Neurofunctional effects of developmental sodium fluoride exposure in rats

Lucian Blaga University, Medical School, Sibiu, Romania.
European review for medical and pharmacological sciences (Impact Factor: 1.21). 07/2007; 11(4):211-24.
Source: PubMed


Contrasting studies on the toxic effects of sodium fluoride (NaF) during developmental stages of Wistar rats, lead us to investigate the neurofunctional effects caused by its perinatal exposure, devoid of any overt sign of toxicity and/or gross malformation. NaF solution was administered to pregnant rats by intragastric gavage at a daily dose of 2.5 and 5.0 mg/kg from gestational day 0 to day 9 after parturition. Developmental NaF exposure caused sex and dose specific behavioural deficits which affected males more than females in the majority of the evaluated end-points. In particular, the perinatal exposure to NaF 5.0 mg/kg, significantly affected learning, memory, motor coordination and blood pressure only in male rats. Conversely, a lack of habituation upon the second presentation of the objects and failure in the ability to discriminate between the novel and the familiar object were observed only in NaF 5.0 mg/kg female rats. Finally, a significant impairment of sexual behaviour was observed in male rats at both NaF dose levels. The present data indicate that perinatal rat exposure to NaF results in long lasting functional sex-specific alterations which occur at fluoride levels approaching those experienced by offspring of mothers.

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    • "Behavioural studies conducted on the post natal pups aged between day 21 and 30 showed significant changes in motor control and cognition in fluoride treated when compared to the control rats (p<0.05*). From the figure 3 and 4 it is evident that the chronic exposure of fluoride in rats would cause loss of motor control and cognition as a result of oxidative stress induced neurodegeneration (Bera et al., 2007).The figure 5 and 6 shows the biochemical analysis of SOD and LPO levels in whole brain tissue lysates in both control and fluoride treated groups. "
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    ABSTRACT: Fluoride induced oxidative stress through depletion in levels of various anti-oxidants such as glutathione, superoxide dismutase (SOD), fat soluble vitamins (D and E) with increased levels of lipid peroxidation (LPO) and fluoride aggravate the damage in rodents as well as in humans. Vitamins A, a fat soluble vitamin possess antioxidant property which plays a significant role in scavenging the free radicals species similar to vitamin D and E. Vitamin A is involved in neural tissue development and plasticity. The growing evidence about vitamin A being antioxidant in different biological reactions formed the basis to determine the effect of fluoride on its levels. The present study was conducted in Wistar rat pups. The pregnant wistar rats were dosed with 20. ppm sodium fluoride (NaF) from day one of pregnancy till the pups were aged day30. The serum was collected from developing rat pups on regular intervals (14th, 21st, 30th day) and vitamin A levels were analyzed by High performance liquid chromatography (HPLC). Body weights, Behavioural studies and spectrophotometric estimation of SOD, LPO in brain lysates were also performed. The results showed significant decrease (p< 0.001) in vitamin A in fluoride induced samples in comparison to the control samples suggesting that decreased levels of vitamin A can be used as another marker in fluoride induced toxicity studies.
    Full-text · Article · Sep 2015 · International Journal of Developmental Neuroscience
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    • "A decrease in uterine weight and foetus number was recorded in rats orally exposed to NaF (40 mg/kg) during days 6–19 of gestation [14]. In addition, impairment of motor coordination, learning and memory as a result of perinatal exposure to NaF (5 mg/kg) was found to be more marked in male than in female offspring [15]. In spite of all the above-listed studies, literature is poor on the effects on the central nervous system of the exposure to low F doses during pregnancy and lactation. "
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    ABSTRACT: It is known that exposure to high concentrations of Fluoride (F) produces deleterious health effects in human population. However, in the last years it has been concluded that low concentrations of F may have adverse health effects as well. Transplacental passage of F and its incorporation into foetal tissues has been demonstrated. Therefore, the purpose of the present work was to study the effects of the exposure to low levels of F during pregnancy and lactation on the central nervous system functionality. Wistar rats were exposed to low F concentrations (5 and 10 mg/l) during pregnancy and lactation. Sensorimotor reflexes in the each pup were analysed and the postnatal day on which both eyes and auditory canals were opened was recorded. Locomotor activity and anxiety were subsequently analysed in 45- and 90-day-old offspring by an open field test and plus maze test, respectively. A significant delay in the development of eye opening was observed in all offspring whose mothers had been exposed to the two F concentrations tested. Exposure to 5 and 10 mg/l F was also found to significantly decrease locomotor activity only in 90-day-old male and female offspring. A low index of anxiety in the young females and in all adult offspring exposed to the two F concentrations tested was also detected. Taken together, findings from the present study show that exposure to low F concentrations during pregnancy and lactation produces dysfunction in the central nervous system mechanisms which regulate motor and sensitive development, locomotor activity and anxiety.
    Full-text · Article · Apr 2015 · Physiology & Behavior
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    • "Also, the fluoride toxicity on reproductive system may be related with the period of treatment, such as prenatal or pubertal exposures. For example, Bera et al. (2007) observed sexual behavior impairment in descendants male rats exposed to NaF at a dose of 2.5 and 5.0 mg/kg during the critical periods of pregnancy and lactation. "
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    ABSTRACT: The aim of the present study was to evaluate the effects of sodium fluoride (NaF) on the male reproductive system. Adult male rats were exposed to NaF in drinking water for 30 days at three concentrations: 1.54 (control, tap water), 50 and 100 ppm. Body and organ weights, daily sperm production, sperm number and morphology were investigated. No difference was observed on the sperm number and morphology among the groups, as well as body weight and organ absolute and relative weights. Overall, despite the presence of a mild degree of dental fluorosis in the higher dose group, the results indicated that exposure to NaF at the doses used in the present study did not adversely affect sperm production and morphology of male rats.
    Preview · Article · Apr 2012 · Brazilian Archives of Biology and Technology
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