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Li H, Fan J, Zhao Y, Yang J, Xu H, Manthari RK, Cheng X, Wang J, Wang J. Calcium alleviates fluoride-induced kidney damage via FAS/FASL, TNFR/TNF, DR5/TRAIL pathways in rats. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 226:112851. [PMID: 34619480 DOI: 10.1016/j.ecoenv.2021.112851] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
Long-term excessive intake of fluoride (F) can cause osseous and non-osseous damage. The kidney is the main fluoride excretion organ of the body. This study aimed to explore whether dietary calcium (Ca) supplementation can alleviate kidney damage caused by fluorosis and to further investigate the effects of Ca on the mitigation mechanism of renal cell apoptosis triggered by F. We evaluated the histopathological structure, renal function indicators, and gene and protein expression levels of death receptor-mediated apoptosis pathways in Sprague Dawley (SD) rats treated with sodium fluoride (NaF) and/or calcium carbonate (CaCO3) for 120 days. The results showed that 100 mg/L NaF induced kidney histopathological injury and apoptosis, increased the concentrations of Creatinine (CRE), uric acid (UA), blood urea nitrogen (BUN), potassium (K), phosphorus (P) and F (p < 0.05), and decrease the level of serum magnesium (Mg) (p < 0.05). Moreover, NaF increased the mRNA and protein expression levels of Fas cell surface death receptor (FAS), tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), Caspase 8, Caspase 3 and poly ADP-ribose polymerase (PARP) (p < 0.01), which finally activated the death receptor pathway. Inversely, Ca supplementation reversed the decrease of CRE, BUN, UA, F and P levels induced by F, alleviated histopathological damage and apoptosis, and reduced the gene and protein expression levels of death receptor pathway-related markers. In conclusion, 1% Ca alleviates F-induced kidney apoptosis through FAS/FASL, TNFR/TNF, DR5/TRAIL signaling pathways.
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Affiliation(s)
- Haojie Li
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Junjiang Fan
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Yangfei Zhao
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Jiarong Yang
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Huimiao Xu
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Ram Kumar Manthari
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Xiaofang Cheng
- Department of Basic Science, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Jundong Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China
| | - Jinming Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China; Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, Shanxi, PR China.
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Lyaruu DM, Vermeulen L, Stienen N, Bervoets TJM, Denbesten PK, Bronckers ALJJ. Enamel pits in hamster molars, formed by a single high fluoride dose, are associated with a perturbation of transitional stage ameloblasts. Caries Res 2012; 46:575-80. [PMID: 22947666 DOI: 10.1159/000341802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 06/29/2012] [Indexed: 11/19/2022] Open
Abstract
Excessive intake of fluoride (F) by young children results in the formation of enamel subsurface porosities and pits, called enamel fluorosis. In this study, we used a single high dose of F administered to hamster pups to determine the stage of ameloblasts most affected by F and whether pit formation was related to F-related sub-ameloblastic cyst formation. Hamster pups received a single subcutaneous injection of either 20 mg or 40 mg NaF/kg body weight, were sacrificed 24 h later, and the number of cysts formed in the first molars were counted. Other pups were sacrificed 8 days after F injection, when the first molars had just erupted, to score for enamel defects. All F-injected pups formed enamel defects in the upper half of the cusps in a dose-dependent way. After injection of 20 mg NaF/kg, an average of 2.5 white spots per molar was found but no pits. At 40 mg NaF/kg, almost 4.5 spots per molar were counted as well as 2 pits per molar. The defects in erupted enamel were located in the upper half of the cusps, sites where cysts had formed at the transition stage of ameloblast differentiation. These results suggest that transitional ameloblasts, located between secretory- and maturation-stage ameloblasts, are most sensitive to the effects of a single high dose of F. F-induced cysts formed earlier at the pre-secretory stage were not correlated to either white spots or enamel pits, suggesting that damaged ameloblasts overlying a F-induced cyst regenerate and continue to form enamel.
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Affiliation(s)
- D M Lyaruu
- Department of Oral Cell Biology, ACTA, University of Amsterdam and VU University of Amsterdam, MOVE-Research Institute, Amsterdam, The Netherlands
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3
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Bronckers ALJJ, Lyaruu DM, DenBesten PK. The impact of fluoride on ameloblasts and the mechanisms of enamel fluorosis. J Dent Res 2009; 88:877-93. [PMID: 19783795 DOI: 10.1177/0022034509343280] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Intake of excess amounts of fluoride during tooth development cause enamel fluorosis, a developmental disturbance that makes enamel more porous. In mild fluorosis, there are white opaque striations across the enamel surface, whereas in more severe cases, the porous regions increase in size, with enamel pitting, and secondary discoloration of the enamel surface. The effects of fluoride on enamel formation suggest that fluoride affects the enamel-forming cells, the ameloblasts. Studies investigating the effects of fluoride on ameloblasts and the mechanisms of fluorosis are based on in vitro cultures as well as animal models. The use of these model systems requires a biologically relevant fluoride dose, and must be carefully interpreted in relation to human tooth formation. Based on these studies, we propose that fluoride can directly affect the ameloblasts, particularly at high fluoride levels, while at lower fluoride levels, the ameloblasts may respond to local effects of fluoride on the mineralizing matrix. A new working model is presented, focused on the assumption that fluoride increases the rate of mineral formation, resulting in a greater release of protons into the forming enamel matrix.
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Affiliation(s)
- A L J J Bronckers
- Department of Oral Cell Biology, ACTA, University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Amsterdam, The Netherlands
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4
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Lyaruu DM, Blijleven N, Hoeben-Schornagel K, Bronckers AL, Wöltgens JH. X-ray micro-analysis of the mineralization patterns in developing enamel in hamster tooth germs exposed to fluoride in vitro during the secretory phase of amelogenesis. Adv Dent Res 1989; 3:211-8. [PMID: 2640432 DOI: 10.1177/08959374890030022201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The developing enamel from three-day-old hamster first maxillary (M1) molar tooth germs exposed to fluoride (F-) in vitro was analyzed for its mineral content by means of the energy-dispersive x-ray microanalysis technique. The aim of this study was to obtain semi-quantitative data on the F(-)-induced hypermineralization patterns in the enamel and to confirm that the increase in electron density observed in micrographs of F(-)-treated enamel (Lyaruu et. al., 1986, 1987b) is indeed due to an increase in mineral content in the fluorotic enamel. The tooth germs were explanted during the early stages of secretory amelogenesis and initially cultured for 24 hr in the presence of 10 ppm F- in the culture medium. The germs were then cultured for another 24 hr without F-. In order to compare the ultrastructural results directly with the microprobe data, we used the same specimens for both investigations. The net calcium counts (measurement minus background counts) in the analyses were used as a measure of the mineral content in the enamel. The aprismatic pre-exposure enamel, deposited in vivo before the onset of culture, was the most hypermineralized region in the fluorotic enamel, i.e., it contained the highest amount of calcium measured. The degree of the F(-)-induced hypermineralization gradually decreased (but was not abolished) in the more mature regions of the enamel. The unmineralized enamel matrix secreted during the initial F- treatment in vitro mineralized during the subsequent culture without F-. The calcium content in this enamel layer was in the same order of magnitude as that recorded for the newly deposited enamel in control tooth germs cultured without F-.(ABSTRACT TRUNCATED AT 250 WORDS)
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5
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Larsen MJ, Kirkegaard E, Poulsen S, Fejerskov O. Dental fluorosis among participants in a non-supervised fluoride tablet program. Community Dent Oral Epidemiol 1989; 17:204-6. [PMID: 2788065 DOI: 10.1111/j.1600-0528.1989.tb00612.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The aim of the present study was to describe the intraoral pattern of dental fluorosis among fluoride tablet consumers. One hundred and forty-two children, of whom 56 had participated in a fluoride tablet program of 0.5/1.0 mg NaF per day were examined blindly for possible fluoride-induced enamel changes. A low prevalence of dental fluorosis was found among non-participants. The later in life the tooth was formed, the higher was the prevalence. The subjects who had participated in the fluoride tablet program showed a significantly higher prevalence of fluorosis. They could be divided into three groups: Group 1 exhibited a tooth prevalence pattern not statistically different from that of the non-participants, group 2 showed dental fluorosis in almost all teeth except in those formed before the start of the tablet program. In group 3 the early and the late formed teeth showed very little fluorosis while those formed in the few years just after the initiation of the fluoride tablet intake were affected by fluorosis.
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Affiliation(s)
- M J Larsen
- Department of Oral Anatomy, Royal Dental College, Aarhus, Denmark
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6
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Fujii A, Tamura T. Deleterious effect of sodium fluoride on gastrointestinal tract. GENERAL PHARMACOLOGY 1989; 20:705-10. [PMID: 2606338 DOI: 10.1016/0306-3623(89)90111-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. The effect of sodium fluoride (NaF) on gastrointestinal tracts of rats was investigated. 2. Blood flow rate in rat stomach mucosa was only 30% of the initial rate during 30-60 min after a single oral dose (300 mg/kg) of NaF. 3. The addition of NaF (final NaF concentration: 50 and 100 ppm) in vitro gave the reduction of 10 and 28%, respectively, of initial free calcium ion levels in rat blood. 4. These results indicate that oral ingestion of excess amount of NaF caused dilatation of blood vessel and greatly decreased blood flow rate to accumulate the circulating blood in the mucosa of gastrointestinal tract to cause redness.
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Affiliation(s)
- A Fujii
- Department of Pharmacology, Nihon University School of Dentistry, Chiba, Japan
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7
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Bronckers AL, Bervoets TJ, Lyaruu DM, Wöltgens JH. Antagonism of fluoride toxicity by high levels of calcium but not of inorganic phosphate during secretory amelogenesis in the hamster tooth germ in vitro. Arch Oral Biol 1989; 34:625-36. [PMID: 2597052 DOI: 10.1016/0003-9969(89)90017-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Whether the interference by fluoride (F-) with secretory amelogenesis in vitro could be modulated by altering the levels of calcium (Ca) and inorganic phosphate (P) in the medium was investigated. Hamster first upper molar tooth germs in the secretory phase of amelogenesis were exposed to 10 microM-1.31 mM (0.2-25 parts/10(6)) of F- in vitro for 2 days in the presence of either low (1.2 mM), moderate (2.1 mM) or high (4.1 mM) levels of Ca, or moderate (1.6 mM) and high (3.6 mM) levels of P. The biosynthesis and secretion of enamel matrix proteins under each of the experimental conditions were examined by labelling with [3H]-proline during the last 24 h of culture, and mineralization by labelling with 45Ca and [32P]-orthophosphate. With moderate levels of Ca and P (control medium), F- increased the uptake of 45Ca and 32P in a dose-dependent manner; F- did not inhibit the synthesis of matrix proteins but to a moderate extent impaired their secretion. In explants grown in the presence of 52 microM of F- the superficial layers of enamel matrix deposited in vitro (fluorotic matrix) failed to mineralize. Increasing P levels in the medium had no clear histological effect, whereas lowering Ca levels sometimes seemed to aggravate the F- effect. Raising Ca levels improved the histological pattern: in spite of the presence of F-, high Ca levels allowed a limited mineralization of the superficial layer of fluorotic matrix along with a strong rise in mineralization of the deeper layers of pre-exposure enamel. High Ca levels also considerably reduced the cellular changes in secretory ameloblasts induced by 52 microM of F- and slightly counteracted the inhibition of matrix secretion, as measured biochemically. Some of the effects of F- on secretory amelogenesis in vitro can thus be reversed by raising Ca levels in the medium. Therefore, the effect of F- on secretory amelogenesis in vitro seems to be primarily interference with the enamel mineralization process per se and, secondarily, an impairment of matrix secretion.
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Affiliation(s)
- A L Bronckers
- Department of Oral Cell Biology, ACTA, Vrije Universiteit, Amsterdam, The Netherlands
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8
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Jones HC, Keep RF. Brain fluid calcium concentration and response to acute hypercalcaemia during development in the rat. J Physiol 1988; 402:579-93. [PMID: 3236250 PMCID: PMC1191910 DOI: 10.1113/jphysiol.1988.sp017223] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
1. In vivo measurements of plasma, cerebrospinal fluid (CSF) and brain interstitial fluid (ISF) ionic Ca2+ concentrations ([Ca2+]) have been made in anaesthetized rats aged between 19 days gestation and adult using calcium-selective microelectrodes. Total calcium concentration ([ Ca]) has also been determined in plasma and CSF samples by atomic absorption spectrometry. 2. Under control conditions, plasma, CSF and ISF [Ca2+] showed a small, but significant, decrease with age. Plasma and CSF, but not ISF, showed a transient hypocalcaemia at birth. After birth there were no significant differences between plasma, CSF and ISF [Ca2+], except in adult rats where CSF [Ca2+] was significantly lower than plasma [Ca2+]. The age-related changes in CSF and ISF [Ca2+] were small and it is uncertain as to whether they may have any functional significance. 3. Under control conditions, plasma and CSF [Ca] also declined with age. The fall in plasma [Ca] paralleled the changes in plasma [Ca2+]. The decrease in CSF [Ca] was steeper than that in [Ca2+] and indicated a higher proportion of protein-bound or complexed calcium in the CSF of young when compared to old rats. 4. Acute plasma hypercalcaemia was induced by intramuscular injections of calcium gluconate and consequent changes in CSF or ISF [Ca2+] were monitored in vivo. There was very weak regulation of CSF and ISF [Ca2+] at 21 days gestation, which may reflect placental control over fetal plasma calcium. Soon after birth there was good regulation in both ISF and CSF [Ca2+]. CSF [Ca] was also measured during hypercalcaemia in samples from post-natal rats and there was similar regulation to that in CSF [Ca2+]. 5. It is concluded that under control conditions, during rat development, CSF and ISF [Ca2+] closely follow changes in plasma [Ca2+], but that soon after birth homeostatic mechanisms develop to prevent large fluctuations in brain fluid calcium.
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Affiliation(s)
- H C Jones
- Department of Zoology, University of Hull
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9
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Monsour PA, Smid JR, Kruger BJ. The effect of intravenous sodium fluoride and synthetic salmon calcitonin on plasma total calcium, inorganic phosphate, and ionic fluoride. Calcif Tissue Int 1987; 41:105-11. [PMID: 3115544 DOI: 10.1007/bf02555252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Various doses of sodium fluoride (NaF), salmon calcitonin (CT) and NaF combined with CT were given intravenously to rats (236 +/- 2 g). Blood plasma samples were collected at various times up to 24 hours and measured for total calcium (adjusted for variation in plasma albumin), inorganic phosphate, ionic fluoride, urea, and creatinine. Following injection of NaF alone, significant hypocalcemia and hyperphosphatemia was observed. In contrast, CT injections resulted in hypocalcemia and hypophosphatemia. NaF and CT given in combination generally resulted in the hypocalcemia being equal to or greater than that calculated from the simple addition of their individual effects. Significant increases in both plasma creatinine and plasma urea were observed following treatment with NaF alone or with CT and NaF together, whereas CT alone had negligible effect. These results suggest that NaF does not mimic the effects of CT; rather that NaF and CT interact to modify their individual effects. The influence of NaF probably occurs via an effect on kidney function.
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Affiliation(s)
- P A Monsour
- Department of Oral Biology and Oral Surgery, University of Queensland, St. Lucia, Australia
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10
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Larsen MJ, Kirkegaard E, Poulsen S. Patterns of dental fluorosis in a European country in relation to the fluoride concentration of drinking water. J Dent Res 1987; 66:10-2. [PMID: 3476536 DOI: 10.1177/00220345870660010101] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Dental fluorosis among 456 14-16-year-old schoolchildren who had resided continuously since birth in their respective study areas was recorded using the Thylstrup and Fejerskov classification system. The children fell into four groups according to fluoride concentration of their drinking water: (1) less than or equal to 0.1 ppm; (2) 0.3-0.5 ppm; (3) 0.5-1.25 ppm; and (4) 1.26-2.0 ppm. It was found that the later in childhood the tooth was formed, the higher was the prevalence of dental fluorosis. The fluoride concentration in the drinking water affected the prevalence of dental fluorosis in all teeth except the lower incisors, which are formed very early in life. Apart from these teeth, the proportionate increase of dental fluorosis with increasing water fluoride concentration was almost the same for all tooth types. However, the actual amount of increase in the prevalence and degree of fluorosis was greatest among those teeth that formed later during childhood. The observed fluorosis is presumed to result from and reflect the drinking water habits in the population as well as the patterns of use of fluoride prophylactics.
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Simmelink JW, Lange A. Ultrastructure of altered rat enamel beneath fluoride-induced cysts. JOURNAL OF ORAL PATHOLOGY 1986; 15:155-61. [PMID: 3084740 DOI: 10.1111/j.1600-0714.1986.tb00598.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effect of a single injection of sodium fluoride (60 mg/kg) on the development of rat molar enamel beneath fluoride-induced subameloblastic cysts was studied by transmission electron microscopy using undecalcified sections. Three bands of altered enamel were identified and defined as the cyst surface band, the hypoplastic band, and the hypercalcified band. The irregular cyst surface band, not previously described, was found to have two components: electron-dense enamel globules and organic spherules. The electron-dense globules consisted of small, randomly arranged crystals (confirmed by selected area electron diffraction) occurring within a stippled organic matrix. The organic spherules have staining properties similar to stippled material and lack a crystalline component. They may be a form of organic material being extruded from the underlying developing enamel. The critical role of normal matrix production and ameloblast Tomes' process structure on the development of the crystal orientation and rod pattern is discussed.
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Nordlund AL, Ekstrand JL, Hammarström L. Fluoride-induced cystic changes in the enamel organ of the rat molar. JOURNAL OF ORAL PATHOLOGY 1986; 15:87-92. [PMID: 3083068 DOI: 10.1111/j.1600-0714.1986.tb00583.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Many substances have been found to cause enamel disturbances in toxic doses, and it has been postulated that these disturbances are linked to the formation of sub-ameloblastic cysts. In the present investigation, fluoride-induced sub-ameloblastic cysts in developing rat molars were related to fluoride dose, age of the animals, and the plasma fluoride level. The sub-ameloblastic cysts, which developed predominantly towards the end of the secretory stage of amelogenesis, appeared shortly after fluoride administration and regressed within 3 days. Hypoplasias and internal defects were found in the enamel under the disturbed ameloblast layer. The highest plasma fluoride levels were found in the youngest animals 24 h after injection. The frequency and size of the sub-ameloblastic cysts were clearly related to the fluoride-dose and age of the animal and, subsequently, to the plasma fluoride level.
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Monsour PA, Kruger BJ, Smid JR. Effects of a single intravenous dose of sodium fluoride on plasma electrolytes and metabolites in rats, rabbits, and cockerels. J Dent Res 1985; 64:1281-5. [PMID: 3867685 DOI: 10.1177/00220345850640110501] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
This study assessed the effect of a single intravenous dose of sodium fluoride (20 mg/kg body wt.) on plasma ionic fluoride and on some other plasma electrolytes and metabolites in rats, rabbits, and cockerels. At any given time following sodium fluoride administration, the plasma ionic fluoride was highest in rabbits and lowest in cockerels. The rate of removal of fluoride from plasma was slower in rabbits as compared with that in the other two species. Plasma sodium, chloride, total protein, albumin, total globulins, and osmolality were not significantly altered by sodium fluoride in any of these three species. However, plasma phosphate (inorganic), urea, creatinine, and glucose were elevated, and plasma calcium was reduced in the rats and the rabbits, but none was significantly altered in the cockerels. The analyses indicated that species variability does exist in fluoride toxicity.
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14
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Bronckers AL, Wöltgens JH. Short-term effects of fluoride on biosynthesis of enamel-matrix proteins and dentine collagens and on mineralization during hamster tooth-germ development in organ culture. Arch Oral Biol 1985; 30:181-91. [PMID: 3857037 DOI: 10.1016/0003-9969(85)90113-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of various concentrations of fluoride (F-) on cell proliferation, matrix formation and mineralization was examined in hamster molar tooth germs in premineralizing and mineralizing stages. The exposure lasted 16 h (mineralizing stages) and 24 h (premineralizing stages) and the F- levels ranged from 2.63 microM to 2.63 mM; [3H]-thymidine, [3H]-proline, 45Ca and 32PO4 were used as markers for cell proliferation, matrix formation and mineralization, respectively. The proline-labelled amelogenins were isolated by sequential extraction with water and formic acid and their nature examined by SDS-urea-polyacrylamide electrophoresis. Digestion by collagenase was used to assess the amount of proline incorporated into collagens. F- in concentrations up to 1.31 mM inhibited neither biosynthesis of DNA and amelogenins, nor synthesis of collagens and their hydroxylation. Amelogenins extracted from F- induced, non-mineralizing enamel matrix had the same electrophoretic mobility and the same degree of phosphorylation as amelogenins from normal, mineralizing enamel. However, F- increased the uptake of 45Ca and TCA-soluble 32P dose-dependently, starting with 52 microM. Thus, interference with secretion of enamel matrix by F- takes place at much lower concentrations than required to inhibit biosynthesis of enamel matrix.
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15
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Soni MG, Pawar SS. Effect of sodium fluoride on hepatic microsomal mixed-function oxidase system in newborn and adult male rats. Toxicol Lett 1984; 21:163-6. [PMID: 6719497 DOI: 10.1016/0378-4274(84)90200-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Administration i.p. of sodium fluoride at 2.5 or 5.0 mg/kg induced the mixed-function oxidase system in both newborn and adult rats; at 10.0 mg/kg there was induction in newborn rats and inhibition in adult rats, and at 20.0 mg/kg, there was inhibition in both newborn and adults.
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16
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Gaugl JF, Wooldridge B. Cardiopulmonary response to sodium fluoride infusion in the dog. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1983; 11:765-82. [PMID: 6312063 DOI: 10.1080/15287398309530383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Because humans are occasionally acutely exposed to high levels of fluoride (F-), and cardiac and especially pulmonary tissue accumulate higher concentrations of F- than do the other soft tissues, the present study was undertaken to investigate the effects of acute exposure to toxic plasma levels of F- on cardiopulmonary hemodynamics. Anesthetized dogs were instrumented with right and left cardiac catheters to measure pulmonary arterial and wedge pressures, left ventricular and aortic pressures, left ventricular dP/dt, and cardiac output. An intravenous loading dose of NaF followed by a 3-h infusion produced a plasma F- level of 800 microM in the "low" group of 6 animals, and 1300 microM in the "high" group. The mean pulmonary arterial pressure peaked at 1 h, 83% above preinfusion values in the high group, while that of the low group attained the same level by the end of the infusion period. Impaired pulmonary gas exchange, as indicated by an increased alveolar-arterial PO2 gradient, occurred in half the animals, and an obvious hyperventilation was reflected in a decreased PCO2 value; there was no change in arterial pH, ECG T-wave peaking was common. The central venous pressure declined steadily, while there were no significant changes from controls in systemic arterial pressure, heart rate, cardiac output, or myocardial contractility (dP/dt). Thus, pulmonary hemodynamics and the systemic capacitance vessels are more affected by acute exposure to F- than is cardiac function.
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