Abstract
Effects on Ca++ translocation and [Ca++]i were studied in dog thyroïd cell monolayers using both 45Ca++ efflux and the indicator quin-2. Carbamylcholine, a non hydrolysable analog of acetylcholine, through muscarinic receptors, and to a lesser extent TRH and PGF2 alpha increased both these parameters. [Ca++]i increased by 171, 100 and 75% respectively over a basal level of 66 +/- 17 nM (mean +/- SD). The response to carbamylcholine was biphasic. A transient increase in [Ca++]i was followed by a more sustained phase where the [Ca++]i was slightly higher than the basal level. Only the first phase was insensitive to extracellular Ca++ depletion. This phase is probably due to a release of Ca++ from an intracellular store. NaF also induced a sustained rise in [Ca++]i dependent on extracellular Ca++ and affected 45Ca++ efflux. Our data provide direct evidence of an implication of intracellular Ca++ in the response of dog thyroïd cells to all these agents.
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Effect of sodium fluoride on the thyroid follicular cells and the amelioration by calcium supplementation in albino rats: A Light And An Electron Microscopic Study
Sodium fluoride was the first fluoride compound used in the fluoridation of drinking water and it is still commonly used for that purpose to prevent dental caries. It exerts toxic effects on many soft tissues and organs. The thyroid gland has a strong capacity for absorbing and accumulating fluoride. Objective: The
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Fluoride-induced thyroid dysfunction in rats: roles of dietary protein and calcium level.
To assess the roles of dietary protein (Pr) and calcium (Ca) level associated with excessive fluoride (F) intake and the impact of dietary Pr, Ca, and F on thyroid function, 144 30-day-old Wistar albino rats were randomly allotted to six groups of 24 (female:male = 1:1). The six groups were
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Is water fluoridation a hidden cause of obesity? Histological study on thyroid follicular cells of albino rats
Introduction: Fluoride in drinking water is known to exert both beneficial and detrimental effects on health. When consumed in excess, it is known to cause adverse effects including dental fluorosis, hip fracture, bone cancer, lower intelligence, and kidney toxicity plus goiter. Aim: This study was carried out to determine the histological
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[Chronic effects of fluorides on the pituitary-thyroid system in industrial workers].
Radioimmunologic study of thyrotropin and thyroid hormones in the blood of those engaged in fluorine production showed moderate functional changes of the hypophysis-thyroid gland system, not accompanied by clinical manifestations of hypo- or hyperthyreosis and caused by disorders of the regulatory chain and fluorine impact on thyroid hormones' metabolism at
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Long-term effects of various iodine and fluorine doses on the thyroid and fluorosis in mice
OBJECTIVE: To elucidate the participation of the independent and combined long term effect of various concentrations of iodine and fluorine on the pathogenesis of goiter and fluorosis in mice. METHODS: Nine drinking water supplies with different iodine and fluorine content were prepared by combination of potassium iodate and sodium fluoride solutions in bidistilled
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Fluoride Aggravates Thyroid Damage Caused by Excess Iodine Intake
Chinese researchers have found that the combination of excess fluoride with excess iodine caused greater reductions in IQ, or greater increases in goitre than either scenario by itself.
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NRC (2006): Fluoride's Impact on the Thyroid Gland
Several lines of information indicate an effect of fluoride exposure on thyroid function. It is difficult to predict exactly what effects on thyroid function are likely at what concentration of fluoride exposure and under what circumstances.
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Mikhailets (1996): Functional state of thyroid under extended exposure to fluorides
Abnormalities in the thyroid function characterized by a decreased iodine absorption function of the thyroid, a low level T3 syndrome, and a slight increase of the TSH level are observed in cases of chronic fluorine intoxication in the industrial workers.
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Fluoride, Water Hardness, and Endemic Goitre
Variations in goitre prevalence were found to correlate closely with the fluoride content (p=0-74; P<0-01) and with the hardness (p=0.77; P<0-01) of the water in each village. The effects of fluoride and water hardness seem to be independent.
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Fluoride Exposure Aggravates the Impact of Iodine Deficiency
A consistent body of animal and human research shows that fluoride exposure worsens the impact of an iodine deficiency. Iodine is the basic building block of the T3 and T4 hormones and thus an adequate iodine intake is essential for the proper functioning of the thyroid gland. When iodine intake is inadequate during infancy and
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