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1.
Summary We have characterized the noncollagenous proteins of bovine bone using two high-resolution gel electrophoretic techniques.
Proteins were extracted from bone tissue by extended dialysis against 0.5 M EDTA. In some cases, a preextraction was done
in guanidine HCl. Bovine plasma was also examined to identify the proteins in bone that might also be present in blood. We
have scored 160 major, reproducible spots on our standard preparation bone map. These comprise about 40 individual protein
groups. There are many more minor spots present which puts the total number present over 200. Of these groups, 15 are not
present on plasma maps. Bone proteins identified in this way include actin, bone Gla-protein, and osteonectin. The remainder
are unknown. Bone Gla-protein is present in bovine bone in four isoelectric forms, pI=3.95−4.50. Electroblotting analysis
of EDTA and guanidine HCl extracted material failed to reveal any higher molecular weight immunologically reactive species.
The plasma proteins found in bone include, but are not limited to albumin, apo A-I lipoprotein, IgG, IgM, transferrin, α-2-HS-glycoprotein,
and hemoglobin. Extraction with guanidine HCl plus EDTA significantly enriches the yield for the nonplasma proteins but does
not appear to extract any additional bone proteins. 相似文献
2.
Summary Recent evidence of the occurrence of brushite in newly formed bone mineral prompted a study of the solubility properties of
brushite:apatite mixtures under physiological conditions and the influence on them of pH, lactate, pyruvate, and, particularly,
noncollagenous bone proteins (NCBPs). Brushite alone was surprisingly stable in solution at pH 7.4, 37°C. In the presence
of increasing amounts of apatite, hydrolysis of brushite to an insoluble phase occurred. A decrease of 0.1 pH unit or the
addition of 1.5 mM pyruvate or 10 mM lactate increased the ion activity product (Ca 2+×HPO
4
2−
) 3 or more times. However, within the loose envelope of bone such conditions so different from those in the circulation might
be only local or temporary. NCBPs, on the other hand, stabilized brushite in solution alone as well as in the presence of
apatite for days. They probably act by adsorbing strongly to the crystal surface and preventing nucleation by apatite. This
brushite-apatite-bone protein system exhibits solubility characteristics that can resolve the old problems presented by the
participation of the skeleton in extracellular calcium homeostasis on the one hand, and by the apparent insolubility of the
apatite mineral of bone on the other.
Deceased. 相似文献
3.
Sheep cortical bone powder was extracted with EDTA under mildly alkaline conditions. The extract was fractionated by CM-cellulose chromatography and caesium chloride gradient ultracentrifugation. Three chemically distinct fractions were obtained, including a sialoprotein fraction similar to that found in bovine bone. The serum proteins, albumin and immunoglobulin-G, present in trace quantities, were the most antigenic components of bone extract. Antibodies were produced in rabbits against sheep bone glycoproteins and detected by passive haemagglutination; these antibodies were weaker than those produced against articular cartilage proteins. Adsorption experiments indicated that major antigenic glycoproteins of bone matrix were not present in homologous articular cartilage tissue. 相似文献
4.
本实验目的是观察卵巢切除(OVX)大鼠皮质骨矿盐变化特点,研究其变化机理。选用SD.两月龄大鼠,摘除双侧卵巢,实验期60天。观察了OVX大鼠股骨干近、中和远1/3段矿盐含量的变化及股骨干近1/3段骨质中氨基多糖(GAG)、白蛋白和骨钙素(BGP)含量的变化。研究结果显示:OVX60天大鼠股骨干仅近1/3段矿盐含量显著降低,中和远1/3段矿盐含量无明显改变。股骨干近1/3段骨质中GAG和BGP含量显著增加,白蛋白含显显著降低。结果表明OVX60天大鼠股骨干近1/3段矿盐丢失与局部骨质内GAG含量增加,白蛋白含量和BGP质量降低有关。 相似文献
5.
Summary HCl-soluble proteins in human dentin ranging in age from 3 to 45 years exhibit amino acid compositional changes consistent
with β-elimination and hydrolysis of phosphoserine as well as dehydration and aldol cleavage of serine. This is the first
evidence of nonenzymatic mechanisms for in vivo degradation of hydroxy and substituted hydroxy amino acids in dentin. Decomposition of phosphoseryl residues reduces the
calcium-binding capacity of phosphoproteins. Elimination and dehydration reactions can produce variability in molecular weight.
The rates of decomposition may be rapid enough to cause the heterogeneity or “maturational” degradation seen in dentin phosphoproteins
during mineralization. 相似文献
6.
目的 研究 长管骨引导性骨再生成骨细胞来源,进一步完善引导性骨再生理论。方法 将42只成年雄性新西兰兔在双侧桡骨中段制作标准骨缺损不愈合模型,用硅胶膜呈管状包囊一侧骨缺损,另一侧作为对照侧。1只兔术后1 ̄12周分别于每周进行X线检查;30只兔,随机分为6组,分别于术后3天、1、2、3、4、5周外死取材,分别进行常规HE染色,SP方法BMP、BG抗体的免疫组化染以。结果 隔膜在骨缺损局部生成隔离密闭 相似文献
7.
Summary Fractionation of the EDTA-soluble, noncollagenous proteins of the organic matrix of chicken bone by Sephadex G-100 molecular
sieving has revealed that the majority of the organic phosphorus is present in two fractions, from one of which a homogeneous
phosphoprotein has been isolated. The purified phosphoprotein has an apparent molecular weight of 12,000 and contains both O-phosphoserine and O-phosphothreonine. 31P-NMR spectroscopy demonstrates that all of the organic phosphorus exists in the form of phosphomonoesters which have an average
pK 2 of 6.8. The phosphoprotein is highly acidic due to its high content of dicarboxylic acids in addition to the presence of
organic phosphorus. The characteristic amino acid composition of the phosphoprotein establishes its noncollagenous nature
and highlights the differences among bone, dentin, and enamel phosphoproteins. The absence of γ-carboxyglutamic acid distinguishes it from osteocalcin, the noncollagenous γ-carboxyglutamic acid-containing peptide of bone matrix. 相似文献
8.
We have used a model of rapid bone induction and resorption in rats initiated by the removal of bone marrow to define age-associated deficits. Here we report the sequential expression of various genes implicated in the formation and removal of bone following marrow ablation. Significant increases in alkaline phosphatase and procollagen 1(I) mRNA were observed by day 5, and of osteocalcin and osteopontin by day 6. At their peak, these mRNA levels were elevated three- to eight-fold and correlated with histological evidence of bone formation. No change in collagen II mRNA was observed, indicating that there was no cartilage phase. Collagenase activity increased 10-fold at day 9 and coincided with the beginning of bone resorption. Actin mRNA, a reference gene marker, remained at constant levels. Comparison of the response between adult (6 mo.) and old (24 mo.) rats showed the same temporal pattern, but a lower expression of bonerelated genes in older rats. Histological examination also showed that the bone volume and osteoblast number at day 6 were significantly lower in old rats. Furthermore, the percentage of mineralized bone was greatly reduced in the aged rat. This model system is currently being used to evaluate the effectiveness of interventions to up-regulate the bone activity in senescent rats. 相似文献
9.
Summary Gla-protein or osteocalcin is one of the most abundant noncollagenous matrix proteins found in bone and dentin. The present
study describes, with high resolution, the intracellular and extracellular distribution of Gla-protein in alveolar bone and
incisor dentin. Sections of tissues embedded in Lowicryl K4M were incubated with rabbit antibodies to rat dentin Gla-protein.
The site of the specific antigen-antibody reaction was revealed by the protein A-gold complex. Labeling was detected over
bone and dentin while fewer gold particles were present over prebone and predentin. Gold particles were also seen over the
protein synthetic organelles (rough endoplasmic reticulum, Golgi apparatus) of osteoblasts and odontoblasts. These findings
confirm, with improved resolution, previous light immunohistochemical studies, and offer the possibility to examine the secretory
pathway of the protein. 相似文献
10.
Summary In order to find out whether the concentration of bone gla-protein (BGP) is elevated in blood derived directly from bone tissue
compared to peripherically sampled blood a peroperative model was used. Blood was collected simultaneously from an armvein
and from the osteotomized surface of the bone during total hip replacement in 18 patients Peripheral blood was also collected
before the anaesthetic procedure. The anaesthetic and/or the operative procedure slightly decreased the level of BGP in the
peripheral blood during this short time interval, but serum BGP was not different in the bone-marrow derived blood and in
the peripheral blood taken simultaneously. These data suggest that BGP released from bone into the circulation is rapidly
cleared from the marrow and that peripheral serum BGP is a valid index of the bone-derived levels of BGP. 相似文献
11.
Summary To further investigate the relationship between oophorectomy (OF) and mineral bone loss, 15 women who underwent total hysterectomy
and bilateral oophorectomy were studied for 12 months after surgery. Mineralometric and metabolic data were obtained before
and after 3, 6, and 12 months. The women lost bone mineral content (measured by single photon absorptiometry) at the same
rate they lost cortical and trabecular bone, suggesting that bone loss after OF is a generalized phenomenon. Our data also
show that in increase in bone resorption takes place only in the first period after OF; the persistency of a negative bone
balance up to 12 months, accompanied by a reduction of osteocalcin serum levels, may be dependent on a reduced bone formation,
probably due to osteoblastic insufficiency. 相似文献
12.
Summary In an in vivo model of osteoclastic bone resorption, we previously showed that osteocalcin-deficient bone particles (BPs), derived from
warfarin-treated rats, were resorbed 50% as well as normal BPs and that they recruited fewer osteoclastic cells with decreased
tartrate-resistant acid phosphatase (TRAP) activity. In order to determine the specificity of the resorption response, we
evaluated the fate of implanted mixtures of normal and osteocalcin-deficient BPs. Normal and warfarin-treated donor rats were
prelabeled in vivo with oxytetracycline to permit identification of BPs from either source. Normal, osteocalcin-deficient, and 50∶50 mixtures
of BPs (either labeled or unlabeled) were implanted into normal rats and recovered 12 days later for enzymatic (TRAP) and
nondecalcified histomorphometric analyses. The incorporated oxytetracycline had no signficant effect on resorption of bone
particles. The recovered osteocalcin-deficient BPs were surrounded by fewer osteoclastic cells, were resorbed less, and contained
less extractable TRAP activity than normal BPs. In mixed BP implants with normal and osteocalcin-deficient BPs, each type
of bone particle elicited the same tissue response as when implanted separately. Remarkably, the different particles evoked
dissimilar osteoclastic responses and were resorbed to different extents, even when adjacent within the same implant. These
data suggest that osteocalcin may act as a substrate signal for resorption and that osteocalcin in the normal BPs does not
influence the cellular response to adjacent osteocalcin-deficient BPs. 相似文献
13.
Summary Serum bone Gla-protein (s-BGP or osteocalcin) and other serum biochemical parameters were measured in 19 subjects (8 women
and 11 men, aged 20–82 years) without any bone disease. Each subject simultaneously underwent an iliac crest biopsy; tetracycline
double-labeling was performed in 11 subjects, allowing correlations between s-BGP and bone histomorphometric parameters. s-BGP
was significantly correlated with static bone parameters: trabecular bone volume (r=0.74; P<0.001), osteoid surfaces (r=0.69; P<0.001), osteoblastic surfaces (r=0.68; P<0.002); dynamic bone formation parameters: total labeled surfaces (r=0.72; P<0.01); and the bone formation rate (r=0.69; P<0.01). We conclude that s-BGP is a valuable marker for evaluating bone formation in healthy adult subjects. 相似文献
14.
The mitogenic activity in the unfractionated mixture of proteins released from adult bovine bone matrix during demineralization with ethylenediaminetetraacetate (EDTA) has been examined. Bovine bone extract (BBE) from 1 to 25 μg protein per ml stimulated proliferation of chick embryo calvaria bone cells, newborn mouse bone cells, and osteoblastlike cell lines MMB-1 and ROS 17/2.8. BBE also stimulated DNA synthesis in cells from chick embryo cartilage, skin and skeletal muscle tissues and fibroblastlike BALB/c 3T3 and NRK cells. BBE contained β transforming growth factor (TGF) activity (NRK cell colony formation in soft agar in the presence of epidermal growth factor EGF). The cell specificity results suggest that (1) BBE contains more than one growth factor, including a βTGF and a factor that is not specific for bone cells, and (2) all of the bone derived growth factor activities that have been described previously, including SGF, are apparently present in BBE. Maximal stimulation of chick embryo calvarial cell DNA synthesis by BBE was equal to or exceeded maximal stimulation by nonosseous growth factors that have been reported to stimulate DNA synthesis in bone organ cultures (EGF, fibroblast growth factor, platelet-derived growth factor, insulinlike growth factor I, and multiplication stimulating activity). Combinations of BBE with maximally stimulatory concentrations of each growth factor stimulated DNA synthesis to a greater magnitude than did each growth factor alone. These results suggest that combinations of bone derived and systemic factors can coordinately stimulate bone cell proliferation. 相似文献
15.
Summary Serum bone Gla protein, a sensitive and specific marker of bone turnover, was measured in 35 acromegalic patients (14 untreated, 8 clinically active, and 13 cured) and 21 controls. We also examined 10 acromegalic patients before and after transsphenoidal surgery. Untreated and clinically active acromegalic patients had significantly higher serum bone Gla protein concentrations than the control subjects. Other nonspecific biochemical markers of bone metabolism, such as urinary hydroxyproline and urinary calcium, were also present in significantly greater amounts in active acromegalic patients. After treatment, a significant decrease in levels was observed, with return to control levels. In acromegalic patients, positive correlations were found among serum bone Gla protein and serum growth hormone and serum insulin-like growth factor I levels, as well as among levels of insulin-like growth factor I and serum phosphorus, serum alkaline phosphatase, and urinary hydroxyproline. These results suggest that serum bone Gla protein is a sensitive marker of the action of growth hormone in bone metabolism in acromegaly, a role that is probably mediated by insulin-like growth factor I. 相似文献
16.
本文测定了10例多发性骨髓瘤患者的血钙、磷、AKP、BGP、24小时尿HOP及腰椎2~4正位BMD,并且经化疗完全缓解后再次复查。结果(1)多发性骨髓瘤患者血Ca、P、AKP与正常对照无显著差异,化疗前后也无显著差异。(2)血BGP低于正常对照,24小时尿HOP高于正常对照,化疗后BGP增高,HOP下降。(3)BMD改变:10例患者中有3例骨量减低,6例骨质疏松,化疗后BMD有所增加。因此,血BGP、尿HOP和BMD对观察多发性骨髓瘤治疗效果有一定的临床指导意义。还初步探讨了破骨细胞因子对骨质破坏的机理。 相似文献
17.
Physical activity has been suggested to be one of the determinants of bone turnover and to prevent age-related bone loss. To examine this we measured the serum levels of osteocalcin (bone Gla-protein, BGP), C-terminal procollagen peptide (PICP), serum alkaline phosphatase, bone-specific alkaline phosphatase, and S-calcium as indices of bone formation in 19 actively performing and 15 ex-lifters. All were nationally or internationally ranked male athletes. Their values were compared with those from 38 age- and gendermatched controls. Actively performing weight lifters had 35% higher ( P<0.05) serum concentration of osteocalcin than the controls. The ex-lifters did not differ from the agematched controls. Also serum calcium was elevated in active lifters (6%) ( P<0.01) but not in ex-lifters. No difference was found for serum-ALP, B-ALP, or PICP in either of the groups. Our study indicates that in addition to an already documented and well-known higher bone mineral density in heavily exercising athletes, they have an indication of higher bone formation as measured by biochemical markers. In athletes who have retired from competitional training, however, the bone formation does not differ from that of more sedentary controls. 相似文献
18.
本文应用放射免疫分析方法对60例正常人及74例糖尿病患者的血清BGP进行了测定,并就其与BMD、血Ca、P及AKP等进行比较分析。结果表明:糖尿病患者血清BGP明显降低,而血Ca、P及AKP仍在正常范围.血清BGP与BMD呈负相关。说明血清BGP测定与BMD一样可以作为骨质疏松、糖尿病等代谢性骨病诊断与研究的一种敏感指标。 相似文献
19.
The aims of the study were to evaluate the use of bone-specific biochemical markers of turnover in type I osteoporosis, to test for evidence of heterogeneity of bone turnover in this condition, and to attempt to devise an uncoupling index by using the relationship between bone-specific biochemical markers of bone formation and bone resorption. In women with type I osteoporosis (mean age 64 years, SD 5; n=63) the mean level of serum osteocalcin, a specific biochemical marker of bone formation, was 9.9 ng/ml (SD 2.0), which was higher than the level in normal postmenopausal women (mean age 65 years, SD 6; n=8.9 ng/ml (SD 2.0; p<0.01). The variance of serum osteocalcin levels in the two groups was similar. Compared with this 11% increase in the biochemical marker for bone formation, the markers of bone resorption, total urinary deoxypyridinoline (bone-specific), pyridinoline and hydroxyproline were increased by 40% ( p<0.0001), 61% ( p<0.0001) and 25% ( p<0.01), respectively. Furthermore, these biochemical markers of bone resorption had greater variance in women in type I osteoporosis than in the normal postmenopausal women ( p<0.001). The urinary excretion of the free crosslinks deoxypyridinoline, pyridinoline and glycosylated pyridinoline were increased by 26% ( p<0.001), 17% ( p<0.01) and 13% (NS) respectively. An uncoupling index was calculated for the difference between urinary deoxypyridinoline and serum osteocalcin using the results from the normal women and expressed as z-scores. We conclude that the pyridinium crosslinks of collagen enable better discrimination between normal and osteoporotic women than does hydroxyproline. In osteoporosis there appears to be heterogeneity of bone resorption. Finally, an uncoupling index indicated that in osteoporosis bone resorption was increased to a greater extent than bone formation as compared with normal postmenopausal women. 相似文献
20.
Magnesium is known to have an essential role in determining the properties of bone, but the way in which Mg exerts its actions remains unclear. Although long-term Mg deficiency is known to produce osteopenia, the effects of short-term Mg deficiency have not been established. To test the hypothesis that Mg deficiency results in an altered pattern of initial mineralization and concomitant altered bone properties, the radiographic, histologic, chemical, and mechanical properties of the bones of rats given a Mg-deficient diet were compared to those of rats pair-fed the same diet supplemented with Mg. Short-term Mg-deficiency in the diet of growing rats produced a significant decrease in both the trabecular bone volume and the mineral content of the newly formed metaphysis, a significant increase in the Ca:P ratio, and a slight, but significant increase in hydroxyapatite crystallite size and/or perfection in the metaphysis. Comparable, but not significant, trends were found in the diaphyses. Metaphyseal bone osteocalcin levels were reduced in the Mg-deficient rats and lipid was more easily extracted from their bones. No detectable alterations in radiographic microstructure were noted. Mechanically, a significant decrease in the maximum three-point bend strength of the femurs of Mg-deficient rats was observed. These data support the hypothesis that short-term Mg deficiency affects the pattern of bone mineral formation. 相似文献
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