyanate. After withdrawal of seaweed from their usual diet, the plasma inorganic iodine was below 2 μg/100 ml but the thyroidal stable iodine uptake was higher than normal, depending on increase in thyroidal 131I clearance rate. No discharge was shown by thiocyanate block. Plasma PBI and thyronine-iodine level and serum T3 resin uptake were within the normal range. Radiochromatography of the thyroid tissue of the goitrous patients showed an increase in MIT/DIT ratio and a decrease in T3 + T4 proportion. No evidence for peripheral defect in DIT-131I deiodination was obtained. In a few patients restriction of seaweed induced a marked decrease in the size of goitre. The major cause of the endemic coast goitre seems to be excessive and longstanding intake of iodine from seaweed, and the similarities of iodine metabolism between the endemic coast goitre and iodide goitre arc discussed.

scholarly journals Amiodarone compared with iodine exhibits a potent and persistent inhibitory effect on TSH-stimulated cAMP production in vitro: a possible mechanism to explain amiodarone-induced hypothyroidism

1999 ◽  
pp. 241-249 ◽  
Author(s):  
V Pitsiavas ◽  
P Smerdely ◽  
SC Boyages
Keyword(s):  
Cholera Toxin ◽  
Iodine Content ◽  
Inhibitory Effect ◽  
Tsh Receptor ◽  
Camp Production ◽  
Inhibitory Effects ◽  
High Iodine ◽  
Receptor Interactions ◽  
Inorganic Iodine

Amiodarone (AMD) is a powerful anti-arrhythmic drug used for the treatment of a wide variety of cardiac arrhythmias and its most striking feature is its high iodine content. Thyroid dysfunction is a limiting side-effect of the drug and both AMD-induced hypothyroidism (AIH) and AMD-induced thyrotoxicosis (AIT) are reported. To examine the hypothesis that altered bioavailability of iodine is a contributing event in the pathogenesis of AIH, we compared the effects of AMD and inorganic iodine in vitro on events involved in the process of thyroid autoregulation. FRTL-5 cells and JP26 CHO cells (transfected with the human TSH receptor) were exposed to AMD or NaI in the presence of TSH, and cAMP production was measured as an indicator of cellular function. Forskolin and cholera toxin were also used to determine the possible target sites of AMD and iodide. Our results indicated that there was a difference between the effects of AMD versus those of physiological doses of iodide. The inhibitory effects of AMD occurred at lower concentrations of iodide than those seen in the NaI-treated cells. The effects of AMD were irreversible indicating a possible persistence of the Wolff-Chaikoff effect due to a constant high intracellular iodide level. The inhibitory effects of AMD (also seen at supraphysiological doses of iodide) were partially overcome by forskolin but not by cholera toxin indicating an effect on TSH receptor interactions with the other signal transduction elements such as G proteins and adenylate cyclase. The persistence of the Wolff-Chaikoff effect through loss of autoregulation may be a mechanism of the observed hypothyroidism in some patients taking AMD. The combined effects of the constant release of iodide together with the drug toxicity may be the mechanism for the observed effects.

scholarly journals Further Observations on the Occurrence of Iodine in Relation to Endemic Goitre in New Zealand and on Iodine Metabolism

1931 ◽  
Vol 31 (4) ◽  
pp. 493-522 ◽  
Author(s):  
C. E. Hercus ◽  
H. A. A. Aitken ◽  
H. M. S. Thomson ◽  
G. H. Cox
Keyword(s):  
New Zealand ◽  
Thyroid Gland ◽  
Iodine Content ◽  
Iodine Intake ◽  
Whole Body ◽  
Nodular Goitre ◽  
Iodised Salt ◽  
Iodine Metabolism ◽  
Iodine Excretion ◽  
Residential Institutions

1. Most artificial manures are found to have some effect in increasing the iodine content of crops, particularly superphosphate.2. Marked differences are found between the iodine contents of Samoan and New Zealand foodstuffs corresponding to the non-goitrous condition of Samoa and the partial endemicity of New Zealand.3. Investigation of the dietaries of fifteen residential institutions showed that improvement in provision of iodine was necessary in many cases by using fish at least twice a week, raising the daily ration of milk to 1 pint per head, and employing iodised salt for table and culinary purposes.4. Dietetic experiments indicate (i) that on a change of diet adjustment of iodine metabolism may take a considerable time, (ii) that iodised salt is most effective in promoting storage of iodine when associated with a meat diet.5. Iodine excretion is found to decrease much more rapidly under fasting than on a diet very low in iodine.6. Iodised salt has the effect of adjusting the excretion of goitrous adults to the normal non-goitrous value.7. The iodine content of the blood is found to be lower than normal in cases of simple colloid and simple nodular goitre, though it may range from low to abnormally high in cases of Graves' disease. In all types of goitre the thyroid gland is low in iodine.8. The ratio of thyroid iodine to total bodily iodine is about 12 per cent. in the case of the white rat under ordinary conditions, but the ratio is found to vary considerably with the iodine intake.9. Great differences in the ratio of the weight of the thyroid gland to that of the whole body are found among different species of animals, the ratio being higher for the dog than for the monkey.10. Variations in commercial samples of iodised salts are recorded and discussed.11. Data are given in regard to the iodine and chlorine content of rainwater in different localities.

scholarly journals Miscellaneous Studies on the Iodine and Goitre Problem in New Zealand

1933 ◽  
Vol 33 (1) ◽  
pp. 55-79 ◽  
Author(s):  
C. E. Hercus ◽  
H. A. A. Aitken
Keyword(s):  
New Zealand ◽  
Thyroid Gland ◽  
Mental Hospital ◽  
Pacific Coast ◽  
Direct Action ◽  
Iodine Content ◽  
Similar Species ◽  
The Pacific ◽  
Inorganic Iodine

1. Methods for the estimation of iodine in natural products are described.2. Common sea weeds on the Pacific coast of Otago have an iodine content of the same order as similar species on the Pacific coast of British Columbia.3. In Cystophora retroflexa, which contains over 0·1 per cent, of iodine, 70–80 per cent, of the iodine appears to be in inorganic or loosely bound combination. Precipitation and colour tests indicate that di-iodotyrosine is also present.4. Observations are recorded of the iodine content of kelp-feeding and other fish.5. Administration of anaesthetics produces fluctuations in the concentration of blood iodine in rabbits, the effect persisting after removal of the thyroid gland. Experiments in vitro suggest that only in the case of inorganic iodine could a redistribution of iodine between tissues and serum be brought about by the direct action of anaesthetics.6. New Zealand cabbage possesses goitrigenous properties for rabbits but in a much smaller degree than American cabbage.7. The urinary excretion of Samoans is compared with that of inhabitants of Christchurch Mental Hospital.8. The incidence and course of development of goitre at Christchurch Mental Hospital is discussed.9. Values are given for the iodine content of Otago pigs' thyroids.

THIOURACIL TREATMENT IN PREGNANCY AND LACTATION IN THE DOG

1962 ◽  
Vol 40 (3) ◽  
pp. 430-440 ◽  
Author(s):  
K. E. Arosenius ◽  
H. Derblom ◽  
G. Nylander
Keyword(s):  
Thyroid Gland ◽  
List Type ◽  
Histological Changes ◽  
Morphological Effect ◽  
Iodine Metabolism ◽  
Pregnancy And Lactation ◽  
In Pregnancy

ABSTRACT The offspring of bitches treated with thiouracil during pregnancy and lactation were studied with regard to certain aspects of iodine metabolism and also to the morphological effect on the thyroid gland, as compared with controls of the same age and weight. At the age of six months, when the dogs were virtually fully grown, the thyroid gland still exhibited the effects of the thiouracil treatment of the mothers as manifested by an increased uptake of 131I, enlargement, and histological changes of a hyperplastic type. The significance of these deviations from normal iodine metabolism and morphology is discussed with particular reference to the dangers of thiouracil medication during pregnancy.

DIE ZUSAMMENSETZUNG DER JODHALTIGEN VERBINDUNGEN UND IHRE BEZIEHUNG ZUM JODUMSATZ IN EUTHYREOTEN STRUMEN

1962 ◽  
Vol 41 (4) ◽  
pp. 584-594 ◽  
Author(s):  
Dankwart Reinwein ◽  
Erich Klein
Keyword(s):  
Column Chromatography ◽  
Iodine Content ◽  
High Plasma ◽  
Secretion Rate ◽  
Total Iodine ◽  
Iodine Compound ◽  
Hormonal Secretion ◽  
Carrier Free ◽  
Iodine Metabolism ◽  
Diffuse Goiter

ABSTRACT The iodine metabolism was investigated in 29 patients with euthyroid non-endemic diffuse goiter. 1 to 14 days before thyroidectomy the patients received carrier-free 131I. The chemical iodine fractions (PBI, BEI and iodide) of the thyroid and the labelled iodine compound were analyzed by means of paper- and column chromatography. In one gland the total iodine content varied only by ± 19.6% of the average, the relative shares of PBI, BEI and iodide as well as that of the iodoamino acids being equal. Monoiodotyrosine, diiodotyrosine and thyroxine were found in the thyroid homogenate without hydrolysis. The homogenate after hydrolysis contained more iodotyrosines at the expense of iodothyronines than do normal glands. 17 goiters with normal 131I-uptake showed a high total iodine content (14.2 ± 5.0 mg) whilst 9 goiters with an increased 131I-uptake had low values (3.58 ± 0.6 mg). The opposite was found for the relative shares of BEI with the chromatographically isolated iodothyronines thyroxine, triiodothyronine and an unidentified iodine compound. Goiters with »high plasma PB131I« were characterized by a faster transfer of 131I into the more heavily iodinated compounds than is found in glands with a normal hormonal secretion rate. The highest values for the iodothyronines were found in goiters with increased 131I-uptake together with a high hormonal secretion rate. From this study it appears that the changes in the iodine-poor glands are due to a defective exo- or endogenous iodine supply. The observed alterations in iodine-rich glands are probably induced by a faulty iodine utilization characterized by an incomplete iodotyrosyl-coupling defect.

QUANTITATIVE STUDIES OF IODINE METABOLISM IN SPORADIC, NON-TOXIC GOITRE

1974 ◽  
Vol 76 (1) ◽  
pp. 67-73 ◽  
Author(s):  
H. Agerbæk ◽  
S. E. Jensen
Keyword(s):  
Iodine Deficiency ◽  
Iodine Uptake ◽  
Quantitative Studies ◽  
Euthyroid State ◽  
Iodine Metabolism ◽  
Dynamic Patterns ◽  
Perchlorate Discharge Test ◽  
Normal Controls ◽  
Discharge Test

ABSTRACT In 129 patients with non-toxic goitre and 27 normal controls, thyroid dynamic patterns were estimated in an attempt to elucidate pathogenesis. The clinically euthyroid state was confirmed by measurement of PBI, T3-sephadex uptake and BMR. Thyroid clearance (th. cl.), plasma iodide (PII), and absolute iodine uptake (AIU) were determined and a perchlorate discharge test performed. Twenty patients (16%) had a high AIU and were thus suspected of having dyshormonogenesis; nine were thoroughly investigated and in six dyshormonogenesis was found. Both normals and non-toxic goitre patients had a low PII, but in the goitrous patients values were lowest. The thyroid clearance of iodide was significantly higher in the goitre patients, suggesting iodine deficiency to be a major aetiologic factor for goitre formation. AIU was higher in the goitre patients than in normals, suggesting a larger iodine leakage from the thyroid in these patients.

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