Partial Prevention of Long-Term Femoral Bone Loss in Aged Ovariectomized Rats Supplemented with Choline-Stabilized Orthosilicic Acid

Silicon (Si) deficiency in animals results in bone defects. Choline-stabilized orthosilicic acid (ch-OSA) was found to have a high bioavailability compared to other Si supplements. The effect of ch-OSA supplementation was investigated on bone loss in aged ovariectomized (OVX) rats. Female Wistar rats (n = 58, age 9 months) were randomized in three groups. One group was sham-operated (sham, n = 21), and bilateral OVX was performed in the other two groups. OVX rats were supplemented orally with ch-OSA over 30 weeks (OVX1, n = 20; 1 mg Si/kg body weight daily) or used as controls (OVX0, n = 17). The serum Si concentration and the 24-hour urinary Si excretion of supplemented OVX rats was significantly higher compared to sham and OVX controls. Supplementation with ch-OSA significantly but partially reversed the decrease in Ca excretion, which was observed after OVX. The increase in bone turnover in OVX rats tended to be reduced by ch-OSA supplementation. ch-OSA supplementation increased significantly the femoral bone mineral content (BMC) in the distal region and total femoral BMC in OVX rats, whereas lumbar BMC was marginally increased. Femoral BMD was significantly increased at two sites in the distal region in OVX rats supplemented with ch-OSA compared to OVX controls. Total lumbar bone mineral density was marginally increased by ch-OSA supplementation. In conclusion, ch-OSA supplementation partially prevents femoral bone loss in the aged OVX rat model.     

中药骨康对去势大鼠骨矿含量和骨密度的影响

本实验旨在观察骨康口服液对通过切除卵巢诱发的绝经后骨质疏松症大鼠模型骨矿含量(BMC)和骨密度(BMD)的影响。通过双能X线扫描．结果显示：给药3个月时骨康组大鼠胫骨干骺端处的BMC和BMD显著高于造模组;骨康高、低剂量组与阳性对照组无显著差异。提示骨康和尼尔雌醇均可显著提高去势大鼠胫骨干骺端处的BMC和BMD．二者作用相当,且BMC和BMD的变化较一致。     

新型骨质疏松大鼠骨生物力学测试方法:股骨干骺端弯曲试验

 目的 建立一种新的骨生物力学测试方法用以评价去卵巢骨质疏松大鼠股骨干骺端生物力学的变化。方法 20只 5月龄雌性 SD大鼠随机分为去卵巢组和假手术组。术后 12周, 对全部大 鼠进行股骨骨密度和股骨远端骨组织计量学测定。所有大鼠取一侧股骨行中段三点弯曲试验, 另一侧 股骨行干骺端弯曲试验, 测定生物力学指标(最大载荷、屈服载荷、刚度)。对各生物力学指标和骨密度 及骨组织计量学指标行 Pearson相关分析。结果 去卵巢组股骨骨密度、骨组织计量学指标(骨小梁面 积百分比、骨小梁数量、骨小梁厚度)和生物力学参数(最大载荷、屈服载荷、刚度)较假手术组均明显降 低。在股骨干骺端弯曲试验中, 两组最大载荷和屈服载荷的差值明显大于三点弯曲试验所得的相应差值。 Pearson相关分析显示骨生物力学各参数与骨密度、骨组织计量学指标均呈正相关, 且股骨干骺端 弯曲试验的生物力学参数与骨密度、骨组织计量学指标的相关性明显强于股骨干三点弯曲试验。结论 建立了新型骨质疏松大鼠骨生物力学测试方法, 即股骨干骺端弯曲试验, 可用来评估去卵巢骨质疏松 大鼠股骨干骺端生物力学性能, 与股骨干三点弯曲试验相比, 其敏感度更高, 与骨密度和骨组织计量学 参数的相关性更强。     

前交叉韧带切断对卵巢切除大鼠股骨骨折愈合的影响

目的观察前交叉韧带切断(OA动物模型)对双侧卵巢切除大鼠(OVX绝经后骨质疏松模型)股骨骨折愈合的影响。方法12周龄SD大鼠共70只，分成基础对照组(Basal)、假手术组(Sham)、双侧卵巢切除术组(OVX)、卵巢切除 前交叉韧带切断术组(OVX OA)、假手术 骨折组(Sham F)、卵巢切除术 骨折组(OVX F)、卵巢切除 前交叉韧带切断 骨折组(OA OVX F)，每组10只大鼠。所有受试大鼠在处死前第10d天和第4d天分别皮下注射盐酸四环素和钙黄绿素行双荧光标记。基础对照组在实验开始时杀死，其余6组在术后6W杀死，取大鼠右侧股骨标本。然后，分别进行CR摄片、组织形态学染色，以及应用Norland-XR36双能X线骨密度仪(DXA)测量右股骨远段骨密度和中段骨密度，并将股骨远段及骨折段骨痂进行硬组织包埋、切片，作骨组织形态计量学测量。结果①OVX OA组与OVX组比较，股骨远段。BMD和BWTV显著增加；②OVX F组与Sham F组比较，骨痂(股骨中段)BMD和BV／TV显著降低：③OVX OA F组与OVX F组比较，骨痂(股骨中段)BMD利BV／TV无统计学差异。结论①骨质疏松不仅延缓骨折愈合过程，而且降低骨折愈合质量；②在此动物模型中，骨性关节炎延缓股骨骨质疏松的发生，但是，对骨质疏松性骨折的愈合没有确切的促进作用。     

The effects of nandrolone decanoate on bone mass and metabolism in ovariectomized rats with osteopenia

The effects of nandrolone decanoate (ND) treatment on bone mass and metabolism were studied in ovariectomized (OVX) rats with osteopenia. The 6-month-old rats were divided into Sham (n = 12) and OVX (n = 24). The OVX rats were allowed to lose bone for 6 weeks. At 6 weeks post ovariectomy, the OVX rats were divided into two groups: (1) OVX + Vehicle and (2) OVX + ND. The effects of ND on bone mineral density (BMD), bone mineral content (BMC), and bone metabolism were studied by dual-energy X-ray absorptiometry (DXA) and biochemical markers including urinary pyridinoline (Pyr), deoxypyridinoline (Dpyr), and serum osteocalcin. After 24 weeks of treatment, histomorphometry of the right tibiae and the wet weight of the gastrocnemius and soleus skeletal muscles were also examined. Ovariectomy resulted in a significant increase in biochemical markers and a significant decrease in spine BMD (0.221 ± 0.016 g/cm² in OVX group vs 0.239 ± 0.008 g/cm² in Sham group) and BMC (0.550 ± 0.055 g in OVX group vs 0.605 ± 0.042 g in Sham group) at 6 weeks post ovariectomy. Spine BMD (0.227 ± 0.017 g/cm²), femoral BMD (0.263 ± 0.012 g/cm²), and bone density of femur (1.035 ± 0.036 g/cm³) in the OVX + ND group were significantly greater than those in the OVX + Vehicle group (0.204 ± 0.013 g/cm² for spine BMD, 0.243 ± 0.009 g/cm² for femoral BMD, 0.938 ± 0.06 g/cm³ for bone density of femur) after 24 weeks of treatment. ND treatment decreased urinary Pyr and Dpyr significantly in OVX rats. Histomorphometric findings indicated that ND-treated rats had greater cancellous bone volume, greater trabecular number, greater trabecular thickness, and less trabecular separation than vehicle-treated OVX rats. OVX rats had greater wet weight of the gastrocnemius and soleus muscles than rats treated with ND. The data suggest that the effect of ND on bone mass is not influenced by the condition of the muscles in OVX rats. Our findings indicate that ND blocks further bone loss by inhibition of bone resorption in OVX rats with osteopenia. Received: August 25, 1999 / Accepted: January 28, 2000     

糖皮质激素对成年大鼠骨量的影响

目的利用双能X线吸收法(DXA)探讨成年大鼠接受糖皮质激素后骨量变化的规律。方法 21只44周龄SD雌性大鼠分别假性去卵巢+未注射糖皮质激素(SHAM组)、摘除双侧卵巢(OVX组)或注射甲基强的松龙[2.5 mg/(kg·d)](PRED组),应用扇形束DXA(QDR-4500A)每4周测定一次全身骨密度(BMD)、骨矿含量(BMC)、骨骼面积(AREA);术后12周处死,测定离体腰椎、股骨、胫骨及其兴趣区的BMD、BMC、AREA。压缩试验测定第二腰椎最大载荷和弹性模量。结果 (1)术后8周开始OVX组体重显著重于同龄SHAM组(8周时,P0.05,12周时P0.01),术后4周开始PRED组体重显著轻于同龄SHAM组(P0.05);(2)术后12周OVX组整体BMC显著高于SHAM组(P0.05),术后8、12周OVX组整体BMC显著高于PRED组(P0.05);(3)术后12周OVX组离体第5、6腰椎BMD及第6腰椎BMC显著低于SHAM组和PRED组(P0.05),PRED组离体各腰椎BMD、BMC、AREA与SHAM组无明显差异;(4)术后12周与SHAM组比较,OVX组离体股骨(-7.42%)、股骨远端(-10.85%)和近端(-6.92%)、胫骨近端(-11.40%)BMD显著降低(P0.05),其中股骨、股骨远端、胫骨近端BMC也显著降低(P0.05);(5)术后12周与SHAM组比较,PRED组离体股骨及各区BMD、BMC、AREA无显著性差异,整体胫骨及各区BMD无显著性差异;(6)术后12周与SHAM组比较,OVX组及PRED组胫骨中远端骨量增加;(7)与SHAM组比较,OVX组最大载荷和弹性模量显著降低,PRED组最大载荷显著降低。结论成熟期大鼠接受甲基强的松龙后,皮质骨和松质骨骨量没有显著变化,DXA检查难以发现其骨丢失情况;力学性能改变提示糖皮质激素更多的是引起骨质量的改变而导致了力学性能的下降及骨折的发生。     

间歇皮下注射人甲状旁腺激素不同片段(hFTH1-34及 hFTH1-84)对去卵巢大鼠股骨及腰椎骨量的影响

目的 比较间歇皮下注射人甲状旁腺激素不同片段（hPTH1-34)及（hPTH1-84)对完整雌性（Non-OVX)大鼠和去卵巢（OVX）大鼠股骨及腰椎1－4骨矿物含量（BMC）和骨密度（BMD）的影响。方法 Wistar雌性大鼠176只，分为hPTH1-34和hPTH1-84两大组（各80只及96只），每大组及各自分4组（每组各20只或24只），分别为：两组安慰剂组（未切卵巢及切卵巢）用安慰剂（PBS）进行皮下注射，每周3次，共2周；两组治疗组（未切卵巢及切卵巢）用hPTH1-34或hPTH1-84，皮下注射，每周3次，共2周。结果 1．卵巢切除术后3个月大鼠股骨及腰椎1－4BMC和BMD明显下降；2．两种片段的甲状旁腺激素（hPTH1-34及pPTH1-84)间歇注射均能使Non-OVX大鼠和OVX大鼠股骨及腰椎1－4BMC和BMD较相应对照组明显升高；且腰椎1－4较股骨的BMC和BMD升高更明显；3．OVX大鼠治疗后股骨与腰椎1－4BMC和BMD的升高率较Non-OVX大鼠更明显；OVX大鼠在治疗后股骨及腰椎骨量能恢复到去卵巢前水平；4．hPTH1-34较hPTH1-84更明显的使完整大鼠和OVX大鼠股骨BMC和BMD升高。结论 间歇皮下注射人甲状旁腺激素对大鼠股骨及腰椎骨量均有增高作用，尤其对腰椎的骨量以及对去卵巢大鼠骨量升高作用更明显；hPTH1-34片段对大鼠股骨骨量的增高作用强于hPTH1-84片段。     

骨质疏松动物实验骨折风险性分析

目的:评价骨质疏松动物模型发生骨折的风险性.方法:健康雌性SD大鼠36只,随机分为实验组和对照组各18只.实验组切除双侧卵巢,对照组仅切开皮肤.于术后2、4、8周两组处死6只大鼠,作松质骨(腰椎)和皮质骨(股骨干)骨密度(BMD)组织形态学和力学测定.结果:与对照组相比,手术组松质骨BMD 2、4、8周均明显下降,2周皮质骨无明显差异,4、8周则明显下降;股骨中段骨皮质厚度变薄;骨小梁体积(TBV)占全部骨组织体积(TTV)的百分比明显减少;成骨细胞和破骨细胞明显增多;股骨最大弯曲载荷、腰椎最大压缩载荷下降.     

Mechanical Properties of Femoral Diaphysis and Femoral Neck of Female Rats Chronically Exposed to Various Levels of Cadmium

The effect of chronic exposure to cadmium (Cd) on the mechanical properties of femoral diaphysis and femoral neck was investigated on a rat model of human exposure. Three-week-old female Wistar rats were exposed to Cd in drinking water at concentrations of 1, 5, 50, or 100 mg/L for 12 months. Biomechanical properties of the femoral diaphysis were evaluated in a three-point bending test and those of the femoral neck in a bending test with vertical loading of the head. Bone mineral content (BMC) and bone mineral density (BMD) at the whole femur, and BMD at the diaphysis and proximal femur (head and neck region) of the Cd-treated rats decreased in a dose-dependent manner, except for the diaphyseal BMD at a Cd concentration of 1 mg/L. Exposure to Cd concentrations of 1 and 5 mg/L had only little effect on the diaphyseal mechanical properties (decreased yield load with unchanged bending strength, stiffness, yield stress, ultimate stress, and Young modulus), whereas the bending strength and stiffness of the neck decreased and the yield load clearly tended to decline or declined. The effect of Cd at the two locations was more marked in the 50 and 100 mg/L groups, and changes in the bone geometry were observed in these animals. The results clearly revealed that chronic, even low-level, exposure to Cd results in demineralization and weakening of the femur. The femoral neck seems to be more vulnerable than the diaphysis to failure from Cd. We conclude that environmental exposure to Cd may be an important risk factor for femoral neck fracture. The results were in small part presented at the 31st European Symposium on Calcified Tissues, Nice, France, 5–9 June 2004, with abstract published in Calcif Tissue Int 2004;74 (Suppl. 1):S68. An erratum to this article is available at .     

辛伐他汀对老年去卵巢大鼠骨量丢失的治疗作用

目的观察辛伐他汀对老年去卵巢大鼠骨量丢失的治疗作用。方法10月龄SD大鼠行双侧卵巢切除术,术后2个月开始用药物治疗,用药2个月后用骨组织形态计量学方法测定大鼠第四腰椎松质骨静态、动态参数,大鼠第五腰椎体应用骨生物力学方法作椎体压缩试验。结果辛伐他汀使去卵巢大鼠骨小梁面积(%Tb.Ar)增加不明显,与去卵巢组相比,差异无统计学意义;但辛伐他汀可改善去卵巢大鼠椎骨的生物力学状况,表现在能使去卵巢大鼠的破坏载荷和破坏应力增加。结论辛伐他汀对老年去卵巢大鼠椎骨的生物力学状况有改善作用。     

The Less Potent Estrogenic Effect of Tamoxifen on Bone in Ovariectomized Rats With Established Osteopenia

The longitudinal effects of tamoxifen (TAM) treatment on bone metabolism, spinal bone mineral density (BMD), and bone mineral content (BMC) were compared with those of estrogen in ovariectomized (OVX) rats with established osteopenia. The 6-month-old rats were divided into Sham (n = 8) and OVX (n = 24) groups. First, the OVX rats were allowed to lose bone for 6 weeks. Six weeks after ovariectomy they were divided into three groups: (1) OVX rats treated with solvent vehicle (OVX+Vehicle), (2) OVX rats injected with TAM subcutaneously six times a week at a dosage of 1.0 mg/kg body weight (OVX+TAM), (3) OVX rats injected with 17-β estradiol subcutaneously six times a week at a dosage of 0.1 mg/kg body weight (OVX+ET). The longitudinal effects of TAM and estrogen on bone were studied by dual energy X-ray absorptiometry (DXA) and biochemical markers including urinary pyridinoline (Pyr) and deoxypyridinoline (Dpyr). Ovariectomy resulted in a significant increase in urinary Pyr, Dpyr, and a significant decrease in spine BMD and BMC. TAM treatment completely inhibited the further bone loss in OVX rats with established osteopenia, however, estrogen increased spine BMD and BMC significantly compared with OVX+Vehicle, OVX+TAM, and baseline of treatment. Both TAM and estrogen treatment decreased urinary Pyr and Dpyr significantly in OVX rats. Our findings indicate that TAM acts as an estrogen agonist with respect to effects on spine BMD, BMC, and bone resorption in OVX rats with established osteopenia, but fails to restore spine BMD and BMC to the extent observed with estrogen in this study.     

The development of femoral osteopenia in ovariectomized rats is not reduced by high intensity treadmill training: A mechanical and densitometric study

The effect of treadmill running on the development of osteopenia was investigated in adult ovariectomized (OVX) rats compared with sedentary OVX and sedentary sham-operated rats. The rats were 3 months old with a mean weight of 214 g. OVX rats were fed a low calcium diet (0.01%), and the sham rats received the normal diet (1.1% calcium). The training consisted of treadmill running at a speed of 27 m/minute for 1 hour 5 out of 7 days during a period of 8^1/2 weeks. The weight gain was higher in the sedentary OVX (108 g) than in the training OVX (62 g) and sham-operated rats (61 g) (P<0.001). Comparing the two OVX groups, training had no significant effects on the development of femoral osteopenia as assessed by mechanical testing of the femoral shaft and neck, and by bone mass measurements by dual energy X-ray absorptiometry (DXA) or by ashing. Comparing all three groups bone mineral content (BMC) and bone mineral density (BMD) were reduced by more than 40% in both the OVX groups compared with the sham-operated rats (P<0.001). Ash weight and calcium content were reduced by approximately 40% in both OVX groups. Femoral volume and length were 10% higher in the sedentary OVX animals compared with the trained (P<0.05), indicating that the training had had a negative effect on the growth changes induced by ovariectomy. The fracture strength of the femoral shaft was reduced by 26% and 22% in the trained and sedentary OVX rats, respectively compared with the sham-operated group (P<0.001). The fracture strength of the femoral neck was reduced by 18% and 15% but due to one very weak neck in the sham group, this difference was not significant. The accuracy of BMC measured by DXA was high when compared with calcium content (r=0.98, P<0.001) and ash weight (r=0.96, P<0.001). DXA underestimated the BMC of the femur by 27% as compared with ash weight. BMC was also highly correlated to fracture strength of the shaft (r=0.85, P<0.001), but not to fracture strength of the neck. This study shows that high intensity training had no positive effect on the development of osteopenia in rats, and we have also validated and found DXA to be a precise and useful tool for experimental studies on osteoporosis in the rat.     

Osteoclastogenesis Inhibitory Factor/Osteoprotegerin Reduced Bone Loss Induced by Mechanical Unloading

Skeletal unloading resulting from space flight and prolonged immobilization causes bone loss. Such bone loss ostensibly results from a rapid increase in bone resorption and subsequent sustained reduction in bone formation, but this mechanism remains unclear. Osteoclastogenesis inhibitory factor/osteoprotegerin (OCIF/OPG) is a recently identified potent inhibitor of osteoclast formation. We studied effects of OPG administration on tail-suspended growing rats to explore the therapeutic potential of OPG in the treatment and prevention of bone loss during mechanical unloading, such as that which occurs during space flight. Treatment with OPG in tail suspension increased the total bone mineral content (BMC g) of the tibia and femur and the total bone mineral density (BMD g/cm²) of the tibia. Moreover, treatment with OPG prevented reduction not only of BMC and BMD, but also of bone strength occurring through femoral diaphysis. Treatment with OPG in tail-suspended rats improved BMC, BMD and bone strength to levels of normally loaded rats treated with vehicle. Treatment with OPG in normally loaded rats significantly decreased urinary excretion of deoxypyridinoline, but the effect of OPG in tail suspension was unclear. These results indicate that OPG may be useful in inhibiting bone loss-engendered mechanical unloading.     

Comparable Effects of Alendronate and Strontium Ranelate on Femur in Ovariectomized Rats

This study compared the effects of alendronate (ALN) and strontium ranelate (SR) on bone mineral density (BMD), bone histomorphometry, and biomechanics in ovariectomized (OVX) rats. We randomly assigned 48 3-month-old female Sprague–Dawley rats to four groups: sham, OVX, ALN, and SR. Rats in the OVX, ALN, and SR groups received bilateral OVX. Rats in the ALN and SR groups were orally administrated ALN (7 mg/kg/week) and SR (500 mg/kg/day). Rats in the sham and OVX groups were treated with saline. All treatments continued for 12 weeks. Femoral BMD examination, distal femoral bone histomorphometry analysis, and biomechanical tests at the femoral diaphysis and metaphysis were performed to evaluate the effects of treatments in OVX rats. Results showed that both ALN and SR significantly increased femoral BMD (total femur, diaphyseal BMD, and distal metaphyseal BMD), distal femoral bone histomorphometric parameters (BV/TV, Tb.N, and Tb.Th), and femoral biomechanical parameters (maximum load, failure load, stiffness) compared with the OVX group (P < 0.05). No differences were found between ALN and SR in increasing femoral BMD, distal femoral bone histomorphometric parameters (BV/TV, Tb.N, and Tb.Th), and femoral diaphysis biomechanical parameters (maximum load, failure load, stiffness) (P > 0.05). The SR group was inferior to the ALN group in femoral metaphysis biomechanical parameters (P < 0.05). In conclusion, ALN (7 mg/kg/week) and SR (500 mg/kg/day) have similar effects by increasing BMD, distal femoral bone histomorphometric parameters, and femoral metaphysis biomechanical properties. Although ALN has greater effects than SR on distal femoral metaphysis biomechanical properties, in general, ALN and SR have comparable effects on the femur in OVX rats.     

Minodronic acid ameliorates vertebral bone strength by increasing bone mineral density in 9-month treatment of ovariectomized cynomolgus monkeys

The effect of treatment for 9 months with minodronic acid, a nitrogen-containing bisphosphonate, on vertebral mechanical strength was examined in ovariectomized (OVX) cynomolgus monkeys. Forty skeletally mature female monkeys were randomized into four OVX groups and one sham group (n = 8) based on lumbar bone mineral density (BMD). OVX animals were treated orally with 15 and 150 μg/kg QD of minodronic acid or 500 μg/kg QD alendronate as a reference drug. Measurements of bone turnover markers and lumbar BMD were conducted at 0, 4 and 8 months. Measurements of bone mechanical strength and minodronic acid concentration in vertebral bodies were also performed. OVX resulted in a decrease in lumbar BMD and an increase in bone turnover markers at 4 and 8 months, compared to the sham group, and the ultimate load on the lumbar vertebra was decreased in OVX animals. Minodronic acid and alendronate prevented the OVX-induced increase in bone turnover markers and decrease in lumbar BMD. Minodronic acid at 150 μg/kg increased the ultimate load on lumbar vertebra compared to untreated OVX animals. Regression analysis revealed that the ultimate load was correlated with lumbar BMD and bone mineral content (BMC), and most strongly with the increase in lumbar BMD and BMC over 8 months. In a separate analysis within the sham-OVX controls and minodronic acid and alendronate treatment groups, the ultimate loads were also correlated with BMD and BMC. The load-BMD (BMC) correlation in the minodronic acid group showed a trend for a shift to a higher load from the basal relationship in the sham-OVX controls. These results indicate that treatment with minodronic acid for 9 months increases vertebral mechanical strength in OVX monkeys, mainly by increasing BMD and BMC.     

中等强度跑台运动对去卵巢大鼠后肢骨骨矿物含量和骨密度的双重调节作用

目的 观察中等强度跑台运动对去卵巢大鼠后肢骨骨矿物含量(BMC)和骨密度(BMD)的影响.方法 将60只3月龄未经产雌性SD大鼠按体重随机分为假手术、去卵巢静止、去卵巢运动Ⅰ、去卵巢运动Ⅱ、去卵巢运动Ⅲ和去卵巢运动Ⅳ 6个组.各运动组经1周的跑台适应训练后,按实验设计分别进行为期14周的正式跑台训练.实验结束时,腹主动脉取血处死大鼠,双能χ-射线骨密度仪检测右侧游离股骨和胫骨的BMC和BMD.结果 ①与假手术组相比,去卵巢静止组股骨近端和远端以及胫骨近端BMC和BMD显著下降,但股骨中段以及胫骨中段和远端BMC和BMD无显著变化.②与去卵巢静止组相比,去卵巢运动Ⅰ组股骨近端和远端BMC显著增加,股骨中段以及胫骨3个部位BMC均无显著变化;去卵巢运动Ⅱ组和Ⅲ组股骨和胫骨3个部位BMC 均无显著变化;去卵巢运动Ⅳ组股骨3个部位BMC均无显著变化,而胫骨3个部位BMC均显著下降.③与去卵巢静止组相比,去卵巢运动Ⅰ组股骨近端和远端以及胫骨近端BMD 显著增加, 而股骨中段和胫骨中段和远端BMD无显著变化;去卵巢运动Ⅱ组和Ⅲ组股骨和胫骨任何部位BMD均没有显著变化;去卵巢运动Ⅳ组股骨3个部位BMD无显著变化,而胫骨3个部位BMD却显著下降.结论 较低中等强度跑台运动能减缓去卵巢大鼠股骨近端和远端骨矿物含量和骨密度的下降;而较高中等强度跑台运动却能加速去卵巢大鼠胫骨近端骨矿物含量和骨密度的下降.     

鹿瓜多肽注射液对去势大鼠骨密度和骨力学性能的影响

目的研究鹿瓜多肽注射液对去卵巢大鼠骨骼生物力学性能的影响。方法 3个月龄清洁级雌性Wistar大鼠27只,随机分为假手术（sham group,SHAM）组、去势（ovariectomized,OVX）组、去势＋鹿瓜多肽（cervus and cu-cumis polypeptide,CCP）组,每组9只。OVX＋CCP组大鼠于术后第1天开始按0.6 mL/（kg.d）肌注鹿瓜多肽注射液,术后12周处死所有大鼠,取出股骨及腰椎标本,双能X线吸收仪测量各组大鼠股骨近端、股骨干及全腰椎的骨密度。应用INSTRON 3367电子拉伸试验机检测股骨近端、股骨干和L5的生物力学性能。结果 a）OVX组与SHAM组相比较,大鼠股骨和腰椎最大载荷无明显下降（P〉0.05）,但极限强度明显下降（P〈0.01）;与OVX组相比,OVX＋CCP组的最大载荷无明显增加（P〉0.05）,但极限强度显著高于去势组（P〈0.01）;OVX＋CCP组与SHAM组比,上述检测指标间无统计学差异（P〉0.05）;b）与SHAM组相比,OVX组股骨近端、股骨干及全腰椎的骨密度明显降低（P〈0.01）;与OVX组相比,OVX＋CCP组各部位骨密度明显高于OVX组（P〈0.01）;OVX＋CCP组与SHAM组比,两者各部位骨密度无明显差异（P〉0.05）。结论鹿瓜多肽注射液能保护去势大鼠骨密度和骨骼内在生物力学性能。     

低强度脉冲电磁场对去卵巢大鼠不同部位骨密度的影响

目的 探讨低强度脉冲电磁场(PEMFs)对去势雌性大鼠不同部位骨密度的影响.方法 30只10月龄雌性SD大鼠随机分为3组:一组去势造模(造模组),另一组行假手术(空白组),第三组去势造模后暴露于50 Hz、0.16 mT的磁场环境下60 min/d,共90天(磁疗组).实验期间动态观察大鼠全身及颅骨骨密度,期满处死后测定血清雌二醇水平及骨密度.结果 ①空白组雌激素水平和子宫系数均显著高于其他两组(P<0.01);②至60天时,空白组、磁疗组的颅骨骨密度显著高于造模组(P<0.05),全身骨密度在90天时才出现统计学意义(P<0.05);③与空白组和磁疗组相比,造模组椎体骨密度(P<0.01)比腰椎骨密度(P<0.05)差异更显著,磁疗组股骨骨密度虽较造模组有所上升但差异未达到统计学意义.结论 全身骨密度与颅骨骨密度结合可有效评估大鼠活体骨密度动态变化;PEMFs对因去势造成的骨密度下降有明显抑制作用,且对不同部位骨密度影响程度不同;采用去椎弓的单一椎体为骨密度衡量点能更为敏感的反映治疗效果.     

Restoration of ovariectomy-induced osteopenia by nitroglycerin

Nitric oxide (NO) is known to inhibit osteoclastic bone resorption. Previously, we demonstrated that the NO donor nitroglycerin (NG) prevented ovariectomy (OVX)-induced bone loss. The current study shows that NG restores ovariectomy-induced osteopenia. Twenty-four female Sprague-Dawley rats, 36 weeks of age, underwent OVX, and a further six rats were sham-operated. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometric (DXA) scanning prior to OVX, at 6 weeks postsurgery, and at 6 weeks posttreatment. OVX rats were then assigned to four groups and treated with either (1) vehicle, (2) 17-β-estradiol, (3) NG (0.2 mg/kg/day), or (4) a combination of estrogen and NG (n = 6/group). During the first 6-week post-OVX period, there was a significant decrease in the BMD in all ovariectomized (OVXed) rats (−11.0%, P < 0.001). There were no significant changes in BMD during the entire 12-week period in sham-operated rats. During the second 6-week period (after developing bone loss), there was no further significant loss of BMD in OVXed controls. BMD loss and loss of femur weight produced by OVXed were restored by treatment with estrogen, NG, or the two agents together during the second 6-week period (P < 0.01). The effects of estrogen and NG together, however, were not additive. The BMD of rats treated with NG alone, at 12 weeks, was similar to that of animals treated with estrogen alone or with estrogen and NG, and was comparable to that of sham-operated rats. The increased urinary excretion of deoxypyridinolines caused by OVX was negated by estrogen, NG, and estrogen together with NG (P < 0.01). In contrast to estrogen, NG did not decrease the post-OVX-induced increase of serum osteocalcin levels, suggesting that NG may also have a positive effect on bone formation. In summary, the results suggest that the NO donor, NG, reverses the OVX-induced bone loss in rats, and these effects are likely due to decreased bone resorption and, perhaps, increased bone formation. Received: 24 December 1998 / Accepted: 1 July 1999     

麝香乌龙丸对卵巢切除大鼠股骨骨折愈合的实验研究

目的研究麝香乌龙丸对卵巢切除大鼠股骨干骨折愈合的作用。方法将30只雌性、12周龄Sprague-Dawley大鼠分成3组假手术组(Sham F V)、卵巢切除 骨折 生理盐水对照组(OVX F V)、卵巢切除 骨折 麝香乌龙丸给药组(OVX F M),每组10只大鼠。所有需制造骨折的大鼠均采用右股骨中段横行骨折,髓内针固定;麝香乌龙丸给药组采用大鼠灌胃给药(1.2g.kg-1.d-1),于术后4周杀死,取大鼠右侧股骨标本;分别进行CR摄片、组织形态学染色,并应用双能X线骨密度仪(DEXA)测量右股骨整体骨密度(tBMD)、远段骨密度(dBMD)和中段骨密度(mBMD)以及BMP-2免疫组化观察,并应用病理图像分析仪对BMP-2免疫组化进行光密度测定。结果麝香乌龙丸给药组与OVX F V比较,前者骨痂mBMD和BMP-2的表达显著增高,骨小梁增宽、排列较整齐,板层骨形成,软骨组织可见。结论麝香乌龙丸对OVX大鼠股骨骨折有明显促进骨折愈合的作用,并加快编织骨向板层骨的演变过程,这与BMP-2的表达有明显相关性。