尼尔雌醇对去卵巢大鼠胫骨骨重建的影响

目的　探讨尼尔雌醇防治绝经后骨质疏松 (PMO)的作用机制。方法　雌性Wistar大鼠30只 ,随机分成假手术组、去卵巢组和尼尔雌醇治疗 (N)组。假手术组进行假手术 ,其余 2组切除卵巢制备PMO模型 ,N组使用尼尔雌醇治疗 3个月。各组动物处死后 ,取一侧胫骨提取总RNA ,逆转录 聚合酶链反应 (RT PCR)检测白细胞介素 (IL 6 )mRNA表达情况。另一侧用骨形态计量学方法研究去卵巢大鼠胫骨干骺端对尼尔雌醇的治疗反应 ,包括静力学参数 :(1)骨小梁体积 (TBV)占全部骨组织体积 (TTV)的百分比 (TBV/TTV) ;(2 )骨小梁表面与其体积之比 (S/V) ;(3)TBV占海绵骨 (SBV)体积的百分比 (TBV/SBV) ;(4 )平均骨小梁板厚度 (MTPT) ;(5 )平均骨小梁板密度 (MTPD) ;(6 )平均骨小梁板间隙 (MTPS) ;(7)平均骨皮质厚度 (MCW)。动力学参数 :(1)骨小梁类骨质表面占骨小梁表面的百分比 (TOS) ;(2 )平均类骨质宽度 (MOSW) ;(3)四环素单标记线占骨小梁表面的百分比 [Sfract(s) ];(4 )四环素双标记线占骨小梁表面的百分比 [Sfract(d) ];(5 )四环素单标记线的 1/ 2和双标记线之和占骨小梁表面的百分比 [Sfract(s/ 2 d) ];(6 )四环素双标记线间的平均距离 (DDL) ;(7)矿化沉积率 (MiAR) ;(8)矿化延迟时间 (MLT) ;(9)组织水平的骨形成率 (Svf) ;     

Pueraria mirifica, a phytoestrogen-rich herb, prevents bone loss in orchidectomized rats

OBJECTIVE: Estrogens and estrogen-like substances have been reported to play an important role in male bone homeostasis and to prevent bone loss. Pueraria mirifica (Leguminosae), a Thai herbal plant, containing a high amount of phytoestrogens was a choice of interest for this study. We examined the effects of crude P. mirifica on bone loss and influences on reproductive organs in male rats. METHODS: Using fully mature and orchidectomized (ORX) rats, the effects of 0, 10, 100 and 1000 mg/kgB.W./day of P. mirifica and 0.1mg/kg B.W./day of 17 alpha-ethinylestradiol (a positive control) were evaluated on bone mineral density (BMD) and bone mineral content (BMC) measured with a peripheral Quantitative Computerized Tomography (pQCT) densitometry. RESULTS: Bone loss in trabecular and cortical bones of the various sites of axial bone (fourth lumbar vertebral body) and long bones (tibia and femur) after ORX was dose-dependently prevented by P. mirifica. The effects were specific on bone types and sites. The weights of the accessory sex organs, seminal vesicle and ventral prostrate gland, which significantly decreased after 3-month of ORX, were not altered by P. mirifica. CONCLUSION: The results suggest that P. mirifica treatment may be useful to prevent an osteoporosis in elderly hypogonadism subjects without influences on reproductive organs.     

去卵巢大鼠骨密度变化与骨髓组织血管生成的关系

目的： 探讨去卵巢大鼠骨密度变化与骨髓组织血管生成的关系。方法：30只SD雌性大鼠随机分为去卵巢组（OVX）和假手术组（sham）,分别在4周、8周和12周处死。取左侧股骨测量骨密度(BMD)。右侧远端股骨干骺端松质骨甲醛固定,EDTA-Na2脱钙。常规脱水、石蜡包埋、切片。行苏木素－伊红染色用于观察骨髓组织病理改变,用CD34标记血管内皮细胞观察微血管密度(MVD),采取大鼠腹主动脉血进行血管内皮生长因子(VEGF)测定。结果： 大鼠去卵巢8周后BMD明显低于假手术组, 提示骨质疏松模型建立,此时,骨髓造血组织容量减少,脂肪组织容量增高,与假手术组比较均有显著差异（P<0.01）,骨髓组织MVD与假手术组比略有减少。12周后,上述改变更为明显。同时,骨小梁容量减少,骨髓组织MVD明显减少（P<0.05）,且显示MVD与BMD、造血组织容量和骨小梁容量呈正相关,与脂肪组织容量呈负相关。但血浆VEGF含量测定OVX组与sham组间无明显差异,与骨髓组织各形态指标亦无相关性。结论：去卵巢大鼠在骨量丢失和造血组织容量减少的同时伴有骨髓组织MVD减少, 为骨质疏松症采用促微血管增生治疗提供了实验依据。     

Evaluation of the antiosteoporotic potential of Tinospora cordifolia in female rats

The available courses of therapy to osteoporosis in menopausal women are limited by several side effects generated. A need therefore arises to explore herbal alternatives that are effective and safe. OBJECTIVE: Present animal studies were conducted to investigate the potential of Tinospora cordifolia (TC) ethanolic stem extract as an antiosteoporotic agent. METHODS: Three-month-old female Sprague-Dawley rats were either ovariectomized (ovx) or sham operated and treated with vehicle (benzyl benzoate:castor oil; 1:4), E(2) (1 microg/day) or TC (10, 50, 100 mg/kg b.wt) subcutaneously for 4 weeks. At the end of experiment bone mineral density of tibiae was measured by quantitative computer tomography. Serum was analyzed for the activity of alkaline phosphatase and levels of osteocalcin, cross-laps and lipids. Uterus and mammary gland were processed for histological studies. RESULTS: Ovx rats treated with TC (10 mg/kg b.wt) showed an osteoprotective effect as the bone loss in tibiae was slower than ovx controls. Serum osteocalcin and cross-laps levels were significantly reduced. All the above effects of TC were much milder than those produced by E(2). Alkaline phosphatase activity was higher in TC treatment groups. Total cholesterol and LDL levels remained unaltered but HDL levels were significantly lowered with TC (50 mg/kg b.wt) treatment. Uterus and mammary gland showed no signs of proliferation after treatment with TC extract. CONCLUSION: TC extract showed estrogen like effects in bone but not in reproductive organs like uterus and mammary gland. Thus, this study demonstrates that extract of T. cordifolia has the potential for being used as antiosteoporotic agent.     

毛蕊异黄酮防治去卵巢大鼠骨质疏松的实验研究

目的复制去卵巢大鼠骨质疏松动物模型,观察不同剂量的毛蕊异黄酮对去卵巢大鼠骨质疏松的防治作用。方法 50只SD雌性大鼠,随机分成五组：设一假手术组;腹腔手术切除大鼠双侧卵巢,分为阴性对照组、毛蕊异黄酮低、高剂量组和雌激素对照组,分别给予标准饲料和不同剂量受试物,12周后进行骨密度、骨组织形态计量、生物力学测定,与雌激素对照,观察给与毛蕊异黄酮对绝经后骨质疏松的防治作用。结果大鼠去卵巢后骨密度显著下降,股骨的力学性能有较大变化,弯曲强度和弯曲弹性模量明显降低。给予毛蕊异黄酮后,可使骨密度显著提高（P〈0.01）,存在一定的剂量-效应关系,同时弯曲强度和弯曲弹性模量明显增加,但均低于雌激素对照组。结论通过去卵巢手术,成功建立绝经后骨质疏松动物模型;毛蕊异黄酮对去卵巢大鼠具有显著的骨保护效应,并存在一定的剂量效应关系,其作用弱于雌激素。     

去势大鼠骨量丢失过程中骨髓间充质干细胞的增殖分化功能

目的: 研究骨髓间充质干细胞(BMSCs)增殖分化功能在去势大鼠骨质疏松发病过程中对骨量丢失的作用。方法: 选用10周龄健康雌性SD大鼠行双侧卵巢切除术(OVX),建立骨质疏松症(OP)的动物模型;选用同一批次、周龄相同、体重相近的健康雌性SD大鼠行双侧卵巢附近脂肪组织部分切除术,建立假手术(sham)组,假手术大鼠组(sham group)。采用离心法、贴壁法和有限稀释法分离、培养、纯化大鼠BMSCs,体外培养传至3~4代后用于实验:流式细胞术进行BMSCs表型鉴定;克隆形成实验检测BMSCs增殖状况;MTT法测定BMSCs生长曲线;成脂诱导后脂滴油红O染色法检测比较2组大鼠BMSCs成脂能力;成骨诱导后钙化结节茜素红染色法检测比较2组大鼠BMSCs成骨能力;RT-PCR法检测大鼠BMSCs成骨相关蛋白Runx2、骨钙素(OCN)和骨桥蛋白(OPN)mRNA的表达。结果: 与sham组大鼠BMSCs相比,OVX组大鼠BMSCs克隆形成能力减弱,增殖能力降低,成脂向分化增强,成骨向分化减弱(P<0.05)。结论: 去卵巢骨质疏松大鼠BMSCs增殖及成骨分化减弱,成脂分化增强;这导致去势大鼠快速的骨量丢失,在去势大鼠OP发病过程中发挥着重要作用。     

去卵巢大鼠不同时期骨量、骨转换指标、雌激素水平的变化规律及相关性

背景：目前对去卵巢大鼠的研究较多,而对不同时间点大鼠骨量、骨转换指标、雌激素水平的变化规律及各因素的相关性研究报道较少。 目的：分析去卵巢大鼠不同时期骨量、骨转换指标、雌激素水平的变化规律并探讨其相关性。 方法：34只3月龄雌性SD大鼠,随机分为基线组、假手术组和去卵巢组。实验开始先将基线组处死,假手术组及去卵巢组于术后第4,8,12周分次处死。双能X射线吸收法(DXA)测定L1-3及股骨不同分区(头颈部R1区、转子部R2区、股骨干R3区、股骨整体R4区)的骨矿含量、骨密度、骨面积;酶联免疫吸附法(ELISA)检测血清Ⅰ型前胶原氨基端原肽、Ⅰ型胶原羧基端肽及雌激素水平。对大鼠体质量、离体骨密度、Ⅰ型前胶原氨基端原肽、Ⅰ型胶原羧基端肽、雌激素水平、月龄间的相关性进行分析。 结果与结论：①去卵巢后4周去卵巢组离体腰椎及股骨骨矿含量、骨密度均较基线组、假手术组明显降低(P < 0.05),第8,12周时均显著改善(P < 0.05),腰椎、股骨各区域骨量丢失幅度最大的为L1及股骨转子区。       ②去卵巢后4周去卵巢组血清Ⅰ型前胶原氨基端原肽、Ⅰ型胶原羧基端肽水平较基线组、假手术组均显著升高(P < 0.05),第8,12周差异无显著性意义。③去卵巢组第8,12周血清雌激素较假手术组及基线组明显降低(P < 0.01,P < 0.05)。④月龄与大鼠体质量、腰椎及股骨骨密度呈正相关,Ⅰ型前胶原氨基端原肽、Ⅰ型胶原羧基端肽与腰椎及股骨骨密度呈负相关(P < 0.01)。提示去卵巢后大鼠腰椎、股骨骨量变化呈先快速降低、再缓慢回升的趋势,其中L1及股骨转子部受影响最大;骨转换指标在去卵巢后显著加快、后期逐渐回归正常;雌激素水平变化规律为第1个月先升高、后期快速降低;体质量、骨转换指标及雌激素水平与骨量密切相关。  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;组织工程全文链接：     

强骨康疏胶囊对去卵巢骨质疏松大鼠骨细微结构及骨代谢的影响

目的:观察强骨康疏胶囊对去卵巢骨质疏松大鼠的骨密度、OPG及RANKL蛋白表达、骨组织形态计量学参数及骨组织细微结构的影响。方法:制备去卵巢骨质疏松大鼠模型后,分组:正常对照组、模型空白组、中药低剂量预防组、中药高剂量预防组、雌激素预防组。给药1月后,检测各组股骨骨密度值,显微镜下观察股骨骨小梁的结构变化,并检测骨组织形态计量学参数。采用免疫组织化学染色法检测大鼠股骨OPG及RANKL蛋白表达。结果:模型空白组大鼠股骨骨密度减少,骨小梁厚度、面积、面积百分数均减少,骨小梁间距增大,股骨OPG蛋白平均光密度值显著降低,RANKL蛋白平均光密度值明显增高;雌激素预防组、中药低剂量组、中药高剂量组对上述指标均有明显改善。结论:强骨康疏胶囊能有效提高骨量,维持骨小梁立体空间结构,改善大鼠股骨远端松质骨的显微结构,能够提高骨OPG蛋白表达及抑制RANKL蛋白表达。     

Preventive effects of Pueraria mirifica on bone loss in ovariectomized rats

OBJECTIVE: Effects of Pueraria mirifica on bone loss in fully mature ovariectomized rats are examined. METHODS: Two series of experiments were performed. In the first series, rats were kept with their ovaries intact and divided into two groups; initial control (IC) and sham control (SH). The IC rats were sacrificed on day 1 and their data were kept as baseline control. The SH rats were subjected to sham operation on day 0 and gavaged daily with distilled water for 90 days. In the second series, rats were subjected to ovariectomy, divided into five groups and gavaged daily with 0.1mg/kg B.W./day of 17-alpha-ethinylestradiol (EE), 0, 10, 100 and 1000mg/kg B.W./day of P. mirifica (P0, P10, P100 and P1000, respectively) for 90 days. Changes of bone mineral density and bone mineral content were measured using peripheral Quantitative Computerized Tomography. RESULTS: Bone loss was significantly induced by ovariectomy and it was dose-dependently prevented by P. mirifica treatment for 90 days. The preventive effects of P. mirifica on bone loss depended on bone types (axial or long bone), bone sites (metaphysis or diaphysis), and bone compartments (trabecular and cortical). At P100 and P1000, bone loss was completely prevented both in trabecular bone mineral density and content. The effects of P. mirifica were, as expected, comparable to that in the EE group. CONCLUSION: These results suggest that P. mirifica may be applicable to treat the osteoporosis in menopausal women; however, an undesirable side effect on stimulating reproductive organs should be concerned.     

康力龙对类固醇性大鼠骨质疏松骨密度和生物力学的影响

目的　从生物力学和骨矿含量测定角度研究康力龙对类固醇性大鼠骨代谢的影响。方法　采用 3月龄雄性SD大鼠 2 8只 ,随机分为基础对照组、年龄对照组、激素模型组和康力龙预防组。后两组给醋酸泼尼松 4 5mg·kg-1,ig ,2次 /周 ;预防组还给康力龙 0 5mg·kg-1·d-1,ig。 3个月后取股骨和第 5腰椎行骨密度测定 ,再行扭转、3点弯曲和压缩试验。结果　与年龄对照组比较 ,激素模型组股骨和第 5腰椎的总骨密度减少了 14 6 4 % (P <0 0 1) ;股骨干在 3点弯曲试验时所承受的载荷减少了17 1% (P <0 0 5 ) ;其余的力学参数都出现减少的趋势。与激素模型组比较 ,康力龙预防组股骨和第 5腰椎的总骨密度有所增加 ;股骨扭转角度明显增加 72 5 % (P <0 0 5 ) ,其余的力学参数都出现增加的趋势。结论　长期使用糖皮生激素 (GC) ,会使大鼠皮质骨和松质骨的骨密度和力学性能下降 ,从而易致骨折 ;应用康力龙则能阻止GC所致骨量丢失 ,还能增加其力学性能。     

Piper sarmentosum enhances fracture healing in ovariectomized osteoporotic rats: a radiological study

INTRODUCTION:

Osteoporotic fractures are common during osteoporotic states. Piper sarmentosum extract is known to possess antioxidant and anti-inflammatory properties.

OBJECTIVES:

To observe the radiological changes in fracture calluses following administration of a Piper sarmentosum extract during an estrogen-deficient state.

METHODS:

A total of 24 female Sprague-Dawley rats (200-250 g) were randomly divided into 4 groups: (i) the sham-operated group; (ii) the ovariectomized-control group; (iii) the ovariectomized + estrogen-replacement therapy (ovariectomized-control + estrogen replacement therapy) group, which was supplemented with estrogen (100 µg/kg/day); and (iv) the ovariectomized + Piper sarmentosum (ovariectomized + Piper sarmentosum) group, which was supplemented with a water-based Piper sarmentosum extract (125 mg/kg). Six weeks after an ovariectomy, the right femora were fractured at the mid-diaphysis, and a K-wire was inserted. Each group of rats received their respective treatment for 6 weeks. Following sacrifice, the right femora were subjected to radiological assessment.

RESULTS:

The mean axial callus volume was significantly higher in the ovariectomized-control group (68.2±11.74 mm³) than in the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups (20.4±4.05, 22.4±4.14 and 17.5±3.68 mm³, respectively). The median callus scores for the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups had median (range, minimum - maximum value) as 1.0 (0 - 2), 1.0 (1 - 2) and 1.0 (1 - 2), respectively, which were significantly lower than the ovariectomized-control group score of 2.0 (2 - 3). The median fracture scores for the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups were 3.0 (3 - 4), 3.0 (2 - 3) and 3.0 (2 - 3), respectively, which were significantly higher than the ovariectomized-control group score of 2.0 (1 - 2) (p<0.05).

CONCLUSION:

The Piper sarmentosum extract improved fracture healing, as assessed by the reduced callus volumes and reduced callus scores. This extract is beneficial for fractures in osteoporotic states.     

雌性去卵巢大鼠体脂、瘦素与骨密度关系的初步探讨

本文旨在探讨体脂与骨量的关系,以及调节体脂的瘦素对骨的作用。选用6月龄雌性Wistar大鼠40只,随机分为两组,一组切除双侧卵巢,另一组行假手术。饲养2月后采用ELISA检测血清中瘦素浓度,检测大鼠体质量、腹腔内脂肪含量,DEXA测定大鼠股骨骨密度(BMD)。结果提示大鼠体质量在去卵巢组增加明显(P<0.05),腹腔内脂肪量在去卵巢后增加不明显(P=0.499),脂肪细胞分泌的瘦素两组之间没有差异(P=0.166),去卵巢组单位体质量的骨矿含量(BMC)较假手术组明显降低(P=0.003)。第8周体质量在假手术组与单位体质量BMC负相关,在去卵巢组与BMD正相关,假手术组腹腔内脂肪含量及瘦素浓度与单位体质量的BMC呈负相关关系。因此,体脂、瘦素与单位体质量BMC相关。     

Serum leptin levels,bone mineral density and osteoblast alkaline phosphatase activity in elderly men and women

Although primarily secreted by adipose cells, leptin, a polypeptide hormone that influences body weight, satiety and lipid metabolism, and its receptor are also expressed in human osteoblasts. Leptin plays a role in the central, hypothalamic modulation of bone formation, as well as locally within the skeleton by enhancing differentiation of bone marrow stroma into osteoblasts and inhibiting its differentiation into osteoclasts and adipocytes. The purpose of this investigation was to compare serum leptin values in 100 postmenopausal women (age 62-97) and 31 men (age 72-92) to bone mineral density (BMD) measurements made by dual X-ray absorptiometry and additionally to biochemical markers of bone resorption and formation, including crosslinked collagen N-telopeptides (NTx), aminoterminal extension procollagen propeptides (PINP) and bone-specific alkaline phosphatase (bAP). The circulating level of leptin directly correlated with body mass index (BMI) (r=0.61-0.78, P<0.001) and was modestly, but significantly and positively associated with bAP activity (r=0.24-0.33, P<0.01) in the sera of men and women after adjustment for BMD, age and BMI. The association of circulating leptin levels with bAP, a specific marker of osteoblast activity suggests that leptin levels influence osteoblast activity in vivo in elderly women and men.     

Risk factors for bone loss in the hip of 75-year-old women: A 4-year follow-up study

Risk factors for bone loss among the elderly are largely unknown. The objective of the study was to examine longitudinal bone loss in the hip in one-hundred and sixty-two 75-year-old women. Bone mineral density (BMD, g/cm²) was measured with dual X-ray absorptiometry (DXA) at baseline and after 4 years. The relationship between changes in BMD during follow-up and the following factors; baseline BMD, baseline weight, weight change, baseline lean and fat body mass (measured with DXA), serum values of biochemical markers and hormones, nutritional and lifestyle factors according to a questionnaire was assessed.     

Triterpenoids from Cimicifugae rhizoma, a novel class of inhibitors on bone resorption and ovariectomy-induced bone loss

OBJECTIVE: Increasing research suggested that Cimicifugae rhizoma might be protective against osteoporosis. In this study, we investigated the effects of three cycloartane-type triterpenoids isolated from Cimicifugae rhizoma, cimicidol-3-O-beta-D-xyloside (1), cimicidanol-3-O-beta-D-xyloside (2) and acetylacteol-3-O-beta-d-xyloside (3) on bone resorption in vitro and bone loss in ovariectomized (OVX) mice. METHODS: The activities of the tested compounds on bone resorption were evaluated using three assays, neonatal mouse parietal bone organ culture, osteoclast-like cells (OCLs) formation and pit formation. The effects on bone mineral density (BMD) and uterine weight were examined using OVX mice. Using LC-MS/MS method, the serum concentrations of the triterpenoids were measured in mice serum collected at 0.5, 1, 3, 6 and 12h following its oral administration. RESULTS: All of the tested compounds exerted the inhibitory effects on bone resorption in bone organ culture, suppressed both of the formation and the resorbing activity of OCLs. Furthermore, a synergistic effect was observed among those compounds. In vivo studies revealed that compounds 1-3 and the mixture of compounds 1-3 prevented the bone loss in OVX mice without affecting uterine weight, and each compound was detected in the mice serum after single oral administration. CONCLUSIONS: The triterpenoids exerted the inhibitory effects on osteoclastic bone resorption through the suppression of both OCLs formation and the resorbing activity of OCLs, and also showed a significant protective effect on BMD in OVX mice. The present results might provide a new pharmacological potential for the treatment of osteoporosis.     

Association of genetic variation of the RIL gene,encoding a PDZ-LIM domain protein and localized in 5q31.1, with low bone mineral density in adult Japanese women

Twin and family studies had shown that genetic factors are important determinants of bone mass. Multiple genes might be involved. One candidate gene, the reversion-induced LIM gene (RIL), is a PDZ and LIM-domain-containing protein and has been localized within the cytokine cluster of chromosome 5 (5q31.1). In a genetic study of 370 adult Japanese women, we investigated the correlation between radial bone mineral density (BMD) and a genetic variation (−3333T→C) of the 5'-flanking region of RIL gene. A significant association was identified between the RIL variation −3333T→C and radial BMD (r=0.15, P=0.003). The variation of the RIL locus may be an important determinant of osteoporosis.     

LRP5, low-density-lipoprotein-receptor-related protein 5, is a determinant for bone mineral density

Osteoporosis is a multifactorial trait with low bone mineral density (BMD). We report results of an association study between BMD and nine candidate genes (TGFB1, TGFBR2, SMAD2, SMAD3, SMAD4, IFNB1, IFNAR1, FOS and LRP5), as well as of a case-control study of osteoporosis. Samples for the former association study included 481 general Japanese women. Among the nine candidate genes examined, only LRP5 showed a significant association with BMD. We identified a strong linkage disequilibrium (LD) block within LRP5. Of five LPR5 single nucleotide polymorphisms (SNPs) that are located in the LD block, three gave relatively significant results: Women with the C/C genotype at the c.2220C>T SNP site had higher adjusted BMD (AdjBMD) value compared to those with C/T and T/T (p=0.022); and likewise, G/G at IVS17–30G>A and C/C women at c.3989C>T showed higher AdjBMD than those with G/A or A/A (p=0.039) and with C/T or T/T (p=0.053), respectively. The case-control study in another series of samples consisting of 126 osteoporotic patients and 131 normal controls also gave a significant difference in allele frequency at c.2220C>T (²=6.737, p=0.009). These results suggest that LRP5 is a BMD determinant and also contributes to a risk of osteoporosis.     

High-impact exercise in rats prior to and during suspension can prevent bone loss

High-impact exercise has been considered an important method for treating bone lossin osteopenic experimental models. In this study, we investigated the effects ofosteopenia caused by inactivity in femora and tibiae of rats subjected to jumptraining using the rat tail suspension model. Eight-week-old female Wistar rats weredivided into five groups (n=10 each group): jump training for 2 weeks beforesuspension and training during 3 weeks of suspension; jump training for 2 weeksbefore suspension; jump training only during suspension; suspension without anytraining; and a control group. The exercise protocol consisted of 20 jumps/day, 5days/week, with a jump height of 40 cm. The bone mineral density of the femora andtibiae was measured by double energy X-ray absorptiometry and the same bones wereevaluated by mechanical tests. Bone microarchitecture was evaluated by scanningelectron microscopy. One-way ANOVA was used to compare groups. Significance wasdetermined as P<0.05. Regarding bone mineral density, mechanical properties andbone microarchitecture, the beneficial effects were greater in the bones of animalssubjected to pre-suspension training and subsequently to training during suspension,compared with the bones of animals subjected to pre-suspension training or totraining during suspension. Our results indicate that a period of high impactexercise prior to tail suspension in rats can prevent the installation of osteopeniaif there is also training during the tail suspension.     

Association of polymorphisms of paraoxonase 1 and 2 genes,alone or in combination,with bone mineral density in community-dwelling Japanese

Oxidative stress may affect cellular functions in various pathological conditions, including osteoporosis. Paraoxonase 1 confers antioxidant properties on high-density lipoprotein, with which it is associated, by reducing the accumulation of lipid peroxidation products. We have now examined whether the 584AG (Gln192Arg) and 172TA (Leu55Met) polymorphisms of the paraoxonase 1 gene and the 959GC (Cys311Ser) polymorphism of the paraoxonase 2 gene are associated with bone mineral density (BMD) in community-dwelling Japanese (1,087–1,094 women and 1,112–1,125 men). The subjects were aged 40 –79 years and were randomly recruited to a population-based prospective cohort study of aging and age-related diseases. BMD for the lumbar spine and right femoral neck was measured by dual-energy X-ray absorptiometry. Genotypes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay system. The 584AG and 172TA polymorphisms of the paraoxonase 1 gene and the 959GC polymorphism of the paraoxonase 2 gene were associated with BMD for the lumbar spine or femoral neck in postmenopausal women, with the 584GG, 172TT, and 959CC genotypes representing risk factors for reduced bone mass. None of these three polymorphisms was associated with BMD in premenopausal women or in men. Our results suggest that the paraoxonase 1 and 2 genes are candidate loci for reduced bone mass in postmenopausal Japanese women.     

不同剂量大豆异黄酮对去卵巢大鼠骨密度和血脂影响的研究

目的探讨不同剂量的大豆异黄酮对去卵巢大鼠骨密度和血脂水平的影响.方法选用43只10w龄性成熟SD雌性大鼠行去势手术,2w后采用完全随机的方法分为5组:阴性对照组(溶媒花生油灌胃)、阳性对照组(戊酸雌二醇500ng/g·BW·d)、大剂量组(大豆异黄酮2500μg/g·BW·d)、中剂量组(大豆异黄酮500μg/g·BW·d)和小剂量组(大豆异黄酮50μg/g·BW·d).分别于给药前和给药6周后测量总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDC)、低密度脂蛋白(LDL),并测量腰椎和股骨的骨密度.结果给大豆异黄酮6周后,大、中、小剂量组和阳性对照组腰椎骨密度均高于阴性对照组;大剂量纽骨密度的增加,有显著性差异(P＜0.05);中剂量组骨密度增加的程度和阳性对照组(戊酸雌二醇组)相似,但与阴性对照组比较无显著性差异(P＞0.05);大豆异黄酮对股骨骨密度无明显影响.大鼠去卵巢后TC和LDL下降,给大豆异黄酮后使TC和LDL进一步下降,以大剂量组最为显著,中剂量组的作用与阳性时照组相似,小剂量组无作用.结论大豆异黄酮具有雌激素样作用,能增加去卵巢大鼠的腰椎骨密度,进一步降低由于去卵巢引起的血清TC和LDL下降,它的作用强度与剂量呈正比.因此大豆异黄酮的作用值得进一步研究,以确定它是否具有临床价值.