Abstract
Sodium fluoride (NaF) is widely used for the prevention of dental caries at various concentrations. The clastogenic effect of NaF has been tested by the use of several cytogenetic assay systems, but the findings on its genotoxicity are not consistent. In this study, the effects of NaF on chromosomes, unscheduled DNA synthesis (UDS) and sister-chromatid exchanges (SCEs) were investigated using cultured human lymphocytes. For clastogenicity testing, cells were treated for 24 h in various concentrations of NaF. At least two donors were tested for each concentration and more than 10,000 cells were totally observed. The frequencies of chromosome aberrations were 0.78 + 0.72, 0.88 + 0.56, 0.77 + 0.45, 5.95 + 5.35, 57.76 + 31.46, 108.00 + 59.40, 80.00 + 53.70 and 40.00 + 5.66 per 100 cells for concentrations of 0, 0.25, 0.5, 1.0, 2.0, 4.0, 6.0 and 8.0 mM, respectively. Considerable differences among individuals were observed, but there was no significant difference between sexes. Sodium fluoride treatment had remarkable effects on the induction of isochromatid gaps and chromosome breaks (NUpds). At various concentrations of NaF ranging from 1.0 to 4.0 mM, no increase in UDS and SCE was observed.
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Ameliorative effects of N-acetylcysteine on fluoride-induced oxidative stress and DNA damage in male rats' testis
This study was to elucidate DNA damage in rats treated with sodium fluoride (NaF) by performing 8-Hydroxy-2-deoxyguanosine (8-OHdG) immunohistochemical staining assays on seminiferous tubules of rats' testis, and also to evaluate the protective effects of N-acetylcysteine (NAC) on spermatogenesis. Male Sprague Dawley (SD) rats were exposed to a single dose
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Cytogenetic studies of sodium fluoride in mice
The cytogenetic effects of sodium fluoride (NaF) were measured in mice following administration in the drinking water for 6 weeks. Bone fluoride levels were determined and showed a dose-related incorporation of fluoride. Micronuclei were measured in peripheral blood erythrocytes following 1 and 6 weeks of NaF administration. Bone marrow cell
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Extrapolation from in vitro tests to human risk: experience with sodium fluoride clastogenicity
Genotoxic effects observed in vitro, only at high doses or high levels of cytotoxicity, will be false positives if such conditions are not achieved or cannot be tolerated in vivo. However, for such effects to be disregarded there must be a threshold dose or level of cytotoxicity below which genotoxicity
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DNA damage induced by fluoride in rat osteoblasts
A study is reported of DNA damage by fluoride to primary calvarial osteoblasts of newborn rats isolated by enzymic digestion. Sodium fluoride at concentrations of 0, 0.5, 1, 2, and 3 mmol/L was administered to the isolated osteoblast cells for 24 hr, and damage to DNA was determined by single
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Effect of static magnetic field on the induction of micronuclei by some mutagens
OBJECTIVES: It is important to assess the risk of static magnetic fields (SMFs) on human health, because epidemiological studies have indicated that SMFs play a role in the development of diseases such as leukemia and brain tumor. In our environment, we have numerous chances to be exposed to not only
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Fluoride's Mutagenicity: The "Oral Health Research Institute's" Studies
Although many in vitro and in vivo studies have detected mutagenic effects from fluoride exposure, the Oral Health Research Institute at Indiana University's School of Dentistry has repeatedly failed to find any such effect in multiple studies on the subject.
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Micronucleus and Sister Chromatid Exchange Frequency in Endemic Fluorosis
The rise of sister chromatid exchange (SCE) and micronucleus (MN) in the peripheral blood lymphocytes of the fluorine-intoxicated patients indicates that fluorine is a mutagenic agent which can cause DNA and chromosomal damage.
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Fluoride/Osteosarcoma Link Is Biologically Plausible
The "biological plausiblility" of a fluoride-osteosarcoma link is widely acknowledged in the scientific literature. The biological plausibility centers around three facts: 1) Bone is the principal site of fluoride accumulation, particularly during the growth spurts of childhood; 2) Fluoride is a mutagen when present at sufficient concentrations, and 3) Fluoride can stimulate the proliferation of osteoblasts (bone-forming cells).
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NTP Bioassay on Fluoride/Cancer (1990)
In 1977, the U.S. Congress requested that animal studies be conducted to determine if fluoride can cause cancer. The result of the Congressional request was an extensive animal study conducted in the 1980s by the National Toxicology Program (NTP) and published in 1990. The main finding of NTP's study was a dose-dependent increase in osteosarcoma (bone cancer) among the fluoride-treated male rats.
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Fluoride's Mutagenicity: In vivo Studies
Consistent with dozens of in vitro studies, a number of in vivo studies, in both humans and animals, have found evidence of fluoride-induced genetic damage. In particular, research on humans exposed to high levels of fluoride have found increased levels of "sister chromatid exchange" (SCE). As noted in one study: "In
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