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

OBJECTIVE: To evaluate the effects of combined estrogen and fluocalcic therapy on the bone metabolism in the surgicalyl menopausal women with osteopenia. METHODS: This prospective randomized clinical trial examined the effects of conjugated equine estrogen and fluocalcic in combination and separately, on BMD in 200 women with low bone mass. Treatment included 0.3 mg conjugated equine estrogen (CEE) (Group I), 0.625 mg CEE (Group II), 0.3 mg CEE plus fluocalcic (Group III), and 0.625 mg CEE plus fluocalcic (Group IV) for 12 months. Biochemical markers of bone turnover were also measured every six months. RESULTS: Urinary deoxypyridinoline in Group III and Group IV decreased signifiantly at 12 months of treatment (p<0.005). Serum osteocalcin and total alkaline phosphatase decreased slightly during the treatment in all groups but statistical significance was not foundsignificantly. CONCLUSION: The combined treatment with conjugated equine estrogen and fluocalcic is more effective in surgically menopausal women with osteopenia by decreasing bone biochemical marker.
Alkaline Phosphatase ; Biomarkers ; Bone Diseases, Metabolic* ; Estrogens* ; Female ; Humans ; Metabolism* ; Osteocalcin ; Prospective Studies

OBJECTIVETo study the effects of electromagnetic pulse (EMP) on bone metabolism of mice in vivo.

METHODSTwenty-four male BALB/c mice were divided into a control group and 2 experimental groups (n=8). The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase (ALP) activity, serum calcium concentration and osteocalcin level and trabecular bone volume (BV/TV, %) were measured immediately after EMP exposure by biochemical, ELISA and morphological methods.

RESULTSThe ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conclusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.

Alkaline Phosphatase ; Animals ; Bone and Bones ; metabolism ; Electromagnetic Fields ; Male ; Mice ; Mice, Inbred BALB C ; Osteocalcin ; blood

OBJECTIVETo isolate and culture bovine cementum-derived cells and investigate their biological properties.

METHODSCulture of primary bovine cementoblast (CB) were established from new-born bovine teeth. Cementum was manually dissected, fragmented, and digested twice with collagenase. Following a thorough wash to remove liberated cells, the remaining cementum fragments were plated and cultured in RPMI1640 containing 10% FCS and 1.5% Hepes. The cells in culture were identified using immunocytochemistry by expression of cementum attachment protein (CAP), osteocalcin (OCN) and alkaline phosphatase (ALP). ALP activity was measured by modified Gomori staining.

RESULTS(1) The cells in culture possessed the typical morphology of CB and there were no obvious change of the cell morphology up to 5th passage; (2) Cells in culture exhibited alkaline phosphatase activity and were also positive to CAP, OPN and ALP immunohistochemistry staining.

CONCLUSIONThe cells isolated and cultured in this experiment possess the properties of CB. This enables us to further observe its biological characteristics during cementogenesis and periodontal regeneration.

Alkaline Phosphatase ; metabolism ; Animals ; Cattle ; Cell Separation ; methods ; Cells, Cultured ; Dental Cementum ; cytology ; enzymology ; Immunohistochemistry

OBJECTIVETo study effective method of showing the microvascular architecture of human and rabbit skin flaps.

METHODSAccording to endogenous alkaline phosphatase activity, Gomori-Takamatsu method and NBT/BCIP method were used to observe the microvascular architecture.

RESULTSBoth methods had capability to demonstrate the microvascular architecture of the human skin flap, whereas the examining results of rabbits were negative.

CONCLUSIONSGreat difference of endogeneous alkaline phosphatase activity exists in different animals. Gomori-Takamatsu method and NBT/BCIP method are useful in study of microvascular architecture of human skin flaps.

Alkaline Phosphatase ; metabolism ; Animals ; Humans ; Male ; Microcirculation ; anatomy & histology ; Rabbits ; Surgical Flaps ; blood supply