Mechanisms for the enhancement of fracture healing in rats treated with intermittent low-dose human parathyroid hormone (1-34).

Recent reports have demonstrated that intermittent treatment with parathyroid hormone (1-34) [PTH(1-34)] increases callus formation and mechanical strength in experimental fracture healing. However, little is known about the optimal dose required for enhancement of fracture repair or the molecular mechanisms by which PTH regulates the healing process. In this study, we analyzed the underlying molecular mechanisms by which PTH affects fracture healing and tested the hypothesis that intermittent low-dose treatment with human PTH(1-34) can increase callus formation and mechanical strength. Unilateral femoral fractures were produced and a daily subcutaneous injection of 10 microg/kg of PTH(1-34) was administered during the entire healing period. Control animals were injected with vehicle solution alone. The results showed that on day 28 and day 42 after fracture, bone mineral content (BMC), bone mineral density (BMD), and ultimate load to failure of the calluses were significantly increased in the PTH-treated group compared with controls (day 28, 61, 46, and 32%; day 42, 119, 74, and 55%, respectively). The number of proliferating cell nuclear antigen (PCNA)-positive subperiosteal osteoprogenitor cells was significantly increased in the calluses of the PTH-treated group on day 2, and TRAP+ multinucleated cells were significantly increased in areas of callus cancellous bone on day 7. The levels of expression of type I collagen (COLlA1), osteonectin (ON), ALP, and osteocalcin (OC) mRNA were increased markedly in the PTH-treated group and accompanied by enhanced expression of insulin-like growth factor (IGF)-I mRNA during the early stages of healing (days 4-7). The increased expression of COL1A1, ON, ALP, and OC mRNA continued during the later stages of healing (days 14-21) despite a lack of up-regulation of IGF-I mRNA. These results suggest that treatment of fractures with intermittent low dose PTH(1-34) enhances callus formation by the early stimulation of proliferation and differentiation of osteoprogenitor cells, increases production of bone matrix proteins, and enhances osteoclastogenesis during the phase of callus remodeling. The resultant effect to increase callus mechanical strength supports the concept that clinical investigations on the ability of injectable low-dose PTH(1-34) to enhance fracture healing are indicated.     

Enhancement of graft bone healing by intermittent administration of human parathyroid hormone (1-34) in a rat spinal arthrodesis model

Bone grafting is commonly used to treat skeletal disorders associated with large bone defect or unstable joint. It can take several months, however, to achieve a solid union and bony fusion sometimes delays or fails especially in osteoporosis patients. Therefore, we used a rat spinal arthrodesis model to examine whether intermittent administration of human PTH(1-34) accelerates bone graft healing. Eighty-two male Sprague-Dawley rats underwent posterolateral spinal arthrodesis surgery using autologous bone grafts. Animals were given daily subcutaneous injections of hPTH(1-34) (40 microg/kg/day PTH group) or 0.9% saline vehicle (control group) from immediately after surgery till death. Five rats each were killed 2, 4, 7, and 14 days after the surgery, and mRNA expression analysis was performed on harvested grafted bone. Seven rats each were killed 14, 28, and 42 days after the surgery, and the lumbar spine, which contained the grafted spinal segment, was subjected to fusion assessment, microstructural analysis using three-dimensional micro-computed tomography, and histologic examination. Serum bone metabolism markers were analyzed. The results indicated that PTH administration decreased the time required for graft bone healing and provided a structurally superior fusion mass in the rat spinal arthrodesis model. PTH administration increased the fusion rate on day 14 (14% in the control group and 57% in the PTH group), accelerated grafted bone resorption, and produced a larger and denser fusion mass compared to control. mRNA expression of both osteoblast- and osteoclast-related genes was upregulated by PTH treatment, and serum bone formation and resorption marker levels were higher in the PTH group than in the control group. Histologically calculated mineral apposition rate, mineralized surface and osteoclast surface were also higher in the PTH group than in the control group. These findings suggest that intermittent administration of PTH(1-34) enhanced bone turn over dominantly on bone formation at the graft site, leading to the acceleration of the spinal fusion. Based on the results of this study, intermittent injection of hPTH(1-34) might be an efficient adjuvant intervention in spinal arthrodesis surgery and all other skeletal reconstruction surgeries requiring bone grafts.     

重组人甲状旁腺激素1-34对骨质疏松性骨折愈合影响的实验研究

目的研究重组人甲状旁腺激素1-34（rhPTH1-34）片段对大鼠骨质疏松性骨折愈合的影响。方法选择6个月龄雌性SD大鼠80只，随机分为rhPTH1-34组、雌激素组、对照组（骨质疏松组）及假手术组，每组20只。前三组切除双侧卵巢，假手术组暴露卵巢而不切除，术后3个月行右侧股骨中段骨折内固定术。术后分别皮下注射rhPTH1-34、苯甲酸雌二醇及等量生理盐水，进行骨密度、X线片组织病理学和生物力学检测，观察骨折愈合情况。结果rhPTH1-34组骨折局部骨密度明显高于对照组，差异有统计学意义（P〈0．05）；rhPTH1-34组比同时期的对照组骨痂生成量多，愈合时间提前。结论rhPTH1-34能促进骨形成，增加骨量，加快骨痂形成，促进骨质疏松性骨折愈合，同时能提高骨生物力学特性和抗骨折能力。     

甲状旁腺激素（1-34）与唑来膦酸联合治疗对骨质疏松大鼠骨折愈合的影响

目的探讨唑来膦酸(ZA)与甲状旁腺激素(PTH)的联合应用对去势大鼠骨折愈合的影响。方法对双侧卵巢摘除术12周后的大鼠行单侧胫骨水平骨切开术,并以髓内钉进行固定。所有大鼠在行骨折造模术后,随机接受赋形剂、ZA、PTH与ZA+PTH治疗。在治疗4或8周后,收集胫骨标本进行micro-CT、组织学及生物力学测试。结果与对照组相比,所有药物干预方法都促进了骨痂形成、增加了骨痂强度;ZA+PTH组在相对骨体积(BV/TV)、骨小梁粗度和生物力学上表现出了最强的促进作用。结论 ZA与PTH联合应用对去势大鼠的骨折愈合有累加作用。     

The effects of combined human parathyroid hormone (1-34) and zoledronic acid treatment on fracture healing in osteoporotic rats

Summary  

Ovariectomized (OVX) rats with tibial fracture received vehicle, ZA, PTH, or ZA plus PTH treatment for 4 and 8 weeks. Bone metabolism, callus formation, and the mass of undisturbed bone tissue were evaluated by serum analysis, histology, immunohistochemistry, radiography, micro-computerized tomography, and biomechanical test.     

Effects of recombinant human growth hormone (r-hGH) on experimental osteoporotic fracture healing

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国产重组人甲状旁腺素(1-34)对绝经后骨质疏松症的治疗作用研究

目的评价国产重组人甲状旁腺素(1-34)治疗绝经后骨质疏松症的临床疗效和安全性。方法入选绝经后骨质疏松症患者37例,年龄64.2±8.1岁,采用自身前后对照试验设计,每日皮下注射重组人甲状旁腺素(1-34)20μg,同时口服钙尔奇D600 0.6g/d,试验时间6个月,观察患者治疗前后骨密度变化、骨折发生情况,以及血尿常规、肝肾功、电解质、心电图改变等。结果试验期间有1例脱落;经过6个月治疗后,患者L1骨密度增加23.2%(P<0.05),L2骨密度增加18.0%(P<0.05),L3骨密度增加12.5%(P<0.05),L4骨密度增加19.9%(P<0.05),腰椎平均骨密度增加17.8%(P<0.05),股骨颈骨密度增加2.2%(P>0.05),大粗隆骨密度降低6.0%(P>0.05),Wards区骨密度降低1.3%(P>0.05);试验期间新发骨折2例,1例右肱骨骨折,另1例腰椎压缩骨折,无其他严重不良事件发生。结论重组人甲状旁腺素(1-34)治疗绝经后骨质疏松症有效,对腰椎骨密度改善显著,不良反应较轻。     

Enhancement of experimental fracture-healing by systemic administration of recombinant human parathyroid hormone (PTH 1-34)

BACKGROUND: Recombinant human parathyroid hormone (PTH [1-34]; teriparatide) is a new treatment for postmenopausal osteoporosis that can be systemically administered for the primary purpose of increasing bone formation. Because several studies have described the enhancement of fracture-healing and osteointegration in animals after use of PTH, we sought to critically analyze this skeletal effect. METHODS: Two hundred and seventy male Sprague-Dawley rats underwent standard, closed femoral fractures and were divided into three groups that were administered daily subcutaneous injections of 5 or 30 mug/kg of PTH (1-34) or vehicle (control). The dosing was administered for up to thirty-five days. Groups were further divided into three subgroups and were killed on day 21, 35, or 84 after the fracture. The bones were subjected to mechanical torsion testing, histomorphometric analysis, or microquantitative computed tomography. RESULTS: By day 21, calluses from the group treated with 30 mug of PTH showed significant increases over the controls with respect to torsional strength, stiffness, bone mineral content, bone mineral density, and cartilage volume. By day 35, both groups treated with PTH showed significant increases in bone mineral content and density and total osseous tissue volume, and they demonstrated significant decreases in void space and cartilage volume (p < 0.05). Torsional strength was significantly increased at this time-point in the group treated with 30 mug of PTH (p < 0.05). While dosing was discontinued on day 35, analyses performed after eighty-four days in the group treated with 30 mug of PTH showed sustained increases over the controls with respect to torsional strength and bone mineral density. No change was noted in osteoclast density at the time-points measured, suggesting that treatment with PTH enhanced bone formation but did not induce bone resorption. CONCLUSIONS: These data show that daily systemic administration of PTH (1-34) enhances fracture-healing by increasing bone mineral content and density and strength, and it produces a sustained anabolic effect throughout the remodeling phase of fracture-healing.     

Combined effects of recombinant human BMP-7 (rhBMP-7) and parathyroid hormone (1-34) in metaphyseal bone healing

Fracture healing involves multiple stages of repair and coordinated actions of multiple cell types. Consequently, it may be possible to enhance healing through treatment strategies that target more than one repair process or cell type. The goal of this study was to determine the combined effects of recombinant human bone morphogenetic protein 7 (rhBMP-7) and parathyroid hormone (PTH(1-34)) on metaphyseal bone healing. A wedge-shaped defect was created in the lateral aspect of the distal tibia in female New Zealand white rabbits (n=64) and was filled with tricalcium phosphate (TCP). Animals were assigned to four groups: 1) BMP-7 and PTH; 2) BMP-7; 3) PTH; and 4) control (TCP alone). In groups 1 and 2, 200 microg rhBMP-7 was incorporated into the TCP. Animals received daily subcutaneous injections of 10 microg/kg PTH(1-34) (groups 1 and 3) or saline (groups 2 and 4). Healing at 4 weeks was assessed using micro-computed tomography, histology, immunohistochemistry, and mechanical testing. Combined treatment with rhBMP-7 and PTH resulted in increased callus total volume (TV), mineralized volume (BV), average cross-sectional area, and bone mineral content (BMC) as compared to the control group (p<0.02). BV and BMC were also higher in the combined treatment group as compared to the BMP-7 group (p<0.02); however, tissue mineral density was highest in the BMP-7 group (p=0.002). New bone formation in the BMP-7 group was largely restricted to the defect site, while PTH promoted bone formation throughout the defect and surrounding regions. Combined treatment led to greater quantities of woven trabecular bone, increased trabecular thickness, decreased trabecular separation (p<0.04), and a trend towards increased numbers of osteoclasts (p=0.09). Combined treatment also resulted in increased torsional rigidity and compressive strength as compared to the control and BMP-7 groups (p<0.001). These results suggest that the improvements in mechanical function obtained with the combined treatment resulted from differing biological activities of rhBMP-7 and PTH. While the activities of rhBMP-7 appeared to be strictly anabolic, those of PTH appeared to work in the context of coupled remodeling. The combination of both agents led to greater bone volume as well as better microstructural organization and integration of this bone with the surrounding tissues.     

Human parathyroid hormone (1-34) accelerates natural fracture healing process in the femoral osteotomy model of cynomolgus monkeys

Several studies in rats have demonstrated that parathyroid hormone accelerates fracture healing by increasing callus formation or stimulating callus remodeling. However the effect of PTH on fracture healing has not been tested using large animals with Haversian remodeling system. Using cynomolgus monkey that has intracortical remodeling similar to humans, we examined whether intermittent treatment with human parathyroid hormone [hPTH(1–34)] accelerates the fracture healing process, especially callus remodeling, and restores geometrical shapes and mechanical properties of osteotomized bone.

Seventeen female cynomolgus monkeys aged 18–19 years were allocated into three groups: control (CNT, n = 6), low-dose PTH (0.75 μg/kg; PTH-L, n = 6), and high-dose PTH (7.5 μg/kg; PTH-H, n = 5) groups. In all animals, twice a week subcutaneous injection was given for 3 weeks. Then fracture was produced surgically by transversely cutting the midshaft of the right femur and fixing with stainless plate. After fracture, intermittent PTH treatment was continued until sacrifice at 26 weeks after surgery. The femora were assessed by soft X-ray, three-point bending mechanical test, histomorphometry, and degree of mineralization in bone (DMB) measurement. Soft X-ray showed that complete bone union occurred in all groups, regardless of treatment. Ultimate stress and elastic modulus in fractured femur were significantly higher in PTH-H than in CNT. Total area and percent bone area of the femur were significantly lower in both PTH-L and PTH-H than in CNT. Callus porosity decreased dose-dependently following PTH treatment. Mean DMB of callus was significantly higher in PTH-H than in CNT or PTH-L. These results suggested that PTH decreased callus size and accelerated callus maturation in the fractured femora.

PTH accelerates the natural fracture healing process by shrinking callus size and increasing degree of mineralization of the fracture callus, thereby restoring intrinsic material properties of osteotomized femur shaft in cynomolgus monkeys although there were no significant differences among the groups for structural parameters.     

rhPTH(1-34)对成骨细胞增殖、Collagen I及Osterix mRNA表达的影响

目的 观察间歇给予重组人甲状旁腺激素(1-34)[rhPTH(1-34)]对体外成骨细胞增殖、I型胶原蛋白(CoHagen I)及Osterix mRNA表达的影响,初步探讨rhPTH(1-34)对体外成骨细胞的作用机制.方法 体外培养新生大鼠成骨细胞,间歇循环给予0、10-11、10-10、10-9、10-8、10-7 M rhPTH(1-34)干预,(24 h为一循环,前12h给药),共2次,用MTT法检测细胞的增殖;RT-PCR法半定量测定成骨细胞Collagen I、Ostefix mRNA的表达.结果 显示rhPTH(1-34)可明显促进成骨细胞的增殖(P<0.05),促进成骨细胞Collagen I和Ostefix mRNA表达(P<0.05),101-9 M增殖、表达最明显,呈剂量依赖关系.结论 rhPTH(1-34)可促进成骨细胞的增殖、分化,可能是通过Collagen I和Ostefix mRNA表达来调节.     

rhPTH(1-34)对成骨细胞增殖、Collagen I及Osterix mRNA表达的影响

目的 观察间歇给予重组人甲状旁腺激素(1-34)[rhPTH(1-34)]对体外成骨细胞增殖、I型胶原蛋白(CoHagen I)及Osterix mRNA表达的影响,初步探讨rhPTH(1-34)对体外成骨细胞的作用机制.方法 体外培养新生大鼠成骨细胞,间歇循环给予0、10-11、10-10、10-9、10-8、10-7 M rhPTH(1-34)干预,(24 h为一循环,前12h给药),共2次,用MTT法检测细胞的增殖;RT-PCR法半定量测定成骨细胞Collagen I、Ostefix mRNA的表达.结果 显示rhPTH(1-34)可明显促进成骨细胞的增殖(P<0.05),促进成骨细胞Collagen I和Ostefix mRNA表达(P<0.05),101-9 M增殖、表达最明显,呈剂量依赖关系.结论 rhPTH(1-34)可促进成骨细胞的增殖、分化,可能是通过Collagen I和Ostefix mRNA表达来调节.     

基因重组人生长激素（r-hGH)对骨质疏松性骨折愈合影响的实验研究

目的　观察基因重组人生长激素 (r- h GH)对骨质疏松性骨折愈合的作用及影响 ,以期为骨质疏松性骨折提供一种有效的治疗方法。方法　选择 8月龄、雌性、SD大鼠 36只 ,随机分为治疗组与对照组 ,每组各 18只。手术方法建立骨质疏松性骨折实验模型后 ,治疗组动物每只每天皮下注射基因重组人生长激素 (r- h GH) 2 .7mg/ kg,连续 10天 ;对照组同法给予等量生理盐水。分别于用药后 2、4、8周检测血浆 IGF- 1浓度 ,并进行骨痂组织骨密度 (BMD)测定、骨痂组织力学强度测试等。结果　血浆 IGF- 浓度 :2周时 ,治疗组血浆 IGF- I浓度值较对照组明显增高 (P<0 .0 0 5) ,4～ 8周时 ,两组血浆 IGF- 浓度值水平相近 (P<0 .5或 P>0 .5) ;骨痂组织 BMD:4周时治疗组较对照组高 (P<0 .2 ) ,8周时却较对照组低 (P<0 .0 0 1) ;力学强度测试 :4～ 8周治疗组骨痂组织各扭转力学强度参数均较对照组高 ,其中最大扭转角在 4周时两组间差异显著 (P<0 .0 5)。结论　外源性基因重组人生长激素 (r- h GH)对实验性骨质疏松性骨折愈合有一定的促进作用。     

Effect of intermittent administration of human parathyroid hormone (1-34) on the mandibular condyle of ovariectomized rats

Intermittent administration of human parathyroid hormone (1-34) (PTH) increases bone mass in lumbar vertebrae and long bones of osteoporotic experimental animals. However, whether PTH has the same effect on jaw bones remains unclear. This study determined the effect of intermittent administration of PTH on rat mandibular condyle affected by estrogen deficiency. Fifty 6-month-old rats were either sham operated or ovariectomized, then divided into five groups depending on surgical procedure and hormone administration: sham + vehicle (SV), OVX + vehicle (OV), OVX + PTH 6 μg/kg once per week (OP6-1), OVX + PTH 60 μg/kg once per week (OP60-1), and OVX + PTH 20 μg/kg three times per week (OP20-3). PTH or vehicle was injected intermittently for 6 months in 5 rats of each group either immediately after surgery in a preventive administration experiment, or injected starting 6 months after surgery in a therapeutic administration experiment. The mandibles were excised, and bone morphometry was performed using confocal laser scanning microscopy and soft X-ray images. In both experiments, the bone volume of the OV groups was significantly lower than that of the SV group (P < 0.01); also, depending on dose and frequency, the bone volume of the OP group was higher than that of the OV group, particularly in the OP20-3 group. The value of mineralized surface of the OP groups was significantly higher than that of the OV group (P < 0.01), whereas the value of eroded surface of the OP groups was not significantly higher than that of the OV group. This study indicates that preventive and therapeutic intermittent administration of PTH in ovariectomized rats increase the bone formation in rat mandibular condyle without accelerating bone resorptive activity. This anabolic effect was best induced by the injection mode of 20 μg/kg three times per week. Received: Dec. 21, 1998 / Accepted: March 24, 1999     

Effects of teriparatide [recombinant human parathyroid hormone (1-34)] on cortical bone in postmenopausal women with osteoporosis.

Treatment with teriparatide (rDNA origin) injection [teriparatide, recombinant human parathyroid hormone (1-34) [rhPTH(1-34)]] reduces the risk of vertebral and nonvertebral fragility fractures and increases cancellous bone mineral density in postmenopausal women with osteoporosis, but its effects on cortical bone are less well established. This cross-sectional study assessed parameters of cortical bone quality by peripheral quantitative computed tomography (pQCT) in the nondominant distal radius of 101 postmenopausal women with osteoporosis who were randomly allocated to once-daily, self-administered subcutaneous injections of placebo (n = 35) or teriparatide 20 microg (n = 38) or 40 microg (n = 28). We obtained measurements of moments of inertia, bone circumferences, bone mineral content, and bone area after a median of 18 months of treatment. The results were adjusted for age, height, and weight. Compared with placebo, patients treated with teriparatide 40 microg had significantly higher total bone mineral content, total and cortical bone areas, periosteal and endocortical circumferences, and axial and polar cross-sectional moments of inertia. Total bone mineral content, total and cortical bone areas, periosteal circumference, and polar cross-sectional moment of inertia were also significantly higher in the patients treated with teriparatide 20 microg compared with placebo. There were no differences in total bone mineral density, cortical thickness, cortical bone mineral density, or cortical bone mineral content among groups. In summary, once-daily administration of teriparatide induced beneficial changes in the structural architecture of the distal radial diaphysis consistent with increased mechanical strength without adverse effects on total bone mineral density or cortical bone mineral content.     

重组人甲状旁腺素（1-34）治疗原发性骨质疏松症疗效观察

目的 观察重组人甲状旁腺素(1-34)[PTH(1-34)]治疗前后骨密度、骨代谢指标变化,以评价该药治疗原发性骨质疏松症疗效。方法 20例原发性骨质疏松症患者皮下注射PTH(1-34) 20μg 每天1次,每日口服钙尔奇D 600mg,连续治疗6个月。所有患者于治疗前、治疗后第3月、第6月检测腰椎(L2-L4)及股骨颈骨密度、血清骨特异性碱性磷酸酶（BSAP）、血清I型胶原交基C端肽(CTX)。结果 治疗后腰椎(L2-L4)骨密度较治疗前均显著升高,差异有统计学意义（P<0.05或P<0.01）。治疗后股骨颈骨密度较治疗前无明显改善(P>0. 05)。治疗后第3月、第6月BSAP较治疗前显著升高,差异有统计学意义（P<0.01）,治疗后第6月CTX较治疗前显著升高,差异有统计学意义（P<0.01）。结论 PTH(1-34)能显著提高腰椎（L2-L4）骨密度,对原发性骨质疏松症治疗有效。     

重组人甲状旁腺激素（1-34）和依降钙素治疗原发性骨质疏松症的随机对照研究

目的评价重组人甲状旁腺激素(1-34)[rhPTH(1-34)]治疗原发性骨质疏松症(OP)的疗效和安全性,并与依降钙素进行对比。方法 60例原发性OP患者按3:1被随机分入rhPTH(1-34)组(PTH组)和依降钙素组(CT组)。PTH组予rhPTH(1-34)20μg每日1次皮下注射,连续用药18月。CT组予益钙宁20U每周1次肌肉注射,连续用药12月。受试前检测腰2-4椎体(L2-4)和股骨颈骨密度(BMD)、血钙、血磷、尿钙、血清骨特异性碱性磷酸酶(BSAP)、尿Ⅰ型胶原交基C端肽(CTX-I),治疗后6、12、18月复查上述指标。结果与基线时比较,PTH组L2-4BMD在治疗6、12、18月时显著升高,股骨颈BMD在18月时显著升高,BSAP在6、12月时均显著升高,CTX-I校正值在6、12、18月时均显著升高;CT组L2-4BMD在治疗12月前升高,股骨颈BMD在12、18月时升高,BSAP12、18月时均显著下降,CTX-I校正值治疗前后无统计学差异。两组比较,PTH组患者在6、12月和18月时L2-4的BMD增长值和增长率均高于CT组。但CT组在治疗12月时股骨颈BMD增长值高于PTH组,不良反应:两组差异无统计学意义;PTH组有一过性高钙血症。结论 rhPTH(1-34)治疗原发性OP安全有效,对改善椎体BMD起效时间、增长速度和增长幅度均优于依降钙素,但改善股骨颈BMD较依降钙素起效更慢,增长幅度更小。     

rhPTH(1-34)对骨质疏松大鼠的作用及对sclerostin的影响

[目的]探讨人重组甲状旁腺素1-34(rhPTH1-34)对骨质疏松的治疗作用以及与血钙、磷代谢和生长因子的关系。[方法]用摘除大鼠双侧卵巢的方式制备骨质疏松模型,实验动物分为3个组:模型对照组(OVX组,摘除大鼠双侧卵巢不作任何处理);rhPTH1-34治疗组(PTH组,摘除大鼠双侧卵巢12周后用rhPTH1-34治疗8周);假手术组(sham组,仅切除卵巢周围的脂肪组织约3 g,术后12周纳入实验)。应用第4代双能X线骨密度仪测量大鼠股骨上段骨密度值(BMD);用ELISA法测定血清硬化蛋白(sclerostin)水平及骨钙素(BGP)浓度;用自动生化仪测定血清碱性磷酸酶(ALP)。[结果]rhPTH1-34治疗组、sham组均较OVX组股骨上段骨密度增高,组间比较差异有显著性(P<0.01)。rhPTH1-34治疗组血清BGP浓度值升高及sclerostin值降低,与OVX组比较差异有显著性(P<0.01)。各组血清钙、磷含量无明显变化,与OVX组比较差异无显著性,ALP值治疗组与OVX组无明显差异。[结论]rhPTH1-34能够预防股骨上段骨密度丢失,并且血清BGP浓度值升高及sclerostin值降...     

联合使用甲状旁腺激素和辛伐他汀对去卵巢大鼠骨质疏松症的治疗有叠加效应

目的探索联合使用甲状旁腺激素(PTH)和辛伐他汀(SIM)对去势大鼠骨质疏松的防治作用。方法 50只健康雌性SD大鼠随机行假手术(Sham,N=10)和切除双侧卵巢(OVX,N=40)手术后,OVX大鼠随机的分成4组:OVX组、SIM组、PTH组、PTH+SIM组。术后第1天开始给予药物治疗,SIM组:SIM灌胃(剂量5 mg/kg,每天1次),PTH组:PTH皮下注射(剂量60μg/kg,每周3次),PTH+SIM组:SIM灌胃和PTH皮下注射,剂量和用药频率和SIM组、PTH组相同,直至手术后12周为止,12时所有大鼠处死取胫骨行Micro-CT检测。结果结果表明SIM组、PTH组、PTH+SIM组和OVX组相比,胫骨近端都有较高的BMD、BV/TV、Tb.Th、Tb.N、Conn.D和较低的Tb.Sp,其中PTH+SIM组大鼠胫骨近端有最高的BMD、BV/TV、Tb.Th、Tb.N、Conn.D和最低Tb.Sp。SIM和PTH单独使用的效果明显低于他们联合使用对去卵巢大鼠骨质疏松的防治作用。结论联合使用甲状旁腺激素和辛伐他汀对去势大鼠骨质疏松的防治有叠加作用     

Effects of cyclic vs. daily treatment with human parathyroid hormone (1-34) on murine bone structure and cellular activity

Previously, we demonstrated that the human parathyroid hormone (1-34) fragment (hPTH(1-34)) increased bone strength in proportion to its effects on BMD and cortical bone structure in the murine femur by comparing cyclic vs. daily administration of hPTH(1-34). Both cyclic and daily regimens increased vertebral BMD similarly at 7 weeks. Here, we have examined the effects of daily and cyclic PTH regimens on bone structure and cellular activity by static and dynamic histomorphometry. Twenty-week-old, intact female C57BL/J6 mice were treated with the following regimens (n=7 for each group): daily injection with vehicle for 7 weeks [control]; daily injection with hPTH(1-34) (40 microg/kg/day) for 7 weeks [daily PTH]; and daily injection with hPTH(1-34) (40 microg/kg/day) and vehicle alternating weekly for 7 weeks [cyclic PTH]. At days 9 and 10, and 2 and 3 prior to euthanasia, calcein (10 mg/kg) was injected subcutaneously. At the end of study, the lumbar vertebrae 1-3 and the left femora were excised, cleaned, and processed for histomorphometry. In the lumbar vertebrae, daily and cyclic PTH regimens significantly increased cancellous bone volume (BV/TV), trabecular number, trabecular osteoclast and osteoblast perimeters, trabecular mineral apposition rate (MAR) and bone formation rate (BFR), and periosteal MAR and BFR compared to control, with no significant difference between the two PTH-treated groups. Increased trabecular tunneling was observed in both PTH-treated groups. Both regimens tended to increase vertebral cortical bone formation parameters with the effects at the periosteum site being more marked than those at the endosteum site, resulting in a significant increase in cortical width. In the femur, the effects of cyclic PTH on BV/TV, trabecular width and number, trabecular and endocortical osteoblast and osteoclast perimeters, cortical width, and trabecular and periosteal BFR were less marked than those of daily PTH. A cyclic PTH regimen was as effective as a daily regimen in improving cancellous and cortical bone microarchitecture and cellular activity in the murine vertebra.