Abstract
The modulatory actions of fluoride on the function of the dihydropyridine-sensitive (L-type) Ca2+ channel were studied in rabbit cardiac myocytes. In cell-attached voltage-clamp experiments, using barium as the charge carrier, fluoride increased the activity of the Ca2+ channel dose-dependently. Low concentrations (<10 mM) of fluoride increased the number of traces with channel activities, and decreased the number of traces without channel activities, resulting in a net increase in the open-channel probability. The effect of 5 mM fluoride on the Ca2+ channel was inhibited by the presence of non-hydrolyzable guanosine diphosphate analog in the cell. On the other hand, high concentrations (>10 mM) of fluoride increased the open-channel duration, resulting in a marked increase in open-channel probability. A pretreatment of myocytes with a phosphatase inhibitor, okadaic acid, virtually abolished the additional effect of fluoride on the open-channel duration or open probability. A concentration of up to 75 mM fluoride had no effect on the Ca2+-channel activity when the myocytes were pretreated with a potent inhibitor of protein kinases, indicating that fluoride increased the Ca2+- channel activity via modulation of the phosphorylation state of the myocyte or the channel protein alone.
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Relationship between fluoride deposition and metastatic calcification in soft tissues of rat and guinea pig
Two studies have been conducted to investigate whether there is a relationship between the disposition of fluoride in various soft tissues of rats and guinea pigs and the levels of calcium and phosphorous in the tissues. The results suggest that when rats receive a stock corn diet there is a
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New data for the validation of the mean daily maximum permissible concentration of hydrogen fluoride in atmospheric air
1. Round-the-clock exposure to hydrogen fluoride concentrations of 0.10 and 0.03 mg/m3 causes inhibition in the central nervous system, decreases the activity of a number of enzymes, impairs the phosphorus-calcium metabolism, and causes the accumulation of fluorine in the body and damage to the internal organs and bone tissue. 2. A
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Calcium neutralizes fluoride bioavailability in a lethal model of fluoride poisoning.
OBJECTIVES: Acute systemic fluoride poisoning can result in systemic hypocalcemia, cardiac dysrhythmias, and cardiovascular collapse. Topical and intraarterial therapy with calcium or magnesium salts reduces dermal injury from fluoride burns. The mechanism of these therapies is to bind and inactivate the fluoride ion. The purpose of this study is to
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Electrocardiographic studies of the inhabitants in high fluoride districts
1) In the Aso-volcano district, a higher incidence of myocardial damage based on electrocardiographic studies was found in inhabitants of high fluoride communities than in "nonfluoride" villages. 2) In subjects with mottled teeth, greater myocardial damage was encountered electrocardiographically than in persons without mottling in the Asovolcano district. 3) The authors conclude
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Influence of supplementary vitamins and minerals on lipid peroxidation and redox state in heart, kidney and liver of rats exposed to fluoride.
The effect of fluoride (F) and supplementary vitamins and minerals on lipid peroxidation (LPO) and redox state (RS) in heart , kidney and liver of 40 (4 groups of 10) male Wistar rats were studied. One group of rats was left untreated as control, group 1 was received 5 mg/l
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Fluoride & Arterial Calcification
The major change involved with cardiovascular disease is development of atherosclerosis in critical arteries, which is partially characterized by vascular calcification. The level of coronary artery calcification is thought to be the most important indicator of future cardiovascular events. Increased arterial calcifications have frequently been reported in those with skeletal fluorosis
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Fluoride & Electrocardiogram Abnormalities
An electrocardiogram (ECG) is a diagnostic test that measures the electrical activity of the heart. An ECG can reveal heart rate, heart rhythym (i.e. steady or irregular), and the strength and timing of the heart’s natural electrical signals. ECGs are described in terms of “waves” (e.g. amplitude and duration). Problems
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Fluoride & Arteriosclerosis
Healthy arteries are flexible and elastic, allowing efficient transfer of blood and nutrients from the heart to the rest of the body. Arteriosclerosis refers to a stiffening of the arteries, including loss of elasticity. This is a slow, progressive disease that may begin early in life from damage to the
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Fluoride, Blood Pressure and Hypertension
Individuals with blood pressure readings that exceed 140/90 are considered hypertensive. Hypertension can increase the risk of stroke, heart attack, heart failure, aortic aneurysms, and peripheral arterial disease. An association between increased fluoride in ground water and increased prevalence of hypertension has been observed, especially among adult males (Amini et
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Fluoride & Myocardial Damage
Structural damage to the heart resulting from fluoride toxicity has been observed in numerous human and animal studies. The general features of this damage include cloudy swelling, vacuolization or vacuolar degeneration, hemorrhages, interstitial edema, fibrous necrosis, dissolution of nuclei, and thickening of the vessel walls in the heart muscle (Basha
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