运动对去卵巢大鼠骨大小和骨量的影响

用测定骨大小和骨量的方法,观察运动对去卵巢大鼠骨大小和骨量的影响。将健康4月龄雌性SD大鼠32只随机分成4组:正常对照组、假去卵巢组、去卵巢组、去卵巢+运动组。去卵巢+运动组大鼠于去卵巢术后第7 d开始运动训练,每周5 d,每天连续匀速跑45 min,16 m/min,跑道倾角0°,持续10周。结果表明,去卵巢大鼠骨直径、骨体积、骨湿重、骨湿重/体重、骨干重、骨干重/体重、骨干重/骨体积等指标均低于假去卵巢组。去卵巢大鼠运动训练后,骨直径、骨体积、骨湿重、骨湿重/体重、骨干重、骨干重/体重、骨干重/骨体积等指标均较去卵巢组增加,并且基本上恢复至对照组水平。提示运动有利于改善去卵巢大鼠的骨大小和骨量。     

补肾中药与阿法骨化醇联合应用对卵巢摘除大鼠原发性骨质疏松的防治作用

 目的 研究补肾中药与阿法骨化醇联合应用对卵巢去势（ovariectomy,OVX）大鼠原发性骨质疏松的防治作用。方法 手术摘除6月龄雌性大鼠双侧卵巢,随机分成4组：OVX组（ovariectomy,OVX）、OVX给予补肾中药组（OVX administrated with Bushen Chinese drugs,OVX+TCM）、OVX给予补肾中药和阿法骨化醇组（OVX administrated with Bushen Chinese drugs and alfacalciferol,OVX+TCM+VD）和OVX给予尼尔雌醇组（OVX administrated with nilestriol,OVX+CEE₃）,另设假手术对照组（SHAM）。术后35 d起给予药物至13周后处死取血、子宫、腰椎、股骨等标本,并测定比较各组以下变化：取子宫称重,计算子宫重/体重、子宫内膜厚度;放免法血测血清雌二醇（E₂）应用固体物理密度仪自动测量左股骨和腰椎L₂的骨密度;应用图像分析仪IPP计量软件分析椎体骨的组织病理形态计量;以万能材料测试仪检测右股骨与腰椎L₃的骨生物力学性能的指标;自动生化仪检测血清碱性磷酸酶（ALP）;酶免法检测尿吡啶酚（Pyd）,测尿肌酐（Cr）,计算Pyd/Cr作为骨代谢生化标志物,综合判断骨质疏松情况。结果 OVX大鼠双侧卵巢摘除完全,雌激素缺乏诱发骨质疏松指标明显;联合给药组骨量明显增加,骨结构明显改善,抗骨折性能明显提高,骨形成和骨吸收生化标志物降低;其防治骨质疏松的作用优于单用补肾中药组,并与尼尔雌醇组相仿。结论 补肾中药与阿法骨化醇联合应用对卵巢去势大鼠原发性骨质疏松有明显防治作用,避免了雌激素引起的子宫内膜增生等毒副作用。     

Estrogen deficiency and its effect on the jaw bones

Estrogen deficiency-induced postmenopausal osteoporosis has become a worldwide problem, inducing low bone mass and microarchitectural deterioration of the bone scaffolding in the vertebrae and long bones. With the prevalence of such osteoporosis on the increase, the influence of this estrogen deficiency on the jaw bones has drawn the attention of researchers and clinicians in the field of dentistry. The aim of this article is therefore to review the microstructural changes occurring after ovariectomy in the jaw bones of animal subjects. Induced estrogen deficiency clearly led to structural changes in the jaw bones and alveolar bone of animal subjects (rats and monkeys). Severe bone loss in the rat alveolar bone was principally caused by high bone resorptive activity. This activity accelerated greatly immediately after ovariectomy, and was then followed by more moderate resorptive activity, which continued over an extended period. Additionally, occlusal hypofunction further greatly accelerated the fragility of the alveolar bone structure in ovariectomized rats. Microstructural damage also seen in the alveolar bone of ovariectomized monkeys was found to be directly connected to their systemic osteoporosis. Recent investigations of the relationship in humans between systemic osteoporosis and jaw bone loss have also suggested that a connection may exist between these two. However, more research is required to confirm this connection in humans as well.     

Characterization of a new experimental model of osteoporosis in rabbits

To characterize an experimental model of osteoporosis in rabbits induced either by ovariectomy (OVX), glucocorticoids, or by a combination of both. Thirty-five rabbits were randomly allocated into five groups: bilateral OVX, daily methylprednisolone hemisuccinate (MPH) injections at a 1.5 mg/kg/day dose for 4 consecutive weeks (MPH group), or variable dose of MPH between 0.5 and 2 mg/kg/day in combination with OVX (OVX + MPH at low, medium, and high dose). Twenty-two animals were killed 6 weeks after OVX, and 13 were killed 16 weeks later. Dual-energy X-ray absorptiometry was obtained at baseline and 6 and 16 weeks after OVX. High-resolution magnetic resonance imaging (MRI) was carried out at 0 and 6 weeks after OVX. Glucose, total cholesterol, triglyceride, and oestradiol blood levels before and 16 weeks after OVX were determined. Bone mineral density (BMD) decreased significantly at lumbar spine in MPH and OVX + MPH medium-dose groups, and at global knee and subchondral bone of the knee in MPH, OVX + MPH low- and medium-dosage groups (P < 0.05). BMD variations in OVX rabbits were not significant in any of the three anatomical locations analyzed. BMD variation 16 weeks after OVX was significant at lumbar spine and global knee in the OVX + MPH medium-dose group and only at global knee in the OVX + MPH low-dose group (P < 0.05). MRI did not show bone or cartilage changes. Osteoporosis can be induced experimentally in rabbits through isolated MPH or by a combination of OVX and medium dose corticosteroid for 4 weeks. OVX alone was not sufficient to induce osteoporosis. Part of this study was presented at the 28th annual meeting of the American Society for Bone and Mineral Research, Philadelphia, PA, USA, September 15–19, 2006 [J Bone Miner Res 2006;21(suppl 1):S178]     

Effects of estrogen on basal forebrain cholinergic neurons and spatial learning

Estrogen receptors are expressed in several areas of the brain associated with cognition, including the basal forebrain cholinergic nuclei, and numerous reports have described improvements in memory in response to estrogen supplementation. The relationship between estrogen's effects on the basal cholinergic system and improvements in cognitive function, however, are obscure. We therefore undertook a study to determine the effects of estrogen on several parameters of the cholinergic system in ovariectomized rats and measured the concomitant effects on performance in the Barnes maze, a test of spatial memory. Six weeks of estradiol treatment caused an increase in choline acetyltransferase activity throughout the projection fields of the basal forebrain, including the hippocampal formation (14%), olfactory bulb (30%), and cerebral cortex (35%). Estrogen treatment also caused an increase in cell soma size of cholinergic neurons in the horizontal diagonal limb of the band of Broca and in the basal nucleus of Meynert. There was no change in the number of neurons positive for p75(NTR), nor in the level of p75(NTR) expression per neuron. Barnes maze performance was markedly improved after estradiol treatment, reinforcing the view that estrogen has beneficial cognitive effects, particularly on spatial memory. The beneficial cognitive effect was likely mediated in part by stimulation of the basal forebrain cholinergic system, especially in its neocortical projection, but was not associated with changes in the level of p75(NTR) expression.     

卵巢摘除及补充雌激素对小鼠骨折愈合中钙沉积的影响

为研究雌激素对卵巢摘除后已发生显著骨丢失的ｂａｌｂ／ｃ系小鼠股骨骨折愈合的影响，将１４４只ｂａｌｂ／ｃ小鼠随机分为假手术组（ＳＯ组）、卵巢摘除组（ＯＶＸ组）、补充低剂量雌激素组（Ｅ１组）、补充高剂量雌激素组（Ｅ２组）。小鼠于折骨后５天、１０天、１５天、２０天、３０天处死，测定骨痂中的钙盐沉积率。结果ＳＯ组、ＯＶＸ组和Ｅ１组，骨痂中的钙盐沉积率在折骨后１５天达峰值，ＯＶＸ组钙盐沉积峰值显著低于ＳＯ组     

卵巢切除后脑缺血再灌海马CA1区ET-3的表达

目的 :采用卵巢切除合并脑缺血再灌动物模型 ,通过免疫组织化学方法探讨脑缺血再灌损伤中雌激素与内皮素 3(ET 3)相互关系。方法 :将 5 4只成年雌性昆明小鼠随机分为三组 :①缺血再灌组 (IR) ,双侧颈总动脉结扎 7min ,再灌 1,3,5 ,14d (每个时间点 ,n =6 ) ;②卵巢切除 /缺血再灌组 (OVX/IR) ,在缺血再灌前1周作卵巢切除术 ,再灌 1,3,5 ,14d (每个时间点 ,n =6 ) ;③假手术对照组 (n =6 )。结果 :对照组海马CA1区可见少量散在分布的ET 3免疫阳性细胞 ,实验组各时间点ET 3免疫阳性细胞数与对照组相比均明显增多 (P<0 .0 1)。缺血再灌 1d时 ,OVX/IR组ET 3阳性细胞数明显高于IR组 (P <0 .0 1) ;5d时 ,OVX/IR组和IR组ET 3阳性细胞数达高峰。结论 :本实验提示雌激素可能在缺血再灌的早期参与对ET 3的调控 ,对神经元存活起保护作用。     

Estrogen replacement in ovariectomized rats results in physiologically significant levels of circulating progesterone, and co-administration of progesterone markedly reduces the circulating estrogen

Estrogen or progesterone replacement in ovariectomized rats is an often-used experimental system for determination of the specific effects of these hormones. In this study, two different delivery systems and two different dosage levels of estrogen, progesterone or a combination of the two have been used. Estrogen and progesterone in the circulation have been measured in response to each treatment. It is reported that estrogen treatment (237.2±49.2 pg/mL) results in physiologically significant levels of circulating progesterone (11.1±1.3 ng/mL). Also, co-administration of progesterone (23.7±2.0 ng/mL) with estrogen decreases the level of estrogen over that seen with estrogen alone (96.7±19.2 pg/mL with progesterone vs 237.2±49.2 pg/mL without progesterone). Thus, contrary to expectations, estrogen replacement therapy is not specific to estrogen and some of the antagonistic effects of progesterone are the result of a decrease in circulating estrogen, and not a specific effect on a target tissue. Whereas the mechanism of these effects has not been determined, obvious artifactitious phenomena have been excluded as being their cause. These results could have a major impact on the interpretation of past and future experiments of this kind.     

Ovariectomy shortens the life span of female mice

This study shows that lack of ovarian activity has a negative impact on the life span of female mice. The extent to which this phenomenon could be associated with the anti-inflammatory effect of estrogens was analyzed in metabolic organs and aorta, by quantitative analysis of mRNAs encoding proteins in the inflammatory cascade. We demonstrate that the TNFα, IL-1β, MCP-1, MIP-2 and IL-6 mRNA contents are increased in the liver, adipose tissue and aorta 7 months after ovariectomy (ovx) and this increased basal inflammation is maintained as the mice aged. In contrast, the extent of inflammatory gene expression is directly proportional to age in sham-operated mice. As a consequence, at 22 months, most of the inflammatory parameters examined were higher in the sham-operated group compared with the ovx group. These observations led us to propose that the decreased longevity of ovx mice may be due to an acceleration of the basal state of inflammation in metabolic organs, which is likely driven by the combination of a lack of estrogen-mediated anti-inflammatory activity and the loss of gonadal control of energy metabolism.     

跑台运动训练和停训对去卵巢大鼠腰椎骨密度和骨髓脂肪细胞数目的影响

目的:观察中等强度跑台运动训练和停训对去卵巢大鼠腰椎骨密度、骨组织形态学和骨髓脂肪细胞数目的影响。方法:将60只成年雌性SD大鼠按体重分层后随机分为假手术组、去卵巢静止组和去卵巢运动组,每组20只。去卵巢运动组每周进行4次时间45 min、速度18 m/min、跑道倾角5°的跑台训练。持续训练14周后,将各组大鼠再次按体重分层后随机分为两个亚组,即假手术16周(Sham-16)组和假手术32周(Sham-32)组、去卵巢16周(OVX-16)组和去卵巢32周(OVX-32)组以及去卵巢运动(EX)组和停训组(DEX)。Sham-16、OVX-16和EX三组大鼠在末次训练结束36-48小时内,Sham-32、OVX-32和DEX三组大鼠在停训16周时,用双能Χ线骨密度仪活体检测大鼠腰椎骨密度,常规HE染色对第2腰椎(L2)进行组织形态学观察。结果:(1)训练结束时,OVX-16组L2脂肪细胞数目显著高于Sham-16组和EX组,腰椎骨密度显著低于Sham-16组和EX组。(2)停训16周时,OVX-32组腰椎骨密度与Sham-32组比较显著下降,L2脂肪细胞数目显著增加,而DEX组与OVX-32组比较无显著性差异。结论:中等强度跑台运动对去卵巢大鼠腰椎骨密度下降的减缓效应和对骨髓脂肪细胞数目增加的抑制效应在停训16周后未能保持。