Effect of High Fluoride Intake on Haematological Aspects of the Mouse

Abstract

The effect of feeding adult Swiss albino mice of both sexes a diet supplemented with 0, 125, 250 and 500 parts/106 of fluoride for four and eight week periods on haemoglobin concentration (Hb), packed cell volume (PCV) and mean corpuscular haemoglobin concentration (MCHC) was investigated. Values of the three parameters were significantly lowered at both periods in the treated groups as compared with the controls. The extent of reduction in these values was, in general, dependent on the dose of supplemented dietary fluoride. Clinical symptoms were not observed before the end of the sixth week. However, appearance of the symptoms did not change the trend of variations in Hb, PCV and MCHC values. The reduced values could be the result of lowered haemoglobin synthesis and erythropoiesis. It was suggested that these haematological indices could serve to detect preclinical effects of high fluoride intake with an added dose of as low as 125 parts/106, or even less, for a period of four weeks or probably earlier.There have been many studies of the adverse effects of high fluoride intake on bones and teeth of man and animals [Velu, 1932;MacIntire, Winterberg, Clements and Dunham, 1947; Neeley and Harbaugh, 1954;Merriman, Moorman and Hobbs, 1956;Brown, Christofferson, Massler and Weiss, 1960;Johnson, 1965;Shupe, 1969;Bhussry, 1970;McClure, 1970;Jones, 1972;Rosenquist and Lemperg, 1974;Yamamoto, Wergedal and Baylink, 1974;Gileva, Plotko and Gatiyatullina, 1975;Lough, Noonan, Gagnon and Kayne, 1975]. Other tissues, however, as possible affected sites have received less attention. Research reports describing the effects of high levels of fluoride on the blood picture and haematopoietic system are not so frequently encountered.Hoogstratten, Leone, Shupe, Greenwood and Liberman [1965] reported an increase in blood and bone marrow eosinophils and a decrease in serum folic acid activity of cattle received a fluoride-supplemented ration for a period of seven and a half years. The daily ingested level of fluoride was 93 parts/106.Decreased blood levels of copper and calcium, as well as lowered values of packed cell volume (PCV), were observed in sheep grazing, for not less than two years, on pasture contaminated with rock phosphate dust containing 2-1-3-3 % of fluoride emitted from a fertilizer factory [Zumpt, 1975]. The concentration of fluoride in the grazed forage, on a dry matter basis, was 232 parts/106. The effect of a high level of fluoride on some haematological aspects of the rat was investigated by Kahl, Wojcik and Ewy [1973]. Sodium fluoride at a concentration of 150 parts/106 in drinking water lowered, after 75 days, the erythrocyte count and haemoglobin concentration (Hb) down to 20-2 % and 4.5 % of those of the controls, respectively. Decreased incorporation of 59Fe into red blood cells and spleen was also observed along with increased 59Fe incorporation into liver and bone marrow.

Role of Selenium in Alteration of Erythrocyte Parameters in Bovine Fluorosis

“…However, appearance of the symptoms in selenium exposed cattle did change the trend in the above values. In accordance with our findings, Susheela et al (1983) and Mehdi et al (1978) reported on the influence of erythrocyte parameters and showed similar decremental changes in rabbit and mouse. Being a cumulative poison, fluoride induces many metabolic disturbances in different organs, blood being the primary target , with bone and teeth being the second deposition site (McDowell, 1992).…”

“…Bober et al (2001) also found in humans that fluoride caused a decrease in Na + -H + exchanger activity and an increase in intracellular H + ion concentration. Mehdi et al (1978) suggested from mouse studies that hemoglobin, packed cell volume and mean corpuscular hemoglobin concentration values could serve to detect preclinical effects of high fluoride intake with an added dose of as low as 125 mg/kg, or even less, for a period of four weeks or probably earlier. Han et al (2002 reported from cattle studies that fluoride caused a decreased erythrocyte activity of superoxide dismutase, glutathione peroxidase and catalase and an increased content of free radicals and malonaldehyde during long-term intake of an overdose of fluoride.…”

Cytotoxicity of fluoride

“…Acute (one or a few large doses) ( 72) Biochemical and cytological effects (15, 38, 85,103) The mechanism(s) for some of the toxic effects of fluoride are known, e.g. the neuromuscular effects (spasms) are caused by fluoride binding to Ca+ -I-in plasma and thereby lowering the Ca+ -Iconcentration (1 1 , 1 10).…”

Fluoride’s Effects on the Formation of Teeth and Bones, and the Influence of Genetics

“…Effects vary depending upon fluoride dose, duration of exposure, and species, and include anemia and leukopenia (Mehdi et al, 1978;Eren et al, 2005). At modest in vitro concentrations (< 500 μM), NaF has been shown to promote the differentiation of human promyelocytic tumor cells (HL-60) to granulocyte-like cells (Kawase et al, 1996).…”