Growth behavior of rat bone marrow cells on RF magnetron sputtered hydroxyapatite and dicalcium pyrophosphate coatings

The aim of this study was to evaluate the osteogenic properties of magnetron sputtered dicalcium pyrophaosphate (DCPP) and hydroxylapatite (HA) coatings. Therefore, DCPP and HA coatings were deposited on grit-blasted titanium discs. The substrates were used as-prepared or received an additional heat treatment which changed the amorphous coating structure to a crystalline structure. Subsequently, rat bone marrow stromal cells were cultured for 1-24 days on the various substrates. DNA and alkaline phosphatase activity was determined after 1, 3, 5, 8, and 12 days of incubation. Osteocalcin expression was evaluated after 8, 12, 16, and 24 days of incubation. Scanning electron microscopical analysis of cell morphology and coating characteristics was done after 8 and 16 days of incubation. All assays were done in duplicate and in each assay all specimens were present in fourfold. Results demonstrated that the cells did not proliferate and differentiate on all amorphous coatings. SEM revealed that the amorphous coatings showed significant dissolution. On the crystalline DCPP and HA coatings an increase in DNA and alkaline phosphatase activity was seen starting at day 8 of incubation. Osteocalcin expression on the crystalline coatings started to increase at day 16 of incubation. SEM showed that the growth and differentiation of the cells was associated with extensive collagen fiber formation and surface mineralization in the form of globular accretions. Further, statistical testing revealed that proliferation and differentiation of the rat bone marrow stromal cells started significantly earlier on the crystalline HA coatings than that on the crystalline DCPP coatings. These results demonstrate that the rat bone marrow stromal cells proliferated and differentiated only on crystalline magnetron sputtered DCPP as well as HA coatings, which warrants the further in vivo analysis of the bone healing supporting properties of these coatings.     

Glucosamine and chondroitin sulfate association increases tibial epiphyseal growth plate proliferation and bone formation in ovariectomized rats

OBJECTIVE:The growth plate consists of organized hyaline cartilage and serves as a scaffold for endochondral ossification, a process that mediates longitudinal bone growth. Based on evidence showing that the oral administration of glucosamine sulfate (GS) and/or chondroitin sulfate (CS) is clinically valuable for the treatment of compromised articular cartilage, the current study evaluated the effects of these molecules on the tibial epiphyseal growth plate in female rats.METHOD:The animals were divided into two control groups, including vehicle treatment for 45 days (GC45) and 60 days (GC60) and six ovariectomized (OVX) groups, including vehicle treatment for 45 days (GV45), GS for 45 days (GE45GS), GS+CS for 45 days (GE45GS+CS), vehicle for 60 days (GV60), GS for 60 days (GE60GS) and GS+CS for 60 days (GE60GS+CS). At the end of treatment, the tibias were dissected, decalcified and processed for paraffin embedding. Morphological and morphometric methods were employed for analyzing the distal tibial growth plates using picrosirius red staining and the samples were processed for histochemical hyaluronan detection. Morphometric analyses were performed using the 6.0ProPlus® Image system.RESULTS:Notably, after 60 days of treatment, the number of proliferative chondrocytes increased two-fold, the percentage of remaining cartilage increased four-fold and the percentage of trabecular bone increased three-fold in comparison to the control animals.CONCLUSION:GS and CS treatment drugs led to marked cellular proliferation of the growth plate and bone formation, showing that drug targeting of the tibial epiphyseal growth plate promoted longitudinal bone growth.     

Drospirenone increases central and peripheral beta-endorphin in ovariectomized female rats

OBJECTIVE: Drospirenone is the unique progestin derived from 17-spironolactone used for contraception and hormone therapy. Few data are available concerning the effects of drospirenone on the central nervous system and neuroendocrine milieu. The opioid beta-endorphin and the neurosteroid allopregnanolone are considered markers of neuroendocrine functions, and their synthesis and activity are regulated by gonadal steroids. The aim of the present study was to evaluate the effect of a 2-week oral treatment with drospirenone, estradiol valerate, and combined therapy of drospirenone + estradiol valerate on central and peripheral beta-endorphin and allopregnanolone levels in ovariectomized female rats. DESIGN: Seven groups of Wistar ovariectomized rats received oral drospirenone (0.1, 0.5, and 1.0 mg/kg per day), estradiol valerate (0.05 mg/kg per day), or drospirenone (0.1, 0.5, and 1.0 mg/kg per day) + estradiol valerate (0.05 mg/kg per day). One group of fertile and one group of ovariectomized rats were used as controls. beta-endorphin levels were measured in frontal and parietal lobes, hippocampus, hypothalamus, anterior and neurointermediate pituitary, and plasma, and allopregnanolone content was assessed in frontal and parietal lobes, hippocampus, hypothalamus, anterior pituitary, adrenal glands, and serum. RESULTS: Ovariectomy induced a significant decrease in beta-endorphin and allopregnanolone content in all brain areas analyzed and in circulating levels, whereas it increased allopregnanolone content in the adrenal gland. Estradiol valerate replacement increased beta-endorphin and allopregnanolone levels in all brain areas analyzed and in plasma/serum. Drospirenone treatment significantly increased beta-endorphin levels in all brain areas analyzed (with the only exception being the parietal lobe), whereas it produced no effect on allopregnanolone levels. The addition of drospirenone to estradiol valerate did not modify the effects of estradiol valerate on beta-endorphin or allopregnanolone levels. Drospirenone showed an additive and synergistic effect with estradiol in the neurointermediate lobe on beta-endorphin synthesis. CONCLUSIONS: Drospirenone significantly increases central and circulating beta-endorphin levels and does not seem to interfere with allopregnanolone production.     

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) ;     

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：     

阿仑膦酸钠改善去卵巢大鼠的骨基质结构

背景：双膦酸盐可以提高骨密度、抑制骨吸收的作用已被临床所证实,但其对于骨骼基质结构的影响研究较少。 目的：实验通过观察双膦酸盐类药物——阿仑膦酸钠对骨结构及骨基质代谢的影响,探讨阿仑膦酸钠改善骨质量、提高骨强度的骨基质调控机制。 方法：实验建立去卵巢大鼠模型,用阿仑膦酸钠进行干预,同时设置模型组和假手术组进行对照。运用骨骼影像学、骨组织病理学和骨生物力学检测技术与酶联免疫吸附法观察阿仑膦酸钠对骨丢失大鼠骨密度、骨代谢、骨生物力学性能和骨结构的影响。 结果与结论：药物干预后4,8,12周,阿仑膦酸钠组骨密度均高于模型组(P < 0.05);药物干预8周后,与模型组相比,阿仑膦酸钠组骨代谢指标尿脱氧吡啶诺啉,血清Ⅰ型胶原羧基端前肽水平均降低(P < 0.05),腰椎和股骨的最大载荷、最大压强、模量以及Ⅰ型胶原不同交联形式的尿吡啶啉/脱氧吡啶啉值均增高(P < 0.05)。结果证实,阿仑膦酸钠能够对抗因雌激素缺乏导致大鼠骨量的丢失,提高生物力学性能,改善骨基质结构,同时恢复因去卵巢所导致的Ⅰ型胶原交联组分的改变。 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：     

Long-term osteopenic changes in cancellous bone structure in ovariectomized rats

Cancellous bone mass decreases following ovariectomy in rodents, providing a useful model for post-menopausal bone loss in humans. This study describes and quantifies the longer-term changes in cancellous bone structure in the ovariectomized (OVX) rat. Rats were OVX or sham-OVX at 100 days of age and bones were collected 540 days later. Lumbar vertebral bodies were prepared for microradiography and structural analyses (nodal analyses and star volume analyses) of cancellous bone. Proximal humerii were prepared for scanning electron microscopy (SEM). Microradiography confirmed the loss of cancellous bone from the central spongiosa regions of the vertebral bodies and the humerii in the OVX rats. Changes in trabecular structural elements included relative increases in the number of free to free, cortical to free, cortical to node struts and decreases in the node to node struts in the OVX animals compared with controls. There were increases in average lengths of the node to free, node to node, and free to free trabecular struts in the OVX animals. The marrow star volume was increased in the OVX animals indicating a greater trabecular separation in these animals compared with controls. Viewed by SEM, metaphyseal trabeculae in the controls consisted of rods and plates but in the OVX animals the remaining trabeculae were mostly longitudinal rods with smaller transverse connecting rods. The remaining bone in the OVX animals was found in the lateral metaphyseal areas and is consistent with maintenance of the structural capacity of the bone. These long-term changes in cancellous bone structure are likely due to the continuation of functional skeletal loading but a decrease in gonadal hormones resulting in a decreased necessity to maintain a skeletal mineral store for reproduction (e.g., pregnancy and lactation). © 1993 Wiley-Liss, Inc.     

辛伐他汀对去卵巢骨质疏松大鼠股骨生物力学的影响

目的研究辛伐他汀(Simvastatin,SIM)对去卵巢(OVX)骨质疏松大鼠股骨生物力学性能的影响。方法48只3月龄雌性SD大鼠,随机分成3组,假手术(SHAM)组、OVX组和OVX+SIM组,每组8只。适应性喂养一周后进行手术。术后8周开始给药,OVX+SIM组给予SIM 5mg.kg-1·d-1,其余两组用等量生理盐水灌服。用药后第4周每组随机处死半数大鼠,12周后处死剩余大鼠,取股骨进行三点弯曲试验,检测股骨最大载荷、弹性载荷、最大桡度、弹性桡度、弯曲刚度系数、弯曲韧度系数等生物力学性能。结果(1)用药4周,最大载荷:SHAM组较OVX组明显增加(P<0.05);弹性载荷:OVX+SIM组较OVX组明显降低(P<0.05);最大桡度:SHAM组较OVX组明显增加(P<0.05);弯曲韧度系数:OVX+SIM组较OVX组明显增加(P<0.01)。(2)用药12周,最大载荷:OVX+SIM组、SHAM组较OVX组明显增加(P<0.05,P<0.01);弹性载荷:OVX+SIM组较OVX组明显增加(P<0.05);弯曲韧度系数:OVX+SIM组、SHAM组较OVX组明显降低(P<0.05,P<0.01)。(3)用药12周较4周,OVX+SIM组最大载荷、弹性载简明显增加(P<0.01),OVX组弯曲韧度系数明显增加(P<0.01)。结论SIM能促进去势大鼠骨的再建,改变骨的空间微结构和骨组织有机成分和无机成分的比例及结合,随时间的延长能提高股骨的强度。     

Comparative effects of risedronate,atorvastatin, estrogen and SERMs on bone mass and strength in ovariectomized rats

Objective

The aim of this study was to investigate bone protective effects of risedronate, atorvastatin, raloxifene and clomiphene citrate in ovariectomized rats.

Methods

Our study was conducted on 63 rats at Experimental Research Center of Celal Bayar University. Six-month-old rats were divided into seven groups. There were five drug administered ovariectomized groups, one ovariectomized control group without drug administration and one non-ovariectomized control group without drug administration. Eight weeks postovariectomy, rats were treated with the bisphosphonate risedronate sodium, the statin atorvastatin, the estrogen 17β-estradiol and the selective estrogen receptor modulators (SERMs) raloxifene hydrochloride and clomiphene citrate by gavage daily for 8 weeks. At the end of the study, rats were killed under anesthesia. For densitometric evaluation, left femurs and tibiae were removed. Left femurs were also used to measure bone volume. Right femurs were used for three-point bending test.

Results

Compared to ovariectomized group, femur cortex volume increased significantly in non-ovariectomized group (p = 0.016). Compared to non-ovariectomized group, distal femoral metaphyseal and femur midshaft bone mineral density values were significantly lower in ovariectomized group (p = 0.047). In ovariectomy + atorvastatin group, whole femur and femur midshaft bone mineral density and three-point bending test maximal load values were significantly higher than ovariectomized group (p = 0.049, 0.05, and 0.018). When compared to the ovariectomized group, no significant difference was found with respect to femoral maximum load values in groups treated with risedronate, estrogen, raloxifene and clomiphene (p = 0.602, 0.602, 0.75, and 0.927). In ovariectomy + risedronate group, femur midshaft bone mineral density values were significantly higher than the values in ovariectomized group (p = 0.023). When compared to ovariectomized group, no significant difference was found with respect to femur midshaft bone mineral density values in groups treated with estrogen, raloxifene and clomiphene (p = 0.306, 0.808, and 0.095).

Conclusions

While risedronate sodium prevented the decrease in bone mineral density in ovariectomized rats, atorvastatin maintained mechanical characteristics of bone and also prevented the decrease in bone mineral density as risedronate sodium.     

去势大鼠骨质疏松性骨小梁的压缩断裂仿真

文题释义： 原发性骨质疏松症：是一种以骨量降低、骨微结构破坏、骨脆性增加、骨折风险性增大为特征的全身性骨骼系统疾病,其多发于老年人,尤以绝经后妇女多见。 断裂：材料或构件力学性能的基本表征。根据断裂前发生的塑性变形的大小,可把材料的断裂分为脆性断裂和延性断裂两大类。随材料和条件的不同,循环载荷作用下的疲劳断裂、高温下的蠕变断裂以及环境作用下的应力腐蚀断裂,均可表现为脆性断裂和延性断裂。 背景：目前已有相关有限元模型仿真模拟了股骨骨折,并探讨了载荷速率、载荷角度及松质骨在髋部骨折中的影响,但骨小梁的断裂仿真仍缺乏相关研究。 目的：仿真模拟去势大鼠骨质疏松性骨小梁压缩断裂的生物力学过程。 方法：取去势大鼠右侧股骨于Micro-CT扫描股骨远端,获得大鼠股骨感兴趣区域骨微结构参数及三维模型,在Geomagic Studio几何优化后在Hypermesh 14.0前处理,包括体网格划分、设置材料属性参数、边界条件,设置载荷1 200 N,作用时间2 ms,在LS-DYNA软件中进行运算。 结果与结论：①感兴趣区域骨小梁显示空间分布不均;②骨小梁体积小、数量少的部位最先开始出现变形断裂,板状及较大体积的骨小梁最后发生断裂塌陷;③Von-mises应力变化趋势与骨小梁断裂塌陷趋势大致相同;④感兴趣区域骨小梁断裂塌陷过程包括了垂直塌陷和水平扭转,其中水平扭转程度及速率低于垂直塌陷,使得横断面扭转成角大小及成角速率小于冠状面成角;⑤破坏单元的剪切应力增幅及峰值较Von-mises应力小;⑥提示骨小梁断裂塌陷是个复杂的过程,包含了不同平面的变形、成角。 ORCID: 0000-0002-5792-3012(吴宇航) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Oral administration of beta-cryptoxanthin prevents bone loss in ovariectomized rats

The effect of beta-cryptoxanthin, a kind of carotenoid, on ovariectomy-induced bone loss was investigated. beta-cryptoxanthin was isolated from Satsuma mandarin (Citrus unshu. MARC). beta-cryptoxanthin (5 or 10 microg/100 g body weight) was orally administered once daily for 3 months to ovariectomized (OVX) rats. OVX induced a significant increase in body weight and a significant decrease in serum calcium and inorganic phosphorus concentrations as compared with those of sham-operated (control) rats. These alterations induced by OVX were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). The analysis using a peripheral quantitative computed tomography (pQCT) showed that OVX induced a significant decrease in mineral content and mineral density in the femoral-diaphyseal and -metaphyseal tissues and polar strength strain index in the metaphyseal tissues. These decreases were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). Moreover, OVX induced a significant decrease in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and -metaphyseal tissues and deoxyribonucleic acid (DNA) content in the metaphyseal tissues. These decreases were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). This study demonstrates that beta-cryptoxanthin has a preventive effect on OVX-induced bone loss in vivo.     

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。     

Vibrational bone characteristics versus bone density for the assessment of osteoporosis in ovariectomized rats

Our previous research findings suggested this integrated study in order to monitor changes of bone properties and assess bone integrity using vibrational characteristics in osteoporosis. The method is based on measurement of the bone dynamic characteristic modal damping factor (MDF). The experimental animal model is ovariectomized rat followed by alendronate treatment. According to the experimental design, adult female Wistar rats are ovariectomized and 60 days later, with confirmed osteoporosis, the population is divided into two groups. One is administered alendronate and the second is given no treatment. Furthermore, established techniques such as pQCT and histomorphometry are applied at all time points, in order to compare and correlate to MDF. The results indicate induction of osteoporosis due to ovariectomy and render MDF capable of monitoring changes in bone material properties and architecture, with high sensitivity and repeatability.     

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.     

Glucoprivation increases estrogen receptor alpha immunoreactivity in the brain catecholaminergic neurons in ovariectomized rats

Estrogen-dependent enhancement of glucoprivic-induced luteinizing hormone (LH) suppression is hypothesized to be due to increased estrogen receptor alpha (ERalpha)-immunoreactive (ir) cells in specific brain nuclei in a manner similar to fasting. ERalpha expression in various brain areas was determined in ovariectomized rats after systemic 2-deoxy-D-glucose (2DG)-induced glucoprivation. Expression of ERalpha in catecholaminergic neurons in the lower brainstem was also examined. ERalpha-ir cells increased in hypothalamic paraventricular and periventricular nuclei, and A1 and A2 regions of the brainstem 1 h after 2DG injection. The percentage of ERalpha in the tyrosine hydroxylase (TH)- and dopamine-beta-hydroxylase (DBH)-ir neurons was higher in A1 and A2 regions of 2DG-treated rats, but the number of TH- and DBH-ir cells did not change. Thus, 2DG induces ERalpha expression in specific brain nuclei and expression of ERalpha in catecholaminergic neurons of the brainstem indicates a role for estrogen in activating those neurons projecting to the hypothalamic paraventricular nucleus to suppress LH secretion during glucoprivation.     

Resistance training attenuates fat mass regain after weight loss in ovariectomized rats

Objective

The aim of the present study was to investigate the effects of maintaining only one of the two components of a food restriction (FR) + resistance training (RT) regimen on the regain of body weight and fat mass (liver and adipocytes) in ovariectomized (Ovx) rats.

Methods

Five week Ovx rats were submitted to a weight loss program consisting of a 26% FR combined with RT (OvxFR + RT) for 8 weeks. RT consisted of climbing a 1.5 m vertical grid with a load attached to the tail, 20–40 times with progressively increasing loads 4 times/week. Following this weight loss intervention, OvxFR + RT rats were sub-divided into 3 groups for an additional 5 weeks: 2 groups went back to a normal ad libitum feeding with or without RT and the other group kept only FR.

Results

Combined FR + RT program in Ovx rats led to lower body mass gain, liver triacylglycerol (TAG) levels, and fat mass gain compared to sedentary normally fed Ovx rats (P < 0.01). Stopping both FR and RT over a 5 week period resulted in the regain of body weight, intra-abdominal fat pad weight and liver TAG (P < 0.01). When only FR was maintained, the regain of body and fat pad weight as well as liver and plasma TAG concentrations was completely prevented. However, when only RT was maintained, regain in the aforementioned parameters was attenuated but not prevented (P < 0.05).

Conclusion

It is concluded that following a FR + RT weight loss program, continuation of only RT constitutes an asset to attenuate body weight and fat mass regain in Ovx rats; although the impact is less than the maintaining FR alone. These results suggest that, in post-menopausal women, RT is a positive strategy to reduce body weight and fat mass relapse.     

Influence of ferutinin on bone metabolism in ovariectomized rats. II: Role in recovering osteoporosis

The aim of the present investigation, which represents an extension of a previous study, was to investigate the effect of ferutinin in recovering severe osteoporosis due to estrogen deficiency after rat ovariectomy and to compare phytoestrogen effects with those of estrogens commonly used in hormone replacement therapy (HRT) by women with postmenopausal osteoporosis. The animal model used was the Sprague–Dawley ovariectomized rat. Ferutinin was orally administered (2 mg kg⁻¹ per day) for 30 or 60 days starting from 2 months after ovariectomy (i.e. when osteoporosis was clearly evident) and its effects were compared with those of estradiol benzoate (1.5 μg per rat twice a week, subcutaneously injected) vs. vehicle-treated ovariectomized (OVX) and sham-operated (SHAM) rats. Histomorphometric analyses were performed on trabecular bone of lumbar vertebrae (4th and 5th) and distal femoral epiphysis, as well as on cortical bone of femoral diaphysis. Bone histomorphometric analyses showed that ferutinin seems to display the same effects on bone mass recorded with estradiol benzoate, thus suggesting that it could enhance the recovery of bone loss due to severe estrogen deficiency in OVX rats. On this basis, the authors propose listing ferutinin among the substances representing a potential alternative for the treatment of postmenopausal osteoporosis, which occurs as a result of estrogen deficiency.     

复合振动对卵巢切除大鼠骨质量的作用

背景：目前所使用的全身振动防治骨质疏松所需振动强度较大,人体不适感较强。作者设计了复合振动,前期实验发现复合振动可在更低强度下有效预防卵巢切除大鼠的骨密度下降。 目的：课题创新性提出低强度复合振动可维持生长期卵巢切除SD大鼠骨质量的理论假设,并期望实验结果加以验证。 方法：SPF级4月龄雌性未育SD大鼠32只,随机分为正常对照组、卵巢切除组以及振动1、振动2组,每组大鼠均为8只。振动1组接振45~55 Hz,0.05~0.1 g;振动2组接振45~55 Hz,0.12~0.21 g。振动20 min/次,1次/d,5次/周,休息间隔不大于2 d。实验时间13周。观察振动干预前后大鼠活体骨密度,体外标本骨微结构以及生物力学性能。 结果与结论：卵巢切除组腰椎骨密度下降(P < 0.05),而正常对照组与两振动组有显著性增加,股骨骨密度均增加,组间差异无显著性意义;卵巢切除各组骨微结构参数均明显下降,但振动2组骨小梁数量、骨小梁厚度、骨小梁间距、骨体积分数相对于卵巢切除组有显著改善;腰椎骨强度值两振动组较卵巢切除组显著增加(P=0.025、0.006),与正常对照组比较差异无显著性意义。实验结果证明,特定的复合振动舒适感较好的低强度下可以有效预防卵巢切除SD大鼠骨密度下降,减轻骨微结构破坏程度,维持骨强度,具有改善卵巢切除大鼠骨质量的作用和潜在的预防骨质疏松作用。     

去势大鼠骨形态计量学、生物性能变化

目的 通过观察大鼠血清学、骨形态计量学测定、骨生物性能等方法研究去卵巢大鼠骨变化.方法 采用7-12月龄SD雌性大鼠30只,随机分为对照组、模型组和尼尔雌醇组.模型组和尼尔雌醇组大鼠切除双侧卵巢进行造模.尼尔雌醇组大鼠造模后45天开始灌服尼尔雌醇,连续90天;对照组和模型组大鼠手术后第45天开始灌服去离子水,连续90天.所有大鼠给药第80、87天时两次ip四环素20mg/kg进行骨荧光标记.实验结束时,取出大鼠股骨及第四腰椎骨进行股骨形态计量学测定、股骨骨密度测量、股骨三点弯曲实验及椎骨压缩实验,同时测定血清碱性磷酸酶(ALP)、抗酒石酸酸性磷酸酶(StrACP)水平.结果 大鼠去双侧卵巢后,股骨骨密度、骨最大载荷、最大应力、弹性模量、刚度水平和骨小梁体积显著性提高;椎体压缩性能、股骨形态计量学、股骨弯曲性能有明显改变;而雌激素对以上变化有不同程度改善作用.结论 骨组织形态、骨生物性能是评价骨质疏松模型或药物疗效的重要指标;发生骨质疏松时,骨组织形态学变化先于骨生物性能变化.     

去势大鼠5种骨转换生化指标的动态变化

目的： 对去势大鼠骨质疏松动物模型形成过程中5种骨转换指标的变化及其相关性进行研究。方法: 将3月龄SD雌性大鼠分为3组：切除卵巢组(OVX)，假手术组(sham)和对照组(control)，术前和术后分别于1、1.5、2、2.5、3和4月检测血清骨钙素(OC)、碱性磷酸酶(ALP)、 骨碱性磷酸酶(BALP)、抗酒石酸酸性磷酸酶(TRAP)和羟脯氨酸(HYP)水平，并作大鼠胫骨病理切片检查。结果: OVX组血清OC、ALP、BALP、TRAP和HYP水平均明显高于sham组，其变化顺序依次为：TRAP/HYP→OC→ALP/BALP；5种指标之间呈显著正相关；术后3月OVX组大鼠胫骨小梁结构有病理改变。结论: 去势大鼠属于高转换型骨质疏松；在模型形成过程中，骨吸收指标的变化早于骨形成指标的改变；骨转换指标是反映绝经后早期骨量丢失的灵敏指标。