Abstract

This study was conducted to test the hypothesis that physiological changes which occur during aging increase the biological impact of fluoride and reduce the threshold of safe fluoride exposure. Four groups of rats were fed a low-fluoride diet (< 1.2 ppm) ad libitum and received 0, 5, 15, or 50 ppm fluoride in their drinking water. Animals were killed after three, six, 12, or 18 months of treatment. Blood and urine were monitored for biochemical markers of tissue function, and plasma, urine, feces, and representative tissues were analyzed for fluoride. In addition, bone marrow cells from animals killed after 18 months of treatment were examined for frequency of sister chromatid exchange (SCE), a marker of genetic damage. Study results indicated that, within treatment groups, fluoride intake, excretion, and retention did not change significantly between three and 18 months. Fluoride concentration in soft tissues did not change with treatment duration in the fluoride-treated animals. Mineralized tissue fluoride concentration and the total fluoride in the carcasses increased continually as the animals aged. In spite of significant, dose-related differences in tissue fluoride levels which occurred in all age groups in this study, there were no indications that increased fluoride in the tissues caused any adverse physiological or genotoxic effects. None of the monitored clinical “wellness” markers of tissue integrity and function was altered by fluoride in a clinically significant manner. Therefore, there was no evidence from this study that aging reduces the threshold of safe chronic fluoride exposure.

• Related Studies :

  • A quantitative analysis of chronic exposure of selected heavy metals in a model diet in a CKD hotspot in Sri Lanka.

    Background Evidence of chronic low levels of exposure to heavy metals in Sri Lanka has emerged in a number of studies carried out in the recent past. The source and magnitude of such exposures have to be understood in order to assess the risk of adverse health effects of this exposure

  • Evaluation of the toxicity of fluorine in Antarctic krill on soft tissues of Wistar rats

    Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine (F). In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. There were three experimental groups: The control group were fed a basal diet,

  • The potential risks of chronic fluoride exposure on nephrotoxic via altering glucolipid metabolism and activating autophagy and apoptosis in ducks.

    Fluoride is one of the most widely distributed elements in nature, while some fluorine-containing compounds are toxic to several vertebrates at certain levels. The current study was performed to evaluate the nephrotoxic effects of fluoride exposure in ducks. The results showed that the renal index was decreased in NaF group,

  • 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

  • Epigallocatechin gallate supplementation protects against renal injury induced by fluoride intoxication in rats: Role of Nrf2/HO-1 signaling

    Fluoride intoxication generates free radicals, causing oxidative stress that plays a critical role in the progression of nephropathy. In the present study, we hypothesized that epigallocatechin gallate (EGCG), found in green tea, protects the kidneys of rats treated with fluoride by preventing oxidative stress, inflammation, and apoptosis. Pretreatment of fluoride-treated

• Related FAN Content :

  • Kidney: A potential target for fluoride toxicity

    The kidneys are the organ responsible for clearing fluoride from the body. In the process of doing so, the kidneys are exposed to concentrations of fluoride that exceed, by a factor of 50, the concentration of fluoride in human blood. As such, the kidney have long been considered a potential

  • Fluoride Gels & Kidney Function

    Scientists have found that the application of "Fluoride Gels" at the dental office causes very high spikes in the blood fluoride level. The high spikes in blood fluoride levels are a result of three factors: the high concentration of fluoride in the gel (= 12.3 mg of fluoride in each

  • Fluoride & Kidney Stones

    It has long been suspected that fluoride may contribute to the formation of kidney stones. This suspicion has recently gained support from a study of an American man with skeletal fluorosis. According to the authors: "A new, important, medical problem (that seemed temporally related to cessation of fluoride exposure and subsequent negative calcium

  • Fluoridation of drinking water and chronic kidney disease: Absence of evidence is not evidence of absence

    A fairly substantial body of research indicates that patients with chronic renal insufficiency are at an increased risk of chronic fluoride toxicity. Patients with reduced glomerular filtration rates have a decreased ability to excrete fluoride in the urine. These patients may develop skeletal fluorosis even at 1 ppm fluoride in the drinking water.

  • Fluoride as a Cause of Kidney Disease in Animals

    Because the kidney is exposed to higher concentrations of fluoride than all other soft tissues (with the exception of the pineal gland), there is concern that excess fluoride exposure may contribute to kidney disease - thus initiating a "vicious cycle" where the damaged kidneys increase the accumulation of fluoride, causing in