Abstract
Sodium fluoride (CAS 7681-49-4) 5-20 micromol/L in the extracellular space inhibited insulin secretion by isolated Langerhans islets stimulated with glucose. Insulin secretion followed a negative exponential function. This phenomenon is rapidly reversible. Perfusion of pancreatic tissue (rat) in vivo with stimulatory levels of glucose revealed that 20 micromol/L fluoride in the perfusion fluid inhibited the initial and sustained phases of insulin secretion to 15% of that of controls. The stimulatory effects of the ionophore A23187, phorbol-ester and forskolin on the secretion of insulin of isolated rat Langerhans islets in vitro were inhibited by 20 micromol/L fluoride. The results suggested that fluoride affects some stage of insulin secretion situated below the cascade of events that include the participation of calmodulin, protein-kinase C and cyclic AMP.
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Fundamental and applied studies on transport and metabolism of electrolytes and glucose--aim to contact with molecular biology. [Article in Japanese]
The authors' research focuses on polyuria, natriuresis, glucosuria, glycemia, and renal calcification in occupational lead poisoning and endemic fluorosis. Changes in electrolyte mobilization and in glucose metabolism and transport following the administration of lead compounds or fluoride were examined to elucidate these mechanisms. The results suggest fundamental approaches to the
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Changes in the metabolism of glucose and calcium following a single large dose of fluoride to rats
Serum glucose level was elevated immediately after ip administration of a single large dose of fluoride (NaF 35 mg/kg) to rats. The elevation of serum glucose was markedly suppressed by adrenalectomy, dibenamine or propranolol, but not by thyroid-parathyroidectomy. Elevation of serum glucose was found to be associated with enhancement of
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Fluoride exposure impairs glucose tolerance via decreased insulin expression and oxidative stress.
Chronic exposure to high fluoride (F(-)) may lead to local tissue disturbances, known as fluorosis. F(-) is an oxidising agent and a well-known reversible enzymatic inhibitor that interferes with the enzyme activity of at least 80 proteins. The goals of the current study were to evaluate whether F(-) exposure affected
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Central nervous system mediation of fluoride hyperglycemia in the rat.
The hyperglycemia which accompanies acute fluoride toxicity in the rat is mediated by epinephrine released from the adrenal medulla. Bilateral splanchnicotomy prevented this response to fluoride. Ganglionic blockade diminished the hyperglycemic response in unanesthetized animals but not in pentobarbital-anesthetized animals. Microinjections of fluoride into the lateral ventricle elicited a rapid
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Inhibition of thyroid secretion by sodium fluoride in vitro
NaF mimicked the activation by thyrotropin of iodide binding to proteins and of glucose C-r oxidation but not the accumulation of intracellular colloid droplets or the stimulation of secretion in dog thyroid slices in vitro. On the contrary, NaF inhibited the two latter thyrotropin effects. The inhibitory action of F-
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Fluoride & Impaired Glucose Tolerance
The proper regulation of blood glucose levels is essential to good health. When the body's ability to regulate blood glucose levels falters, as occurs in diabetes mellitus, chronic elevated glucose levels (hyperglycemia) can lead to serious complications. These consequences include damage to the kidneys, nervous system, cardiovascular system, retina, legs
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Fluoride Sensitivity Among Diabetics
This section on Diabetes includes: • Fluoride & Impaired Glucose Tolerance • Fluoride & Insulin • Fluoride Sensitivity Among Diabetics • Fluoridated Water Causes Severe Dental Fluorosis in Children with Diabetes Insipidus • NRC (2006): Fluoride’s Effect on Glucose Metabolism “The present study showed that aortae and mesenteric arteries from streptozotocin-induced diabetic rats exhibited greater contractions
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NRC (2006): Fluoride's Effect on Glucose Metabolism
This section on Diabetes includes: • Fluoride & Impaired Glucose Tolerance • Fluoride & Insulin • Fluoride Sensitivity Among Diabetics • Fluoridated Water Causes Severe Dental Fluorosis in Children with Diabetes Insipidus • NRC (2006): Fluoride’s Effect on Glucose Metabolism The following discussion is from pages 258-260 of the NRC’s report’s “Fluoride in Drinking Water: A Scientific
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Fluoride & Insulin
Insulin is a hormone produced by the pancreas that is responsible for maintaining appropriate levels of glucose in the blood. Insulin allows the body’s cells to take up glucose from the blood, and either use it as an energy source or store it as glycogen. Blood glucose levels in diabetics
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Fluoridated Water Causes Severe Dental Fluorosis in Children with Diabetes Insipidus
This section on Diabetes includes: • Fluoride & Impaired Glucose Tolerance • Fluoride & Insulin • Fluoride Sensitivity Among Diabetics • Fluoridated Water Causes Severe Dental Fluorosis in Children with Diabetes Insipidus • NRC (2006): Fluoride’s Effect on Glucose Metabolism Excessive exposure to fluoride causes a defect of the tooth enamel known as dental fluorosis. In
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