Current quality standards of cattle bile and sheep bile quality standards and discussion on related problems / 中国中药杂志

To analyze quality standards of cattle bile and sheep bile, and to discuss the related problems in the standards. The results showed that physical forms of the related medicinal materials of cattle bile and sheep bile were chaotic, and the technical methods adopted in the quality standards were generally backward. In addition, there were still problems that some medicinal material standards lacked necessary test items, which were especially obvious in the relevant medicinal material standards of sheep bile and brought difficulties to quality evaluation and control. We suggest that physical forms of cattle bile and sheep bile in quality standards should be determined, and inspection items should be completed. Based on mainstream analytical technology, some technical methods of these standards should be improved.

Role of hypoxia-induced VEGF in blood-spinal cord barrier disruption in chronic spinal cord injury / 中华创伤杂志(英文版)

Chronic spinal cord lesions (CSCL) which result in irreversible neurologic deficits remain one of the most devastating clinical problems. Its pathophysiological mechanism has not been fully clarified. As a crucial factor in the outcomes following traumatic spinal cord injury (SCI), the blood-spinal cord barrier (BSCB) disruption is considered as an important pathogenic factor contributing to the neurologic impairment in SCI. Vascular endothelial growth factor (VEGF) is a multirole element in the spinal cord vascular event. On one hand, VEGF administrations can result in rise of BSCB permeability in acute or sub-acute periods and even last for chronic process. On the other hand, VEGF is regarded to be correlated with angiogenesis, neurogenesis and improvement of locomotor ability. Hypoxia inducible factor-1 (HIF-1) is a primary regulator of VEGF during hypoxic conditions. Therefore, hypoxia-mediated up-regulation of VEGF may play multiple roles in the BSCB disruption and react on functional restoration of CSCL. The purpose of this article is to further explore the relationship among HIF-1, hypoxia-mediated VEGF and BSCB dysfunction, and investigate the roles of these elements on CSCL.

Level of reduced glutathione and oxidized glutathione in a mouse bone cell line MC3T3-E1 cells exposed to fluoride / 中国地方病学杂志

Objective To observe the level of reduced glutathione(GSH) and oxidized glutathione(GSSG)in a mouse bone cell line MC3T3-E1 cells exposed to fluoride.Methods MTT method was used to detect cell viability of M C3T3-E1 cells exposed to varying concentrations and periods of fluoride [F-concentration:0(control),0.5,1.0,2.0,4.0,8.0,12.0,20.0 mg/L; F-periods:1,2,4 and 10 days].The Xevo TQ MS was employed to test the levels of GSH,GSSG and glutamine (Gln).Results The MC3T3-E1 cell viability was significantly higher in the 2 mg/L group(0.57 ± 0.05) 1 day after the exposure compared to the respective control(0.49 ± 0.03,P ＜0.01); conversely,cell viability was markedly lower in the 8 mg/L(0.49 ± 0.07) and 12 mg/L(0.47 ± 0.09)groups 4 days after the exposure in comparison to the control(0.63 ± 0.06,P ＜ 0.05 or P ＜ 0.01).The cell viability in the 8 mg/L group(1.52 ± 0.29) 10 days after the exposure was significantly higher than that in the control group (0.86 ± 0.23,P ＜ 0.01),however,the value in the 20.0 mg/L group (0.54 ± 0.07) was significantly lower(P ＜0.01).The level of cell GSH decreased significantly in the 20 mg/L groups 2 days[(13.92 ± 4.63)μmol/L]and 10 days [(0.53 ± 0.30)μmol/L]after exposure compared to the respective comtrols [(26.42 ± 3.67),(24.85 ± 5.68)μmol/L,all P ＜ 0.01].The level of cell GSSG markedly increased in the 2 mg/L group 2 days [(1.12 ± 0.62)μ mol/L]and the 8 mg/L group 4 days [(2.13 ± 0.62)μ mol/L]after exposure compared to the controls[(0.55 ± 0.22),(1.46 ± 0.46)μmol/L,all P ＜ 0.05].The similar change was observed in the 8 mg/L group[(2.97 ± 1.30)μmol/L] 10 days after exposure compared to the control [(1.35 ± 0.50)μmol/L,P ＜ 0.05].The level of Glndecreased significantly in the 2 mg/L group[ (62.80 ± 17.4l)μ mol/L] 4 days and in the 8 and 20 mg/L groups 10 days[ (122.26 ± 19.51), (19.38 ± 8.11)μmol/L] after exposure compared to the controls [ (83.28 ±14.32), ( 147.15± 16.95) μmol/L , all P ＜ 0.05 or P ＜ 0.01 ]. Conclusions Fluoride exposure can significantly promote the changes of GSH, GSSG and Gln levels in the osteoblast, thus affecting the intracellular redox equilibrium.

Effects of fluoride on fibronectin expression of rats osteoblasts / 中国地方病学杂志

Objective To observe the expression of fibronectin in bone of fluorosis rats and in vitro cultured osteoblast,and to study the role of fibronectin in pathogenesis of chronic fluorosis.Methods Male and female Wistar rats 144 were randomly divided into four groups,which were designated as the control group(normal diets,n =36),fluoride group(normal diets + 100 mg/L fluoride,n =36),lower calcium monophagia group (synthetic diets,n =36) and lower calcium monOphagia with fluoride group(synthetic diets + 100 mg/L fluoride,n =36).Rats were sacrificed 4 and 8 months after beginning of the experiment,respectively,and femur tissue was fixated and paraffin-embedded.The osteoblast isolated from calvaria of neonatal rats was treated with different dose of fluoride(0,1,2,4 mg/L fluoride,respectively) for 48 and 72 h,cell culture supernatant and cells were collected,respectively.The cranial osteoblasts were cultured in vitro and divided into four groups according to different concentration of fluoride added,which were 0(control group),0.01,1.00,and 10.00 mg/L groups.These cells were treated with mineralized induced medium at day 2 and cultured for 3 more weeks whereafter,and then the slides were fixed in alcohol.The expression of fibronectin in rat femur tissue was detected by immunohistochemistry (IHC),and fibronectin mRNA expression was determined by in situ hybridization; the fibronectin levels in supernatant of cultured osteoblast was examined by enzyme-linked immunosorbent assay(ELISA),and the expression of fibronectin mRNA in osteoblasts was detected with RT-PCR; skull mineralized nodule formation of osteoblasts was observed under a light microscopy after stained with 0.1％ red alizarin liquid.Results Little expression of fibronectin (brown granules under light microscope) could be seen in femur tissue of fluorosis rats of control group and lower calcium monophagia group; but abundantly expressed in fluoride group and lower calcium monophagia with fluoride group; the fibronectin was also expressed in osteoblasts,bone cells and bone marrow cells with less red particles in the control group and lower calcium monophagia group,but more in the fluoride group and lower calcium monophagia with fluoride group.The expression of fibronectin protein in supernatant of cultured osteoblasts was significantly increased in the group of 4 mg/L fluoride at 48 h(0.108 ± 0.042,t =0.764,P＜ 0.05) compared with control group(0.081 ± 0.010); the value was also significantly increased in 1,2,4 mg/L groups at 72 h(0.089 ± 0.010,0.087 ± 0.012,0.098 ± 0.023; t =0.765,0.704,0.996; all P ＜ 0.05) compared with control group (0.070 ± 0.014) ; the expression of fibronectin mRNA was much higher in 1,2,4 mg/L groups at 48 h (0.61 ±0.06,0.77 ± 0.07,0.77 ± 0.07) and 72 h(1.61 ± 0.14,2.54 ± 0.20,2.75 ± 0.22) compared with control group [0.48 ± 0.04(t =0.111,0.182,0.182,all P ＜ 0.05),0.97 ± 0.08(t =0.093,0.109,0.108,all P＜ 0.05) ].A lot of mineralized nodules could be seen under light microscope in 1.00 and 10.00 mg/L groups.Conclusions The expression of fibronectin in bone of fluorosis rats and in vitro cultured osteoblasts are increased,and fluoride also promotes the mineralization nodules formation of osteoblasts.These results suggest that fibronectin may regulate the process of bone mineralization,and possibly play a role in the development of skeletal fluorosis.

Immunoglobulin binding protein gene and protein expression in femur tissue of fluorosis rats / 中国地方病学杂志

Objective To observe the protein and gene expression of immunoglobulin binding protein (BiP) in the femur of fluoride-treated rats, and preliminarily study the possible role of endoplasmic reticulum stress in the pathogenesis of skeletal fluorosis. Methods Sixty Wistar rats were divided into 4 groups according to body weight, n =15. The control and low-calcium groups were fed with normal diet(0.79％ calcium) and low-calcium diet(0.063％ calcium), respectively, and both drank tap water(fluoride concentrations ＜ 1 mg/L). High-fluoride and coexpesure to low-calcium groups were fed with conventional feed (0.79％ calcium) and low-calcium diet (0.063％ calcium), respectively, and both drank tap water containing sodium fluoride (sodium fluoride concentration of 221 mg/L). During experimental period, rats were measured body weight once a week with a stand diet and water available ad libitum. The experiment lasted for 12 weeks. The immunohistochemical and reverse transcription polymerase chain reaction(RT-PCR) techniques were used to detect the protein and gene expression of BiP in the femur of fluoride-treated rats and control subjects. Results The bone mineral contents of high fluoride, lowcalcium and coexposure groups[(0.131 ± 0019), (0.097 ± 0.011 ), (0.083 ± 0.007)g/cm] were lower than those of the control group[(0.159 ± 0.029)g/cm, all P ＜ 0.05]; the bone mineral density of low calcium and coexpesure to fluoride group[(0.243 ± 0.018), (0.223 ± 0.022)g/cm2] was lower than that of the control group[(0.296 ± 0.046)g/cm2, all P ＜ 0.05]. The immunohistochemical staining showed that the anti-BiP antibody positive osteoblasts were significantly increased in the low calcium diet and coexposure to fluoride groups than that in the control, and coexposure to fluoride elevated the positive cells than that in only low calcium diet group. The mRNA expression of osteopontin(OPN) and osteocalcin(OCN) in coexposure to fluoride with low-calcium group(1.36 ± 0.20, 1.31 ±0.11 ) was higher than that of the control groups (0.82 ± 0.16, 0.85 ± 0.15, all P ＜ 0.05) ; moreover, OPN expression significantly increased in this group than that of the only high fluoride group (0.97 ± 0.29, P ＜ 0.05). The mRNA expression of BiP in the low calcium and coposure to fluoride group (1.38 ± 0.24,1.35 ± 0.12) was significantly higher than that of the control group ( 1.14 ± 0.06, all P ＜ 0.05 ). Conclusions Higher fluoride or coexposure to low calcium diet stimulates the gene and protein expression in rat femur BiP, indicating that varying degrees of endoplasmic reticulum stress is likely involved in the pathogenesis of rat skeletal fluorosis.

Effects of low calcium and high fluoride on expressions of receptor activator of nuclear factor-kappa B ligang mRNA in spleens of rats / 中国地方病学杂志

Objective To study the different expressions of receptor activator of nuclear factor-kappa B ligang(RANKL) mRNA in spleens of rats fed with diet of low calcium and high fluoride. Methods A 2× 2×2 factorial design was used and the factors were calcium, fluoride and action time. In the design, 40 Wistar rats [average body mass(118.9±13.5)g] were divided into four groups randomly by weight: control with normal diet (0.790%, calcium), low calcium group with low calcium intake(0.063%, calcium), high fluoride group with normal diet and high fluoride intake(100 mg/L, fluoride) and low calcium and high fluoride group with low calcium and high fluoride intake. After 4 and 8 months, 5 rats of each group were sacrificed and total RNA was extracted from spleen. And the expression levels of RANKL mRNA were determined by reverse transcription polymerase chain reaction (RT-PCR). Results At time of 4 months, the expression level of RANKL mRNA was 0.13± 0.05,0.13± 0.03,0.17±0.02,0.27± 0.05 and at time of 8 months, it was 0.11 ± 0.01,0.16 ± 0.02,0.16± 0.03,0.36 ± 0.07 in control group, low calcium group, high fluoride group, low calcium with high fluoride group, repectively. The factorial design AVONA showed that low calcium and high fluoride had significant effects on RANKL mRNA expression(F = 40.224,56.679, all P < 0.05) while action time had not(F = 2.850, P > 0.05 ). The interactions of low calcium with high fluoride or high fluoride with action time were signifieant(F = 7.247, 18.789, all P < 0.05) while the interaction of high fluoride with action time was not(F = 1.751, P > 0.05). Conclusions Low calcium alone or high fluoride alone or low calcium with high fluoride or low calcium with action time can increase the the RANKL mRNA expression level. High fluoride does not affect the RANKL mRNA level as the action time is prolonged.

Study on oxidative stress and activity of alkaline phosphatase of rats exposed to different period of fluoride / 中国地方病学杂志

Objective To observe the status of oxidative stress and activity of alkaline phosphatase(ALP) in rats exposed to high fluoride for the different periods and to analyze the effect of fluoride on the activity of ALP and oxidative stress in fluorosis rats. Methods Twenty-four Wistar rats were divided into control and high-fluoride groups according to their body mass, 12 rats in each group. The control group drank tap water(sodium fluoride concentrations < 1 mg/L), and high-fluoride group drank tap water containing sodium fluoride(sodium fluoride concentrations 221 mg/L). On a standard diet and water available ad hbitum, each rat was measured body weight once a week in 1,4,8,12 week. The biochemical techniques were used to test the indicators of oxidative stress including malonaldehyde(MDA), superoxidedismutase(SOD), glutathione peroxidase(GPx), uric acid and activity of ALP in serum of fluorosis rats. Results There was a interaction between fluoride and time in the activity of ALP (F = 4.690,P < 0.05). The activity of ALP was obviously higher in rats exposed to fluoride for 1,12 week [ (19.29± 3.69), (15.72 ± 0.79)kU/L] compared to the control[ (14.08 ± 1.99),(12.91 ± 3.97)kU/L, all P< 0.05] ; the level of MDA was obviously higher in rats exposed to fluoride for 1,4 week [ ( 13.37 ± 4.38 ), ( 11.82 ± 2.08) μmol/L ] compared to the respective control[ (8.75 ± 3.24), (7.42 ± 2.62)μmol/L, all P < 0.05]; difference of SOD and GPx between control and high-fluoride groups was not statistically significant(all P > 0.05); the level of uric acid in serum was significantly higher in high-fluoride group for 1,4 week[ (89.53 ± 13.21 ), (88.47 ± 19.78 )μmol/L] compared to the control [ (77.79 ± 11.43 ), (65.42 ± i 3.42) μ mol/L, all P < 0.05 ], but the level of uric acid showed lower in high-fluoride group for 8,12 week [(67.21 ± 9.44), (73.95 ± 9.52)μmol/L] compared to the control [(77.79 ± 11.43), (65.42 ± 13.42)μmol/L]. Conclusions Effect of overdose fluoride on ALP is time-dependant. On the other hand,overdose fluoride stimulates the status of oxidative stress in a way unrelated to the exposure period.

Study on endoplasmic reticulum stress in bone tissue of fluorosis rats / 中国地方病学杂志

Objective To observe endoplagmic reticulum stress in bone tissue of fluomsis rats and further explore the pathogenesis of skeletal fluorosis.Methods 48 Wistar rats were divided into 4 groups according to their body mass.The control and low.calcium group were fed with normal diet(0.79%calcium)and low-calcium diet(0.79%calcium)respectively,and both drank tap water(sodium fluoride concentrations＜1 mg/L).High fluoride and low.calcium plus high-fluoride groups were fed with normal diet(0.79%calcium)and low-calcium diet (0.79%calcium)respectively,and both drank tap water containing sodium fluoride(sodium fluoride concentrations 221 mg/L).During experimental period,rats were measured body mass once a week with a stand diet and water available ad libiturn.The experimental period was 3 months.The biochemical techniques were used to test the indicators of oxidative stress and ALP in seFum of fluorosis rats.The total RNA was extracted from the one side of the femur,and the transcription level of Bip,Xbp1,CHOP and PDI were investigated by reverse transcription polymerase chain reaction(RT-PCR).Results The level of MDA in serum of low-calcium plus high-fluoride group wag higher than that of the control[(14.74±3.11)μmol/L vs(10.15±1.96)μmol/L,P＜0.05];the activity of GPx was ma~edly higher in hish-fluoride group compared with the control[(3.87±0.41)×103 U/L vs(2.85± 0.55)×103 U/L,P＜0.05];the level of uric acid in sel'um was significantly lower both in high-fluoride group and low-calcium plus high-fluoride group compared with the respective control and the low-calcium group[(73.95± 9.52)μmol/L vs(110.43±25.48)μmol/L,(54.32±22.09)μmol/L vs(101.71±17.01)μmol/L,P＜0.05]. The activity of ALP wag obviously higher in low-calcium plus high-fluoride group compared with the control [(24.77±4.57)×103U/L vs (12.91±3.97)×103U/L,P＜0.01)].The mRNA expression of Bip/GAPDH in bone tissue was markedly higher in bone of high-fluoride group and low-calcium plus high-fluoride group compared with the control(1.38±0.24,1.35±0.12 vs 1.14±0.06,P ＜ 0.05). The expression of Xbp1/GAPDH in bone tissue significantly increased in low-calcium plus high-fluoride groups compared with the control and the low-calcium group (1.48±0.20 vs 1.02±0.25,1.07±0.25,P ＜ 0.05 or ＜ 0.01);and CHOP/GAPDH in bone tissue significantly increased in low-calcium plus high-fluoride groups compared with the control(0.84±0.18 vs 0.52±0.07,P ＜ 0.05 ). Conclusions Accelerated osteogenetic action is seen in fluorosis rats,accompanied by oxidative stress and bone endoplasmic reticulum stress,which is likely involved in the pathogenesis of skeletal fluorosis.

Influence of fluoride on osteoprotegerin mRNA and protein expression in rat osteoblasts: an in vitro study / 中国地方病学杂志

Objective To study the influence of fluoride on the expression of osteoprotegerin(OPG) mRNA and protein in suckling rat osteoblasts. Methods Osteoblasts obtained from calvarial of suckling Wistar rats were cultured in vitro in the media supplemented with NaF at a series of doses[O(control), 1,2 and 4 mg/L groups], and OPG mRNA expression and protein were evaluated by RT-PCR and ELISA methods, respectively. Results OPG mRNA expression in suckling rat osteoblasts cultured in vitro significantly increased after exposure to NaF for 48 h and 72 h(F=333.48,808.34,P<0.05). OPG mRNA expression in suckling rat osteoblasts cultured in vitro after exposure to NaF for 48 h at different doses(0.810±0.003, 0.819±0.031 and 0.870±0.044 for 1,2 and 4 mg/L groups, respectively) compared with that of control (0.800±0.040, all P<0.05). OPG mRNA expression further increased for 72 h exposure to NaF(0.933±0.047,1.031±0.051,1.240±0.062 for 1,2 and 4 mg/L, respectively), significantly higher than that of the control (0.805±0.020,all P<0.05) and corresponding groups at 48 h. NaF doses and time exposure exhibited a significant synergistic effect on OPG mRNA expression(F=2004.16, P<0.05). NaF also enhanced OPG protein expression in suckling rat osteoblasts cultured in vitro. Significant differences were observed only in 4 mg/L group(0.228±0.014,0.277±0.048) and control(0.205±0.012,0.229±0.010) at 48 h and 72 h (P<0.05). In addition, OPG protein expression at 72 h post-exposure was higher than that at 48 h,but there was no synergistic effect between concentration and time(F=1.21,P>0.05). Conclusions The results suggested that NaF could increase OPG mRNA and protein expression in suckling rat osteoblasts with a synergistic effect between the doses and exposure time.

Influence of fluoride on Runx2 mRNA and protein expression in rat osteoblasts / 中国地方病学杂志

Objective To study the influence of fluoride on the expression of Runx2 in suckling rat osteoblasts. Methods Osteoblasts obtained from calvarium of suckling Wistar rats were cultured in the media supplemented with NaF at different doses(0, 1,2 and 4 rag/L), and Runx2 Mrna expression and protein expression were evaluated by RT-PCR and ELISA, respectively. Results Runx2 Mrna expression in suckling rat osteoblasts cultured in vitro significantly increased after exposure to NaF for 48 h at different doses (0.613±0.055, 0.773±0.070 and 0.775±0.070 for 1,2 and 4 mg/L,respecfively) compared to the control (0.482±0.043 ,P< 0.05). Runx2 Mrna expression further increased after 72 h exposure to NaF(0.969±0.048,1.229±0.061,1.255± 0.063 for 1,2 and 4 mg/L, respectively) ,which is significantly higher than the control(0.724±0.036,P<0.05) and corresponding groups at 48 h. NaF doses and exposure time exhibited a significant synergistic effect on Runx2 Mrna expression (P<0.05). Similarly, NaF also enhanced Bunx2 protein expression in suckling rat osteoblasts cultured in vitro. Significant differences were observed between groups exposed to NaF (1,2 and 4 rag/L) and control at48 h post-exposure (0.141±0.007, 0.143±0.008, 0.143±0.011 vs 0.129±0.012, P<0.05) as well as 72 h post-expesure(0.156±0.014, 0.168±0.018, 0.162±0.0100 vs 0.137±0.016, P<0.05). In addition, Runx2 protein expression at 72 h post-exposure was significantly higher than that at 48 h. Conclusions The results suggested that NaF could increase Runx2 expression in suckling rat osteoblasts with a synergistic effect between the doses and exposure time.

Differential expression of osteopontin and bax, bcl-2 by fluoride / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the differential expression of bax, bcl-2 and osteopontin by fluoride in the renal tubular cells in vitro.</p><p><b>METHODS</b>The renal tubular cells were cultured and exposed to sodium fluoride (NaF) in 1, 5, 7.5, 12.5 mg F-/L level. The transcription level of bax, bcl-2 and osteopontin were investigated by reverse transcription - polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>The expression of bax mRNA in 7.5 and 12.5 mgF-/L groups (optical absorption ratio value was 2.37 +/- 0.18 and 2.64 +/- 0.19 respectively) was significantly increased (P < 0.01). On the contrary, the level of bcl-2 obviously decreased (5 mg F-/L group optical absorption ratio value, 0.80 +/- 0.22, P < 0.05; 7.5 mg F-/L group optical absorption ratio value 0.71 +/- 0.22, P < 0.01). The expression mRNA of osteopontin was significantly increased when cells were exposed to fluoride at 7.5 mg F-/L (optical absorption ratio value 2.01 +/- 0.40 P < 0.01), in that group the tubular cell apoptotic trend was obvious.</p><p><b>CONCLUSION</b>NaF might induce tubular cell apoptosis via activation of bax expression and bcl-2 suppression. Osteopontin might protect the tubule against apoptosis in a lower fluoride level, but the function should be decreased in higher fluoride level.</p>

The effect of overdose fluoride on the proliferation and apoptosis of rat's incisor ameloblast / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the effect of overdose fluoride on the proliferation of rat's incisor ameloblast.</p><p><b>METHODS</b>20 Wistar rats were divided randomly into 2 groups: Group I (Control); Group II 50 mg/L F(-) were given. After 8 weeks treatment, the AgNORs stain and TUNEL technique were applied to analyze the effect of fluoride on the proliferation and apoptosis of ameloblasts.</p><p><b>RESULTS</b>The imagination analysis results showed that proliferation of pre-secretion ameloblasts were inhibited in group II as compared with the control group (P < 0.001). There was significant increase of apoptosis with the trend of migration toward secretion stage.</p><p><b>CONCLUSION</b>The mechanism of fluorosis mottled enamel may be the effect of overdose fluoride with inhibits proliferation and induces apoptosis of ameloblasts resulting in dysfunction of secretion or absorption of enamel matrix proteins.</p>

Expression of proto-oncogenes c-fos and c-jun in osteoblasts activated by excessive fluoride / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study expression of proto-oncogenes c-fos and its accompanying gene c-jun in osteoblasts activated by action of excessive fluoride in vivo and in vitro.</p><p><b>METHODS</b>Experimental Wistar rats were exposed to sodium fluoride (NaF) added to their drinking water, and NaF was also added in cell culture supernatant for osteoblast-like cells in vitro. Expression of both mRNA and protein of c-fos and c-jun in bone-tissue of rats with chronic fluorosis and cultured osteoblast-like cells were determined by hybridization in situ, Western blot and immunohistochemistry at varied time periods after exposure.</p><p><b>RESULTS</b>Sodium fluoride could stimulate the proliferation of osteoblast in rats with chronic fluorosis and induce expression of both c-fos and c-jun in all envelops of the spine bone, as compared with its control group. Value of optical absorption in mRNA expression of c-fos and c-jun was 139.63 and 126.37, respectively, in rats with NaF plus high-calcium, significantly lower than that in control group with high-calcium only (107.74 and 117.48, respectively) (P < 0.001). Immunohistochemical analysis showed that protein level of c-fos and c-jun was significantly higher in rats with NaF plus high-calcium than that in control rats with high-calcium only, with values of optical absorption of 139.16, 131.15, 149.98 and 149.19 (P < 0.05), respectively, and protein level of c-fos and c-jun was significantly higher in rats with NaF plus low-calcium than that in control rats with low-calcium only, with values of optical absorption of 117.24, 111.46, 132.46 and 129.79 (P < 0.05), respectively. Western blotting showed that level of protein expression of c-fos and c-jun in periosteal osteoblasts was significantly higher in all rat groups with NaF than that in all control groups, with values of optical absorption of 123.32, 116.60, 115.97 and 108.30, respectively. mRNA expression of c-fos and c-jun in osteoblast-like cells treated with NaF for 12 h increased obviously, and remained at high level 48 h after exposure, with values of optical absorption of 114.80, 161.14, 118.20, and 150.41, respectively, as compared with that in control group (P < 0.001 and P < 0.05).</p><p><b>CONCLUSIONS</b>Exposure to excessive fluoride could stimulate activation and proliferation of both osteoblasts in rats and cultured osteoblast-like cells in vitro, and cause enhanced expression of mRNA and protein of both c-fos and c-jun. Over-expression of c-fos could play an important role in development and proliferation of skeletal lesions in rats with chronic fluorosis.</p>

Effects of fluoride on osteoclastic activity of rats in vitro / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of fluoride on activities of tartrate-resistant acid phosphate (TRAP) and matrix metalloproteinase-9 (MMP-9) in rat osteoclasts cultured in vitro.</p><p><b>METHODS</b>Osteoclast was isolated mechanically from long bones of neonatal rats and cultured in vitro. Histochemical stain was applied to detect the effects of fluoride on activities of TRAP and in-situ hybridization was used to study the expression of MMP-9 mRNA in rat osteoclasts in vitro.</p><p><b>RESULTS</b>Number of TRAP positive cells was 154.2, 160.0, 170.6, 179.0 and 180.0 per cm(2), respectively for the rats with varied doses of fluoride, in a dose-response pattern but without statistical significance. The expression of MMP-9 mRNA increased with elevating dose of fluoride, especially in the rats with 1.00, 2.00 and 4.00 mg/L of fluoride, to 94.50, 94.64 and 104.97, respectively, significantly different from those in control group.</p><p><b>CONCLUSIONS</b>Fluoride can enhance the MMP-9 mRNA expression in cultured osteoclasts of rats.</p>

Effects of fluoride on ionized calcium and calcium channel in osteoblast-like cell in vitro / 中国应用生理学杂志

<p><b>AIM</b>To study the effects of fluoride (F-) on ionized calcium ([Ca2+]i) and calcium channel in osteoblast-like cell (OBLs).</p><p><b>METHODS</b>Investigating [Ca2+]i was by fluorospectrophotometry and recording the calcium currents of OBLs was using whole patch-clamp technique.</p><p><b>RESULTS</b>The addition of fluoride to the medium made a rapid and significant increase in free [Ca2+]i, especially in 100 ng F- /ml group. There were significances between control group and 50, 100 ng F- /ml groups. And 25 ng/ml F- could stimulate OBLs calcium channel open. Compared with control group, fluoride could significantly increase the amplitudes of calcium currents (P < 0.01), furthermore the activation was in dose-dependent manner.</p><p><b>CONCLUSION</b>Fluoride can make calcium channel open and then increase the concentrations of [Ca2+]i.</p>

The effect of fluoride toxicity on free radical level in rats / 中国地方病学杂志

Objective　Recently,it was reported the analy sis of bone free radical by using electron spin resonance (ESR),so this article aimed to determine the changes of bone free radical in fluoresis rats.Methods　To analyze the free radical level of bone in fluoresis rats fed with different dose of calcium by ESR method.Results　The free radical of bone in the group of low ca lcium level and the group low calcium+fluorides was higher than that in the cont rol group (P<0.01),but that in normal animal feeds (calcium-rich)+fluoride group was lower than that in the control group.Conclusions　Low doses of fluoride did not resulted in the increase of free radical in calcium-rich condition at short time,but at low calcium condition,fluoride could increase the level of free radical,these suggested that simple overdose of fluoride did not change the level of free radical of bone.

Fluorosis and oxidative stress / 中国地方病学杂志

Relevant literatures on the relationship betw een fluorosis and oxidative stress were reviewed.Based on most of the original papers published in recent years,we can see the increased free radicals and oxidative stress may occur in certain stage of fluoride intoxication,but confirmation of the causality between oxidative stress and fluoride-induced damages still remains much work to do.