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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Stimulation of cAMP accumulation and superoxide production in human neutrophils and monocytes
The effect of sodium fluoride (NaF) on superoxide generation and cyclic adenosine monophosphate (cAMP) levels in human neutrophils and monocytes was investigated. NaF (greater than 10 mM) stimulated superoxide (O2-) production in both cell types in a time dependent manner. NaF (0.5 to 20 mM) increased cAMP levels by 1.5-
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Predominant contribution of the G protein-mediated mechanism to NaF-induced vascular contractions in diabetic rats: association with an increased level of G(qalpha) expression.
The purpose of this study was to determine the mechanism responsible for alterations in NaF-induced contractions of blood vessels from streptozotocin-induced diabetic rats. In the presence of AlCl(3), NaF (>/=7.5 mM) produced significantly greater contractions in diabetic aorta and mesenteric artery compared with age-matched controls. Pretreatment with 1 microM nifedipine
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Aluminum: a requirement for activation of the regulatory component of adenylate cyclase by fluoride
Activation of the purified guanine nucleotide-binding regulatory component (G/F) of adenylate cyclase by F- requires the presence of Mg2+ and another factor. This factor, which contaminates commercial preparations of various nucleotides and disposable glass test tubes, has been identified as Al3+. In the presence of 10 mM Mg2+ and 5
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Sodium fluoride evoked histamine release from mast cells. A study of cyclic AMP levels and effects of catecholamines
Calcium triggers the secretion of histamine from mast cells after previous exposure to sodium fluoride. The secretory process can be divided into a fluoride-activation step and a calcium-induced secretory step. It was observed that the fluoride-activation step is accompanied by an elevation of cAMP levels within the cells. The attained
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Cognitive Decline of Rats with Chronic Fluorosis Is Associated with Alterations in Hippocampal Calpain Signaling.
The study was designed to evaluate an influence of excessive fluoride (F-) intake on cognitive capacities of adult rats and on proteins of memory-related calpain signaling in hippocampus. Control animals were given water with natural F- content of 0.4 ppm; rats from other groups consumed the same water supplemented with 5,
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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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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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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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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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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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