Bone histomorphometric changes in the femoral neck of aging and ovariectomized rats

Background: This study characterizes the changes in cortical and cancellous bone and cross sectional moment of inertia of the femoral neck from aging and ovariectomized (ovx'd) rats to determine their role in the previously reported ovx-induced reduction of mechanical strength in the femoral neck. Methods: Undecalcified double-fluorescent lableled cross sections of femoral neck of 3.5-, 5.5-, 6.5-, and 8.5-month-old female rats and rats ovx'd at 3.5 months for 2, 3, and 5 months of 45 rats were studied. The estimated endocortical and trabecular surfaces, cortical and cancellous bone histomorphometry, and cortical moment of inertia were determined. Results: The femoral neck was adding cortical bone between 3.5 and 5.5 months of age by increasing cortical thickness and decreasing marrow cavity area. No change of cortical bone mass was found between 5.5 and 8.5 months and the same amount of cancellous bone was observed between 3.5 and 8.5 months of age. Ovariectomy-induced cancellous, but not cortical bone loss. The loss was due to a transient ovx-induced negative bone balance that by 5 months post-ovx produced a 42% loss in trabecular bone while the histomorphometry profiles were the same as controls. The crosssectional moment of inertia increased with age but did not differ significantly between ovx'd and controls. Conclusions: Our findings suggest that the ovx-induced cancellous bone loss could be a contributing factor to the reduced mechanical strength in the femoral neck of ovx'd rats reported previously. © 1995 Wiley-Liss, Inc.     

Comparison of the Effect of Vitamin K2 and Risedronate on Trabecular Bone in Glucocorticoid-Treated Rats: A Bone Histomorphometry Study

Purpose

To compare the effect of vitamin K₂ and risedronate on trabecular bone in glucocorticoid (GC)-treated rats.

Materials and Methods

Forty-eight Sprague-Dawley female rats, 3 months of age, were randomized by the stratified weight method into 5 groups according to the following treatment schedule: age-matched control, GC administration, and GC administration with concomitant administration of vitamin K₂, risedronate, or vitamin K₂ + risedronate. GC (methylprednisolone sodium succinate, 5.0 mg/kg) and risedronate (10 µg/kg) were administered subcutaneously three and five times a week, respectively. Vitamin K₂ (menatetrenone, 30 mg/kg) was administered orally three times a week. At the end of the 8-week experiment, bone histomorphometric analysis was performed on trabecular bone of the tibial proximal metaphysis.

Results

GC administration decreased trabecular bone mass compared with age-matched controls because of decreased bone formation (mineralizing surface, mineral apposition rate, and bone formation rate) and increased bone erosion. Vitamin K₂ attenuated GC-induced trabecular bone loss by preventing GC-induced decrease in bone formation (mineralizing surface) and subsequently reducing GC-induced increase in bone erosion. Risedronate prevented GC-induced trabecular bone loss by preventing GC-induced increase in bone erosion although it also suppressed bone formation (mineralizing surface, mineral apposition rate, and bone formation rate). Vitamin K₂ mildly attenuated suppression of bone formation (mineralizing surface) and bone erosion caused by risedronate without affecting trabecular bone mass when administered in combination.

Conclusion

The present study showed differential effect of vitamin K₂ and risedronate on trabecular bone in GC-treated rats.     

去卵巢大鼠骨组织的变化

目的:观察去卵巢对大鼠骨组织的改变,以建立妇女绝经后骨质疏松的动物模型。方法:选用3月龄SD雌性大鼠16只,随机分为对照组和去卵巢组。去卵巢组大鼠的双侧卵巢被切除,对照组做假手术,持续90天。用骨矿测定仪测量大鼠股骨的骨密度及在半自动图像分析仪观测胫骨近端骨小梁的静、动态指标,并在扫描电镜下观察大鼠股骨松质骨结构的改变。结果:与对照正常组比较,去卵巢组大鼠股骨的远端的骨密度降低(P<0.05)。胫骨骨小梁的面积减少,骨小梁间隙增大。股骨的骨小梁变少,变细,断裂,连接不紧密,表面常见骨吸收形成的陷窝。结论:用切除卵巢的方法造成雌激素缺乏,导致骨质疏松,作为研究因绝经引起的原发性骨质疏松的可靠动物模型。     

Effect of vitamin K2 on cortical and cancellous bones in orchidectomized young rats

OBJECTIVES: The purpose of the present study was to compare the effect of vitamin K(2) on cortical and cancellous bones in orchidectomized young rats. METHODS: Forty male Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into four groups with 10 rats in each group: baseline controls (BLC), age-matched controls (AMC), orchidectomy (ORX), and ORX+vitamin K(2) administration (K). Vitamin K(2) (menatetrenone) was administered subcutaneously twice a week at dose of 30 mg/kg each. The experimental period was 8 weeks, and cortical and cancellous bone histomorphometry was performed on the tibial shaft and the proximal tibia, respectively. RESULTS: Cortical area (Ct Ar) and cancellous bone volume (BV/TV) were significantly greater in the AMC group than in the BLC group. Ct Ar was significantly lower in the ORX group than in the AMC group, and cancellous BV/TV was also significantly lower in the ORX group than in the AMC group as a result of significantly increased eroded surface (ES/BS). Although Ct Ar in the ORX+K group did not differ significantly from that in the ORX group, cancellous BV/TV was significantly greater in the ORX+K group than in the ORX group, but still significantly lower than in the AMC group. This protective effect of vitamin K(2) on cancellous bone was attributable to normalizing increased ES/BS. CONCLUSIONS: Vitamin K(2) appears to act more strongly on cancellous bone than on cortical bone in ORX young rats. High dose vitamin K(2) could partially prevent the reduction of cancellous bone gain by normalizing raised bone resorption in ORX young rats.     

洛伐他汀对尾悬吊大鼠骨量及其骨髓基质干细胞增殖、分化的影响

背景：诸多临床和基础研究均发现他汀类药物具有成骨潜能,但未能完全证实他汀类药物促骨形成的作用。 目的：观察洛伐他汀体内给药对尾悬吊大鼠骨量和骨髓基质干细胞增殖﹑分化的影响,并探讨洛伐他汀防治失重型骨质疏松的作用潜能。 方法：18只雄性SD大鼠随机均分成对照组、尾悬吊组和悬吊给药组。对照组和尾悬吊组每天蒸馏水灌胃;悬吊给药组每天20 mg/kg洛伐他汀灌胃;两悬吊组大鼠后肢离地进行尾部悬吊,4周后处死所有大鼠。 结果与结论：与对照组比较,两悬吊组股骨各段骨密度、小梁相对体积、骨形态发生蛋白2 mRNA表达水平明显降低;骨小梁分离度、骨吸收周长百分数、破骨细胞数、类骨质周长百分数、碱性磷酸酶活性比及碱性磷酸酶mRNA表达水平显著增高;细胞增殖能力各组间差异无显著性意义。说明尾悬吊4周可导致大鼠骨量丢失;洛伐他汀体内给药不能阻止尾悬吊大鼠股骨骨量丢失,给药早期骨髓基质干细胞向成骨分化能力更强。     

Combined treatment with vitamin k2 and bisphosphonate in postmenopausal women with osteoporosis

Vitamin K2, as well as bisphosphonates, such as etidronate, alendronate, and risedronate, is widely used in the treatment with osteoporosis in Japan. Etidronate increases the lumbar bone mineral density (BMD), and prevents new vertebral fractures, in patients with osteoporosis, while alendronate and risedronate increase the lumbar and femoral neck BMDs, and prevent new vertebral and femoral neck fractures. Vitamin K2 enhances gamma-carboxylation of bone glutamic acid residues and the secretion of osteocalcin, sustains the lumbar BMD, and prevents osteoporotic fractures in patients with osteoporosis. Bisphosphonates, such as alendronate and risedronate, rather than vitamin K2, should be initially chosen for the treatment of osteoporosis, because they are more efficacious than vitamin K2. Available evidence suggest that risedronate prevents deterioration of the connectivity of the trabeculae in ovariectomized rats, whereas vitamin K2 increase the trabecular thickness, and that a combination of risedronate and vitamin K2 has a synergistic effect on preventing the deterioration of trabecular bone architecture induced by estrogen deficiency. Some studies have shown that combined treatment with etidronate and vitamin K2 appears to be more effective than etidronate alone in the prevention of new osteoporotic vertebral fractures. Based on these findings, combined treatment with vitamin K2 and bisphosphonates may be more efficacious in the prevention new vertebral fractures than a single treatment with bisphosphonate in postmenopausal women with osteoporosis. Thus, this combined treatment should be recommended for the treatment of postmenopausal osteoporosis. It is proposed that the role of vitamin K2 should be emphasized, when used in combination with bisphosphonates, especially in patients with vitamin K deficiency.     

Differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed normal or low calcium diet

The purpose of this study was to clarify the differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed a normal or low calcium diet. Ninety female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into nine groups with 10 rats in each group: baseline control, and 0.5% (normal) or 0.1% (low) calcium diet, either alone, or with vitamin K (30 mg/100g, food intake), vitamin D (25 micro g/100 g, food intake), or vitamin K + vitamin D. After 10 weeks of feeding, bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. Vitamin K supplementation increased the maturation-related cancellous bone gain and retarded the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation-related cortical bone gain in rats fed a normal calcium diet. Vitamin D supplementation reduced the maturation-related cancellous bone gain, prevented the reduction in periosteal bone gain, and enhanced the enlargement of the marrow cavity, with no significant effect on the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation- related cancellous and cortical bone gains with increased periosteal bone gain in rats fed a normal calcium diet. An additive effect of vitamin K and vitamin D on the maturation- related cortical bone gain was found in rats fed a normal calcium diet. This study shows the differential effects of vitamin K and vitamin D supplementation on cancellous and cortical bone mass in young rats fed a normal or low calcium diet, as well as the additive effect on cortical bone under calcium sufficient condition.     

去卵巢大鼠骨组织的变化

目的:观察去卵巢对大鼠骨组织的改变,以建立妇女绝经后骨质疏松的动物模型。方法:选用3月龄SD雌性大鼠16只,随机分为对照组和去卵巢组。去卵巢组的大鼠的双侧卵巢被切除,对照组做假手术,持续90天。用骨矿测定仪测量大鼠股骨的骨密度及在半自动图像分析仪观测胫骨近端骨小梁的静、动态指标,并在扫描电镜下观察大鼠股骨松质骨结构的改变。结果:与对照组比较,去卵巢组大鼠股骨远端的骨密度明显降低。胫骨骨小梁的面积减少,骨小梁间隙增加。股骨的骨小梁减少,变细,断裂,连接不紧密,表面常见骨吸收形成的陷窝。结论:用切除卵巢的方法造成雌激素缺乏,导致骨质疏松,是研究因绝经引起原发性骨质疏松的可靠动物模型。     

去睾丸大鼠骨形态计量学的研究

目的：探讨4月龄雄性大鼠去睾丸后骨量的变化，重点比较松质骨和皮质骨骨代谢的变化。方法：20只4月龄SD雄性大鼠，随机分为假手术组（A组）和去睾丸组（B组），同等条件下饲养90d后，取腰椎和胫骨中段行不脱钙制片进行骨形态计量学观察。结果：去睾丸组与假手术组比较，前者腰椎松质骨吸收增加、骨形成下降（P〈0．05），出现明显骨质疏松；皮质骨外膜的骨形成动态参数如矿化沉积率、骨形成率下降（P〈0．05），内膜骨形成和吸收均有增加趋势。结论：去睾丸90d能使大鼠松质骨出现骨质疏松，皮质骨丢失不如松质骨显著。松质骨对去睾丸敏感性比皮质骨高。     

Comparison of osteopenic changes in cancellous bone induced by ovariectomy and/or immobilization in adult rats

Background: Ovariectomy (OVX) and immobilization (IMM) in rats are useful models of osteopenia, replicating some aspects of osteoporosis in humans. The purpose of this study was to compare changes in cancellous bone after OVX and/or IMM. Methods: Differences in cancellous bone were determined at 6 and 12 weeks after OVX or IMM. Comparisons were also made when rats were ovariectomized or immobilized for 6 weeks and then immobilized (OVX/IMM) and ovariectomized (IMM/OVX), respectively, for 6 more weeks. The femurs were used to determine bone mineral content (BMC) using single photon absorptiometry (SPA) and for scanning electron microscopy (SEM). Tibias were collected for microradiography, image analysis, and histomorphometry of metaphyseal cancellous bone. Results: Six and 12 weeks after OVX, there was less cancellous bone mass, compared with controls, as indicated by SPA, SEM, microradiography, image analyses, and histomorphometry. Bone was lost primarily from the central metaphyseal regions in the OVX animals, whereas the loss occurred throughout the metaphyses in the IMM animals. There were more rodlike bone spicules and fewer platelike trabecule in the OVX and IMM groups compared with controls. Differences in the structural aspects of the cancellous bone, including differences in the types of bone struts and marrow star volumes, indicated less trabecular connectivity and greater trabecular separation in the OVX and IMM animals, compared with controls. Endochondral growth indices in the IMM groups tended to be less, whereas the OVX groups tended to be greater than controls. Cancellous bone formation rates were generally greater in the OVX groups but less in the IMM groups compared with controls. Osteoclastic resorption surfaces were substantially elevated in the IMM and OVX groups, particularly the IMM groups. Changes reflecting OVX and IMM, independently, were apparent in the OVX/IMM and IMM/OVX groups and indices of osteopenia were different from controls, including less bone mass, trabecular connectivity, and greater trabecular separation, bone turnover rates, and osteoclastic surface. Conclusions: These results demonstrate differences in the osteopenic changes that occur in cancellous bone following OVX or IMM. The changes were generally more dramatic in the IMM than in the OVX animals. When OVX and IMM were applied in combination, the osteopenic changes are particularly severe, emphasizing the importance of mechanical usage even with a deficiency of gonadal hormones. © 1994 Wiley-Liss, Inc.     

多尺度分析骨质疏松大鼠骨微结构变化

目的 多尺度分析骨质疏松大鼠的骨微结构变化。 方法 20只5月龄雌性SD大鼠随机选取12只实施双侧去卵巢(ovariectomy, OVX)手术,术后 8 周形成骨质疏松大鼠模型,另外 8 只作为假手术( SHAM) 对照组。 利用Micro-CT 和 SR-Nano-CT 定量分析骨质疏松大鼠在组织尺度下皮质骨和松质骨以及细胞尺度下骨细胞、骨陷窝小管和细胞外基质的微结构变化。 结果 组织尺度下,OVX 组皮质骨的截面积较 SHAM 组显著增大(P<0. 05),皮质骨骨密度和厚度较 SHAM 组虽有变化,但不显著;OVX 组骨小梁的骨密度、体积分数、厚度和骨小梁数量较 SHAM组显著降低(P<0. 01),骨小梁分离度显著增加(P<0. 01)。 细胞尺度下,OVX 组骨陷窝半轴长较 SHAM 组没有显 著差异,但 OVX 组骨陷窝厚度和骨小管直径较 SHAM 组显著增大(P<0. 05);同时,细胞尺度下 OVX 组皮质骨孔隙率较 SHAM 组显著增大(P<0. 05)。 结论 OVX 大鼠骨在组织和细胞尺度出现不同程度的微结构变化。 其中,组织尺度主要是松质骨丢失,皮质骨变化不大;细胞尺度骨陷窝小管网络孔隙显著增大,将直接影响皮质骨骨密度和强度。 多尺度分析骨质疏松大鼠骨微结构变化对于骨质疏松症的临床诊断及病理分析有潜在的应用价值。     

Vitamin D and its implications for musculoskeletal health in women: an update

Vitamin D is a hormone that controls phosphorus, calcium, and bone metabolism and neuromuscular function. Vitamin D synthesis is a process in which the skin, liver, and kidney are sequentially involved. The vitamin D pool is completed by the amount taken with food and supplements. Vitamin D deficiency causes osteopenia, precipitates and exacerbates osteoporosis, causes a painful disease, osteomalacia, and increases muscle weakness, which worsens the risk of falls and fractures. A high prevalence of vitamin D insufficiency exists in the apparently healthy population, osteoporotic patients, and patients with prior fractures. Factors contributing to low vitamin D levels include low sunlight exposure, decreased skin synthesis and intestinal absorption, and inadequate diet. The simplest way to correct hypovitaminosis is adequate nutrition and supplements. However, few patients with osteoporosis and/or fractures, receive adequate supplements. Vitamin D insufficiency may alter the regulatory mechanisms of parathyroid hormone and may induce a secondary hyperparathyroidism that increases the risk of osteoporosis and fractures, although the necessary degree of this is not established. Monitoring of serum 25-hydroxyvitamin D levels is the only way to assess vitamin D status. The ideal healthy blood levels of 25-hydroxyvitamin D are controversial, although a range from 30 to 60ng/mL is widely accepted. The role of vitamin D supplementation is to provide humans with the nutrient in an amount closer to the biological norm for our species. This amount of vitamin D results in optimal function of many aspects of health, including balance and muscle strength, thus reducing the risk of fracture beyond what is possible via the quality and quantity of bone itself.     

Adaptation of cancellous bone to aging and immobilization in the rat: a single photon absorptiometry and histomorphometry study

Nine-month-old female rats were double-labeled with bone markers and subjected to right hindlimb immobilization or served as control for 0, 2, 10, 18, or 26 weeks. The right limb was immobilized against the abdomen, thus unloading it, while the left limb was overloaded during ambulation. Single photon absorptiometry and cancellous bone histomorphometry were performed on dissected intact femur and 20-microns-thick undecalcified specimens of the proximal tibial metaphysis. In the unloaded limb, immobilization-induced muscle and cancellous bone loss occurred rapidly before 10 weeks and stabilized at 50% less bone mass after 18 weeks. Unloading caused a negative bone balance from a combination of elevated bone resorption and depressed bone formation. At 2, 10, and 18 weeks of immobilization, the ratios of bone resorption to bone formation surfaces were 1.6, 1.5, and 1.3, respectively; at 26 weeks, the ratio was 1. The bone loss was accompanied by poorer trabecular architecture (trabecular number decreased and trabecular separation increased), reaching the maximum at 18 weeks and stabilizing thereafter. These observations are in general agreement with Frost's postulate for mechanical effects on lamellar bone remodeling, and the findings on disuse osteoporosis in man. Therefore, the one-legged immobilization model can be useful in studies of the mechanisms of structural adaptation to mechanical usage.     

康力龙、泼尼松对大鼠骨组织形态学的影响

目的　探讨康力龙和泼尼松对大鼠骨组织形态学的影响。方法　 3月龄雄性SD大鼠 2 4只 ,体重 2 31 7± 33 3g随机分为三组。分别用蒸馏水、泼尼松 4 5mg·kg-1·d-1(每周二次 )和泼尼松 4 5mg·kg-1·d-1加康力龙 0 5mg·kg-1·d-1灌胃(每周 6次 ) ,持续 90天。用图像分析仪测算胫骨近端骨小梁的骨形态计量学指标 ,并在扫描电镜下观察大鼠腰椎的组织结构改变。结果　与对照组比较 ,泼尼松组大鼠胫骨的骨吸收增加 (破骨细胞数 + 92 % ) ,骨小梁间隙 (Tb .Sp)增宽 187% ,骨形成率(BFR/TV)减少 89% ,骨小梁面积 (%Tb .Ar)减少 (- 5 8% )。腰椎的骨小梁变少 ,变细 ,断裂 ,连接不紧密 ,表面常见骨吸收形成的陷窝。与泼尼松组比较 ,康力龙组骨形成增加 (BFR/TV + 75 2 % ) ,骨吸收减少 (破骨细胞数 - 41% ) ,骨量增加 (%Tb .Ar +87% ,Tb .Sp - 5 8% )。腰椎的骨小梁粗大 ,排列整齐 ,连接紧密。结论　长期使用泼尼松可导致骨质疏松 ,康力龙对此有防止作用。     

Age‐related Changes in Marmoset Trabecular and Cortical Bone and Response to Alendronate Therapy Resemble Human Bone Physiology and Architecture

In older humans, bone elongation ceases, periosteal expansion continues, and bone remodeling remains a dominant metabolic process. An appropriate animal model of type I and type II osteoporosis would be a species with sealed growth plates and persistence of bone remodeling. The rat is commonly used as a primary model, but due to delayed epiphyseal closure with continuous modeling and lack of Haversian remodeling, Food and Drug Administration guidelines recommend assessment of bone quality in an additional, nonrodent, remodeling species. This study investigated the skeletal characteristics of senescent marmosets to evaluate their suitability as an osteoporosis model. Animals were randomized across three experimental groups; controls for both sexes and marmosets receiving alendronate for either 30 or 60 days (28 μg/kg, sc, twice per week). Outcome measures included serum chemistry and bone biomarkers, DEXA, histomorphometry, micro‐computed tomography, and histopathology. Results showed that the adult marmoset skeleton has similar anatomical characteristics to the adult human, including the absence of growth plates, presence of Haversian system, and true remodeling of cancellous and cortical bone. Structural analyses of senescent marmoset cancellous bone demonstrated loss of trabecular mass and architecture similar to skeletal changes described for elderly men and women. Treatment with alendronate improved trabecular volume and number by reducing bone resorption, although bone formation was also reduced through coupling of bone remodeling. The common marmoset may provide a valuable model for research paradigms targeting human bone pathology and osteoporosis due to skeletal features that are similar to age‐related changes and response to bisphosphonate therapy reported for humans. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.     

大鼠实验性骨质疏松的扫描电镜观察

目的；探讨大鼠卵巢切除后和泼尼松所致骨质疏松时松质骨结构的改变。方法；切除雌性大鼠双侧卵旭及用泼尼松给雄性大鼠灌胃，分别制成绝经后骨质疏松和类固醇性骨质疏松动物模型。在扫描电镜下，观察大鼠股骨及腰椎松质骨结构的改变。结果：与正常组比较，骨质疏松的大鼠骨小梁变小，变细，断裂，连接中断，表面常见骨吸收形成的陷窝。结论：切除卵巢和泼尼松所致的骨质疏松均可造成松质骨三维结构的损害，使力学强度降低，增加骨折     

仙珍骨宝胶囊对去卵巢大鼠股骨颈骨代谢的影响

背景：用骨组织形态计量学方法探讨中药对去卵巢大鼠股骨颈骨质疏松的影响,可为采用中药防治绝经后妇女骨质疏松性股骨颈骨折提供实验依据。 目的：观察仙珍骨宝胶囊对去卵巢大鼠股骨颈松质骨的影响。 方法：3月龄SD雌鼠随机分为4组：基础对照组于实验开始时处死取材,去卵巢组和仙珍骨宝组去卵巢造模,仙珍骨宝组在去卵巢后灌胃仙珍骨宝,去卵巢组和年龄对照组灌胃生理盐水,90 d后处死,取股骨颈经不脱钙骨制片进行骨组织形态计量学参数测量。 结果与结论：与年龄对照组比较,去卵巢大鼠静态参数的骨小梁面积百分数和骨小梁数量明显减少(P < 0.01),骨小梁间隙明显增大(P < 0.01);动态参数的每毫米破骨细胞数和破骨细胞贴壁表面长度明显增加(P < 0.01),骨矿化沉积率明显减少(P < 0.01)。说明去卵巢能导致大鼠股骨颈骨量显著减少。给予仙珍骨宝治疗后,大鼠的骨小梁厚度及骨小梁面积明显增加(P < 0.05),每毫米破骨细胞数和破骨细胞贴壁表面长度有所减少,标记周长百分数则有所增加。说明仙珍骨宝能阻止去卵巢所致的大鼠股骨颈骨量丢失。     

Skeletal alterations in hypophysectomized rats: I. A histomorphometric study on tibial cancellous bone

Background: Hypophysectomy (HX) results in a cessation of bone growth and a decrease in bone metabolism. The purpose of this study is to examine the effect of HX on the static and dynamic histomorphometry of cancellous bone in the secondary spongiosa of the proximal tibial metaphysis in rats. Methods: Female rats, at 2 or 3 months of age, were HX and sacrificed at 0, 5 days, 2 and 5 weeks after the surgery. Age-matched intact rats served as controls. Cancellous bone histomorphometry was performed on doublefluorescent labeled, 30-um-thick sections of the proximal tibia. Tartrateresistant acid phosphatase histomorphometry was performed at 5 days on HX and control rats to evaluate the resorption in the metaphyseal bone. Results: Although the intact rats gained in body weight, tibial length, tibial weight, and density after 5 weeks, these changes did not occur following HX. As compared to the basal group, HX resulted in a decrease in the density and dry weight of the metaphysis. The histomorphometric data showed that the cancellous bone volume and trabecular number of the secondary spongiosa were decreased and the separation was increased in the HX rats. The dynamic results showed that HX significantly decreased longitudinal growth rate and tissue-based bone formation and resorption. However, the bone surface-based eroded surface, labeled surface, the mineral apposition rate, and the bone formation rate did not differ between the intact and the HX rats at either the 2 or 5 weeks study. Five days after HX, the bone surface and tissue-based osteoclast surfaces were significantly lower in the HX than in the intact rats. Conclusions: Pituitary hormone deficiency results in cancellous bone loss. The bone loss is due primarily to the suppression of longitudinal growth-dependent bone gain and the inhibition of tissue-based bone turnover with a lower bone formation relative to bone resorption. The surfacebased bone turnover is not affected. © 1995 Wiley-Liss, Inc.     

骨髓腔注射骨髓间充质干细胞防治模拟失重大鼠的骨质疏松

背景：模拟失重条件下自身骨髓间充质干细胞的增殖受到抑制,并且向成骨细胞分化的能力减弱,造成骨量减少与骨微结构的破坏,最终导致骨质疏松。 目的：观察同种异体骨髓间充质干细胞骨髓腔注射对模拟失重大鼠胫骨骨密度和骨组织微结构的影响。 方法：将雄性SD大鼠随机分为自由活动对照组、尾吊模拟失重组、细胞治疗组(尾吊模拟失重同时给予双侧胫骨骨髓腔注射成骨诱导的同种异体BMSCs细胞)。 结果与结论：与自由活动对照组相比,尾吊模拟失重组胫骨骨密度、骨小梁面积百分比、骨小梁数量和厚度均显著降低(P < 0.01),骨小梁分离度显著增加(P < 0.01)。与尾吊模拟失重组相比,细胞治疗组中胫骨骨密度、骨小梁面积百分比、骨小梁数量和厚度均显著增加(P < 0.01),骨小梁分离度显著降低(P < 0.01)。说明骨髓腔注射能够增加模拟失重大鼠骨密度,改善骨超微结构,减缓骨量丢失,有效防治骨质疏松。关键词：模拟失重;骨质疏松;骨髓间充质干细胞;骨密度;骨组织形态计量学 doi:10.3969/j.issn.1673-8225.2012.19.019     

低剂量唑来膦酸对去势拔牙大鼠破骨及成骨细胞的影响

文题释义：去势大鼠：即通过去势法建立骨质疏松动物模型,该模型建造方法主要有3种：去势法、维甲酸灌胃法和糖皮质激素肌注法,而去势法是目前最常用、最成熟的造模方法,主要是通过去除大鼠双侧卵巢至少3个月,构建骨量少、骨显微结构退化而引起骨脆性增加及骨折发生率升高的一种全身性骨病,即骨质疏松疾病模型。 TUNEL细胞凋亡检测：用于检测细胞在凋亡过程中细胞核DNA的断裂情况,其原理是生物素标记的dUTP在脱氧核糖核苷酸末端转移酶的作用下,可以连接到凋亡细胞中断裂DNA的3’-OH末端,并可与连接辣根过氧化酶的链霉亲和素特异结合,在显色剂DAB的存在下,产生很强的颜色反应(呈深棕色),特异准确定位正在凋亡的细胞。 背景：目前唑来膦酸虽能有效地预防绝经后妇女的骨丢失,但其对下颌骨的影响及其机制尚不清楚。 目的：观察去势大鼠经低剂量唑来膦酸作用后下颌骨组织病理学改变,探讨RANKL/RANK/OPG信号系统在唑来膦酸抑制骨吸收过程中的调控效应与机制。 方法：取36只雌性SD大鼠随机分为对照组、模型组和治疗组,后2组大鼠行两侧卵巢切除术,建立骨质疏松模型;对照组行假手术去除同等质量卵巢周围的脂肪。去卵巢3个月后,治疗组皮下一次性注射唑来膦酸20 μg/kg,对照组和模型组皮下注射相应剂量的盐水;用药1周后拔除大鼠左侧下颌磨牙,拔牙后4周麻醉动物取出拔牙侧下颌骨组织。通过影像学X 射线大致观察大鼠拔牙窝剩余牙槽骨状况,苏木精-伊红染色检测下颌骨皮质和骨松质的病理结构改变,TUNEL凋亡实验检测凋亡的成骨细胞数量,利用免疫组织化学技术检测下颌牙槽骨内细胞核因子κB受体活化因子配基(RANKL)、骨保护素、细胞核转录因子(NF-κB)的表达情况,最后Western blot检测核因子κB受体活化因子配基、细胞核转录因子蛋白的表达。 结果与结论：①拔牙4周后,治疗组相较模型组牙槽骨骨吸收减少,拔牙窝底有新骨形成;②苏木精-伊红染色可见,模型组的骨皮质变薄,骨小梁结构变细,甚至出现断裂,大量骨吸收陷窝,成骨细胞较少;治疗组骨皮质增厚,骨小梁结构正常,只有少量骨吸收陷窝,成骨细胞增多;③治疗组的成骨细胞凋亡数目显著低于模型组(P < 0.001);④免疫组织化学染色可见,治疗组RANKL蛋白、NF-KB p65蛋白表达显著低于模型组(P < 0.001,P < 0.002),骨保护素蛋白表达显著高于模型组(P < 0.001);⑤Western Blot结果显示,与对照组相比较,模型组的RANKL、NF-κB蛋白高表达,治疗组其表达量显著降低(均P < 0.001);⑥结果说明,唑来膦酸可通过下调细胞核转录因子信号通路抑制破骨细胞的分化,同时调控成骨细胞的凋亡。 ORCID: 0000-0002-0300-0460(程余婷) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程