The effect of orthodontic force on the collagenase and phosphatase activities of the adjacent alveolar bone was evaluated. Maxillary canines of male cats were treated orthodontically with closed coil spring so as to exert about 80g force. Sixteen cats were equally divided into one control group and seven experimental groups (12 hrs, 24 hrs, 36 hrs, 2 days, 3 days, 5 days and 7 days after orthodontic treatment). After sacrificing all animals on experimental intervals, collagenase, acid phosphatase (ACP) and alkaline phosphatase (ALP) activities were determined in the pressure and tension sides of alveolar bones. ACP activities increased in both the pressure and tension sides, but significantly increased in the pressure side continuously. ALP activities increased in the tension side at early stage (1-2 days after treatment), but changed small amount in the pressure side. Collagenase activities increased in the pressure side, especially at late stage (5-7 days after treatment). These results suggest that (1) orthodontic force increases the ACP, ALP and collagenase activities generally and (2) activities of ACP and collagenase increase in the pressure side, but that of ALP in the tension side and (3) activities of ACP and ALP increase at early stage, but that of collagenase at late stage after orthodontic treatment. Therefore it is shown that there are time differences in the formation and destruction of organic and inorganic components in the bone metabolism of alveolus with application of the orthodontic forces.
Acid Phosphatase ; Alkaline Phosphatase ; Animals ; Cats ; Collagenases ; Humans ; Male ; Metabolism

The purpose of this study was to evaluate the effects of magnetic field on cellular activity of MC3T3-El cells. The celular activity was monitored by alkaline phosphatase and DNA synthetic activity in control, static magnetic field and pulsed electromagnetic field groups. A static magnetic field was applied to the cell by placing one, two, three, four, and five samarium-cobalt magnets above and below each cell plate for 24hours per day. A pulsed electromagnetic field with a frequency of 100 herz was applied for 10 hours per day. After 10 days of magnetic field exposure, there were increase of alkaline phosphatase activity in static magnetic field groups consisted of one, two and three magnetic groups, Alkaline phosphatase activities were not significantly increased in four and five magnetic groups, Application of pulsed electromagnetic field did not result in significant increase in alkaline phosphatase activity compared to control. DNA synthetic activity in both static and pulsed electromagnetic field group were not significantly different from that in control group, The result of this study suggest that magnetic field could have effect on the metabolism of bone cells related to the cellular metabolic process,
Alkaline Phosphatase* ; DNA* ; Electromagnetic Fields* ; Magnetic Fields* ; Magnets* ; Metabolism

OBJECTIVETo investigate the effects of 17beta-estradiol on the expression of alkaline phosphatase (ALP) and osteoprotegerin in human periodontal ligament cells.

METHODSHuman periodontal ligament cells (hPDLC) were obtained from periodontal tissue explants of teeth extracted for orthodontic treatment ALP activity was determined by PNPP, and OPG protein and corresponding mRNA levels were quantitatively detected by ELISA and RT-PCR RESULTS: ALP activity was significantly increased at 14 days and 21 days (P <0.05). 17beta-E2 of physiological concentration promoted secretion of OPG protein and expression of OPG mRNA (P <0.05). 17beta-E2 with high-dose showed no effect on OPG protein secretion and decrease OPG mRNA expression.

CONCLUSIONS17beta-E2 may have a positive impact on periodontium through promoting expression of ALP and OPG in hPDLC.

Alkaline Phosphatase ; metabolism ; Cells, Cultured ; Estradiol ; pharmacology ; Humans ; Osteoprotegerin ; metabolism ; Periodontal Ligament ; cytology ; drug effects ; metabolism

OBJECTIVESTo construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vitro.

METHODSCancellous bone were extracted from rabbit femoral head and cut into 1-mm-thick and 8-mm-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000 με respectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase (AKP) and tartrate-resistant acid phosphatase (TRAP) were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection.

RESULTSAfter being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000 με were significantly lower than those in the unstressed bone tissues (all P<0.05). DNA ladders were seen in the bone tissue under 3000 and 4000 με mechanical load. Moreover, there was significant enhancement in the activities of caspase-3/8/9 in the mechanical stress group of 3000 and 4000 με(all P<0.05).

CONCLUSIONSThe cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteoblasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000 με.

Acid Phosphatase ; metabolism ; Alkaline Phosphatase ; metabolism ; Animals ; Apoptosis ; Bone Development ; Caspases ; metabolism ; Finite Element Analysis ; Isoenzymes ; metabolism ; Male ; Rabbits ; Stress, Mechanical ; Tartrate-Resistant Acid Phosphatase ; X-Ray Microtomography

It is known that low-frequency pulsed electromagnetic fields (PEMFs) can promote the differentiation and maturation of rat calvarial osteoblasts (ROBs) cultured in vitro. However, the mechanism that how ROBs perceive the physical signals of PEMFs and initiate osteogenic differentiation remains unknown. In this study, we investigated the relationship between the promotion of osteogenic differentiation of ROBs by 0.6 mT 50 Hz PEMFs and the presence of polycystin2 (PC2) located on the primary cilia on the surface of ROBs. First, immunofluorescence staining was used to study whether PC2 is located in the primary cilia of ROBs, and then the changes of PC2 protein expression in ROBs upon treatment with PEMFs for different time were detected by Western blotting. Subsequently, we detected the expression of PC2 protein by Western blotting and the effect of PEMFs on the activity of alkaline phosphatase (ALP), as well as the expression of Runx-2, Bmp-2, Col-1 and Osx proteins and genes related to bone formation after pretreating ROBs with amiloride HCl (AMI), a PC2 blocker. Moreover, we detected the expression of genes related to bone formation after inhibiting the expression of PC2 in ROBs using RNA interference. The results showed that PC2 was localized on the primary cilia of ROBs, and PEMFs treatment increased the expression of PC2 protein. When PC2 was blocked by AMI, PEMFs could no longer increase PC2 protein expression and ALP activity, and the promotion effect of PEMFs on osteogenic related protein and gene expression was also offset. After inhibiting the expression of PC2 using RNA interference, PEMFs can no longer increase the expression of genes related to bone formation. The results showed that PC2, located on the surface of primary cilia of osteoblasts, plays an indispensable role in perceiving and transmitting the physical signals from PEMFs, and the promotion of osteogenic differentiation of ROBs by PEMFs depends on the existence of PC2. This study may help to elucidate the mechanism underlying the promotion of bone formation and osteoporosis treatment in low-frequency PEMFs.
Alkaline Phosphatase/metabolism* ; Animals ; Electromagnetic Fields ; Osteoblasts/metabolism* ; Osteogenesis/genetics* ; Rats ; TRPP Cation Channels/physiology*

Acid Phosphatase ; metabolism ; Alkaline Phosphatase ; metabolism ; Animals ; Carcinoma ; metabolism ; pathology ; HSP70 Heat-Shock Proteins ; metabolism ; Male ; Mice ; Proliferating Cell Nuclear Antigen ; metabolism ; Stomach Neoplasms ; metabolism ; pathology

The effects of centrifugal force on growth and differentiation of osteoblastic cells cultured in alpha-MEM containing 1% Fetal bovine serum were investigated by assays of DNA synthesis, alkaline phosphatase activity and osteocalcin- production in osteoblastic MC3T3-E1 cells. Centrifugation of the cells in low concentrations (1%) of fetal bovine serum caused a 1.9-fold increase of [3H] thymidine incorporation on day 3 from the start of centrifugation, and gradually decreased with culture up to day 9. Alkaline phosphatase activity was not affected by centrifugal force until day 5, and increased rapidly after day 7. Stimulation of DNA synthesis by centrifugation was abolished in the presence of H-7, an inhibitor of protein kinase C. These results suggest that centrifugal force stimulates the proliferation of osteoblastic cells through an autocrine secretion of some diffusable growth- promoting activity. Additional centrifugation of the cells also slightly stimulated alkaline phosphatase activity, although this did not directly influence the cell's osteocalcin-production activity.
Alkaline Phosphatase/metabolism ; Animal ; Cell Division ; Cells, Cultured ; Centrifugation ; DNA/biosynthesis ; Mice ; Osteoblasts/*physiology ; Stress, Mechanical

PURPOSE: The purpose of this study was to investigate the effects of low energy-ultraviolet B (UVB) irradiation on bone metabolism and turnover in mice. MATERIALS AND METHODS: Five-week old C57BL/6 mice were randomly allocated into two groups. Control group (n=35) was not exposed to UVB and experimental group (n=35) was exposed to low energy-UVB for 30 min a day during 7 days. Serological and radiological examination was performed at 0, 1, 2, 4, 8 week(s) of each group (n=7). RESULTS: Analysis of biochemical bone markers revealed that alkaline phosphatase (ALP) was detected higher in the UVB group compared to control group. Serum level of osteocalcin was higher in UVB group at 1st week after UVB irradiation (p=0.031). The mean value of Vitamin D was significantly higher in UVB group than control group (p=0.032). Bone mineral density (BMD) from both 5th lumbar spine (p=0.124) and femur (p=0.862) showed higher in UVB group than control group from two weeks after irradiation, but they were not statistically significant. CONCLUSION: Our study with radiological bone mineral density and serological tests for biochemical bone turnover markers revealed that ultraviolet irradiation contributed positive effect on bone formation.
Alkaline Phosphatase ; Animals ; Bone Density ; Femur ; Metabolism* ; Mice* ; Osteocalcin ; Osteogenesis ; Serologic Tests ; Spine ; Vitamin D

OBJECTIVE: To evaluate the effects of estrogen replacement therapy and pamidronate on the bone metabolism in the postmenopausal women. METHODS: This prospective randomized clinical trial examined the effects of oral pamidronate and conjugated equine estrogen, in combination and seperately, on biochemical markers of bone turnover in 140 women with low bone mass. Treatment included pamidronate (group I, n=50), or conjugated equine estrogen (group II, n=50), conjugated equine estrogen plus alendronate (group III, n=40) for 12 months. Biochemical markers of bone turnover were also measured at months 6 and 12 months. RESULTS: Serum osteocalcin and urinary deoxypyridinoline in Group I, Group II and Group III decreased signifiantly at 12 months of treatment (p<0.05). But total alkaline phosphatase decreased significantly during the treatment in Group III, but not in Group I and Group II. CONCLUSION: The combined treatment with pamidronate and conjugated equine estrogen is more effective in postmenopausal women with osteoporosis by decreasing bone biochemical markers.
Alendronate ; Alkaline Phosphatase ; Biomarkers ; Estrogen Replacement Therapy* ; Estrogens* ; Female ; Humans ; Metabolism* ; Osteocalcin ; Osteoporosis ; Postmenopause ; Prospective Studies

PURPOSE: The aim of this preliminary study was to determine the possible relationship between alkaline phosphatase (ALP) levels in the gingival crevicular fluid (GCF) and periodontal disease in men with hypergonadotropic hypogonadism (HH). MATERIALS AND METHODS: A total of 41 patients were divided into four groups. 9 with HH and periodontitis (P/HH), 11 with HH and gingivitis (G/HH), 12 with systemically healthy and periodontally healthy (H/C) and 9 with systemically healthy and periodontitis (P/C). The clinical evaluation of patients was based on the following parameters; the plaque index (PI), gingival index (GI), probing depths (PD) and attachment level (AL). The levels of ALP in the GCF were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: No significant difference could be detected in the mean clinical parameter data between the P/HH and P/C groups (p > 0.05). The periodontitis patients in both groups (P/C and P/HH) had higher mean probing depths than the H/C and G/HH patients (p < 0.001). The concentrations and total amounts of ALP in the GCF were significantly higher in both periodontitis groups compared to healthy and gingivitis groups (p < 0.01). The serum ALP levels were significantly higher in the P/HH group when compared to the other groups (p < 0.001). CONCLUSION: The findings of this study suggested that HH could be implicated as a contributing factor to the progress of periodontal disease.
Adolescent ; Adult ; Alkaline Phosphatase/*metabolism ; Gingival Crevicular Fluid/*enzymology ; Humans ; Hypogonadism/diagnosis/*enzymology ; Male ; Periodontium/*enzymology