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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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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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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Pathological changes in the tissues of rats (albino) and monkeys (macaca radiata) in fluorine toxicosis
1. Stomach, duodenum, small intestine, kidney, liver, spleen, skin, heart, aorta, lungs, brain, pancreas, adrenals, thyroid and parathyroid of rats and monkeys suffering from chronic fluorosis have been histologically examined. 2. Fluorine has not been found to have any effect on the heart muscle, aorta, skin and parathyroids, whereas it has
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Hyperplastic nodules of thyroid parafollicular cells (C cells) in rats induced by prolonged low dose ingestion of NaF
In rats which received drinking water containing 0, 3, 6, 12, 25 ppm NaF (F-) for 20 months, hyperplastic nodules, consisting of thyroid parafollicular cells (C cells) appeared in all F- groups, particularly in those which received 12 and 25 ppm. By immuno-histochemistry and electron microscopy, both calcitonin and characteristic
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Ameliorative effect of resveratrol against fluoride-induced alteration of thyroid function in male wistar rats
Resveratrol (3,4,5-trihydroxystilbene), a polyphenol and well-known natural antioxidant has been evaluated for its protective effect against fluoride-induced metabolic dysfunctions in rat thyroid gland. Fluoride, the most abundant anions present in groundwater throughout the world, creates a major problem in safe drinking water and causes metabolic, structural, and functional injuries in
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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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Is fluoride-induced hyperthyroidism a cause of psychosis among East African immigrants to Scandinavia?
When people with a compensated fluoride-induced hypothyroidism move to a low-fluoride area, the fluoride-induced inhibition of the production of thyroid hormones ceases. In Scandinavia, the dietary intake of iodine is usually quite high due to iodized table salt and easy access to marine fish. Under these conditions, the elevated capacity for production of thyroid hormones may result in hyperthyroidism.
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The Relationship Between Fluoride Exposure & Goitre in South Africa
As a general rule simple goitre, irrespective of the cause, can be very, or fairly, satisfactorily combated by an adequate increase in man's daily iodine intake, except when the enlargement of the gland is due to the ingestion of excessive amounts of fluorine. The only correct solution to fluorine-induced endemic goitre is the removal of this element from the drinking water.
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Fluoride & Goiter
Goitre (aka goiter) is an enlargement of the thyroid gland that in some cases can produce visible swelling in the neck. The main cause of goitre is iodine deficiency. Goitre can also be caused by other things, including hypothyroidism and substances that cause goitre (goitrogens). Since as far back as the
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Fluorine in the Aetiology of Endemic Goitre
The distribution of endemic goitre in the Punjab and in England is related to the geological distribution of fluorine and to the distribution of human dental fluorosis (mottled enamel). Inquiry showed the presence of dental fluorosis among school-children in two areas of Somerset where two previous observers had recorded a high incidence of goitre, and the absence of dental fluorosis in an adjoining area selected as control where endemic goitre was absent.
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