中药联合胰岛素预防糖尿病去卵巢大鼠骨质疏松症

目的研究中药对糖尿病并发去卵巢大鼠骨质疏松症的影响。方法80只雌性Wistar大鼠随机平均分为4组：假手术组（A组）、糖尿病假手术组（B组）、糖尿病去卵巢组（C组）和糖尿病去卵巢中药干预组（D组）,造模成功12周后应用双能X线骨密度仪测定骨密度。结果L5、L4椎体骨密度在各组的数值变化关系：A组〉D组〉B组〉C组。其中,L5椎体骨密度D组与A、B、C组相比差异均具有统计学意义（P〈0．01或P〈0．05）;L5椎体骨密度D组与A、C组相比差异均具有统计学意义（P〈O．01）,D组与B组相比差异无统计学意义（P〉0．05）。股骨的骨密度D组与A组相比差异无统计学意义（P〉0．05）,与C组相比差异具有统计学意义（P〈0．01）。结论补肾中药结合胰岛素治疗可预防糖尿病去卵巢大鼠骨质疏松模型。     

去卵巢骨质疏松模型大鼠L4脊椎骨的应力松弛与蠕变☆

背景：去卵巢大鼠脊椎骨会发生哪些应力松弛与蠕变及时间的变化规律？目的：观察去卵巢骨质疏松对雌性大鼠承重骨黏弹性特性的影响。方法：Wistar雌性大鼠44只随机等分为对去卵巢骨质疏松动物模型组和对照组。模型组大鼠于0周摘除卵巢,14周后对大鼠L4椎骨进行应变增加速度为1%/s的应力松弛实验和应力增加速度为0.01 MPa/s的蠕变实验,在7 200 s采集100个数据。结果与结论：大鼠L4椎骨对照组7 200 s应力松弛量和蠕变量大于模型组(P < 0.05);同时大鼠L4椎骨应力松弛曲线是以对数关系变化的,蠕变曲线是以指数关系变化的。提示去卵巢骨质疏松大鼠椎骨黏弹性力学特性发生了改变。     

苯甲酸雌二醇对去卵巢大鼠慢性前脑缺血脑保护作用的研究

目的观察苯甲酸雌二醇对去卵巢大鼠慢性前脑缺血脑组织病理形态、学习记忆以及死亡率的影响,探讨雌激素对慢性缺血性脑损害的保护作用。方法50只健康雌性Wistar大鼠,随机分为4组。A组:正常对照组,n=5;B组:假去卵巢缺血组,n=15;C组:去卵巢缺血组n=15;D组:去卵巢缺血苯甲酸雌二醇治疗组。各组按要求制备模型,应用Morris水迷宫筛选并检测记忆功能,坚劳蓝 焦油紫染色、CD31免疫组化染色观察额叶皮质和海马CA1区神经元毛细血管变化。结果A组大鼠额叶皮质和海马CA1区神经元、毛细血管形态正常,学习记忆功能良好,B、C、D组与A组相比上述指标改变明显,差异具有显著性(P<0.05),而且C组改变明显重于B、D组(P<0.05);C组额叶皮质神经元、毛细血管和海马CA1区神经元数量减少,与A、B、D组相比差异具有显著性(P<0.05),B、D组相比上述改变无差异(P>0.05);缺血后各组大鼠急性期死亡率比较,差异无显著性(P>0.05)。结论雌激素对去卵巢慢性前脑缺血大鼠额叶皮质及海马CA1区病理变化以及学习记忆功能均产生了有益的影响,但未能降低急性期大鼠的死亡率。     

长期口服雌激素或复方雌激素对去卵巢大鼠海马结构内β-淀粉样蛋白沉积的影响

目的观察长期口服雌激素或复方雌激素对去卵巢大鼠大脑海马结构内β-淀粉样蛋白(Aβ)沉积的影响。方法7月龄SD大鼠随机分成5组:正常对照组、假手术组、去卵巢组、17β-雌二醇预防干预组(雌二醇干预组)和复方尼尔雌醇预防干预组(尼尔雌醇干预组)。去卵巢组、雌二醇干预组及尼尔雌醇干预组手术切除卵巢,并分别对雌二醇干预组及尼尔雌醇干预组饲喂相应的药物35周,处死各组大鼠,用免疫组化法、细胞计数及图像分析观察各组大鼠海马结构内Aβ沉积的变化。结果去卵巢组海马结构内各亚区Aβ阳性神经元数量和平均光密度明显高于其他4组(均P<0·05)。结论长期雌激素缺乏导致大鼠海马结构内Aβ沉积增加,减少Aβ的沉积可能是雌激素神经保护的重要机制之一,雌激素与复方雌激素效果相同。     

去卵巢、去松果体对大鼠杏仁核细胞凋亡的影响

阿尔茨海默病(Alzheimer’s disease，AD)临床主要表现为记忆力减退，其中受情绪影响的长时记忆减退主要与杏仁核的神经元减少有关。AD的病因至今不清，近来研究结果显示，体内雌激素(estrogen，E)、褪黑素(melatonin，MT)缺乏与AD发病有关，而细胞凋亡可能参与了发病过程心。     

去卵巢大鼠胆碱能神经系统改变及雌激素保护作用机制的研究

目的观察去卵巢大鼠胆碱能神经系统的改变及雌激素对其影响。方法利用免疫组织化学染色结合图像分析方法观察去卵巢大鼠海马CA1区胆碱乙酰转移酶(ChAT)的变化;利用RT—PCR方法检测去卵巢大鼠基底前脑神经生长因子(NGF)mRNA表达的变化。结果去卵巢大鼠海马CA1区ChAT的积分光密度(OD)值降低,基底前脑NGFmRNA平均表达水平明显降低,补充雌激素后以上各项指标均明显提高。结论(1)去卵巢大鼠海马CA1区胆碱能神经元ChAT活性下降,基底前脑胆碱能神经元NGFmRNA表达水平降低。(2)雌激素能够上调去卵巢大鼠NGFmRNA表达．而NGF能够增强ChAT的活性。促进乙酰胆碱(Ach)的合成和释放,改善学习记忆能力。     

骨质疏松大鼠MSCs生物学特性的研究

背景：随着近年来对骨质疏松机制研究的深入,研究者逐渐把研究重点放在了成骨细胞的来源骨髓间充质干细胞上。目的：对骨质疏松大鼠骨髓间充质干细胞进行分离和体外培养,观察骨质疏松模型大鼠骨髓间充质干细胞的生物学特性,分析骨质疏松的细胞病理学机制,以期为骨质疏松的防治提供一个有意义的药物靶标。方法：选用10月龄SD雌性大鼠去卵巢增龄3个月来复制骨质疏松模型,设假手术对照组。运用密度梯度离心法对两组大鼠骨髓间充质干细胞进行分离和体外培养,运用扫描电镜对培养的骨髓间充质干细胞进行形态学观察,并行生长曲线及贴壁率检测。结果与结论：骨质疏松大鼠的骨髓间充质干细胞增殖能力明显下降,与对照大鼠相比存在许多结构特征的差异。体外实验结果表明,骨质疏松大鼠骨髓间充质干细胞的体外增殖能力下降可能是骨质疏松的细胞病理学机制。关键词：间充质干细胞;骨质疏松;去卵巢素;大鼠;贴壁率     

去卵巢大鼠下丘脑-垂体-卵巢轴的功能代偿机制研究

目的：在细胞和分子水平上，探讨机体因各种原因导致卵巢功能低下时，下丘脑-垂体-卵巢轴(HPOA)功能的自然代偿机制。方法：观察大鼠切除卵巢后1～6个月，下丘脑促性腺激素释放激素(Gonadotmpin releasing hormone，GnRH)及其mRNA表达的改变以及阴道脱落细胞形态和外周血雌二醇(E2)水平的变化。结果：去卵巢后5～6个月时，大鼠阴道涂片出现成熟脱落细胞；4个月时血E2水平明显升高，6个月时几乎稳定在正常水平的一半以上；随去卵巢时间延长，大鼠下丘脑GnRH神经元数目较去卵巢1个月时逐渐增多，至6个月时，升高有显著差异，但仍低于正常组数目；去卵巢1个月大鼠下丘脑组织GnRHmRNA表达明显减少，去卵巢后5个月明显升高，与正常组相比没有显著差异；GnRH棘型神经元的比例在去卵巢4个月时即升高到正常水平。结论：大鼠卵巢功能低下时，机体体内可能存在一种自然代偿作用，使异常的HPOA功能趋于正常化。     

雌激素对去卵巢大鼠学习记忆功能及海马神经元的保护作用

目的 研究雌激素对去卵巢(OVX)大鼠学习记忆功能及海马神经元的保护作用.方法 切除雌性SD大鼠双侧卵巢制作OVX大鼠模型,给予雌二醇(E2)200 μg/kg(OVX+E2组)皮下注射,每周2次,共5周.用Morris水迷宫试验检测大鼠学习记忆功能,HE染色及Bielschowski染色法观察海马神经元形态,免疫组化法观察海马tau蛋白磷酸化变化;并与OVX组和正常对照组比较.结果 与OVX组大鼠相比,OVX+E2组大鼠Morris水迷宫测试成绩明显改善(均P<0.05);海马CA1区神经元及纤维形态较规则,tau蛋白磷酸化阳性细胞数明显减少(均P<0.05).结论 OVX雌性大鼠应用雌激素可改善学习记忆功能障碍、保护海马神经元及降低tau蛋白磷酸化水平.     

补骨脂水煎剂对去卵巢骨质疏松大鼠骨代谢的影响

背景：采用雌激素替代疗法可以缓解绝经后妇女骨质疏松症状,但长期应用会出现明显的毒副作用;具有雌激素活性的补骨脂在治疗骨质疏松症方面有明显效果,且可避免使用雌激素带来的副作用。 目的：观察补骨脂水煎剂对去卵巢骨质疏松大鼠骨代谢和血清细胞因子的影响。 设计、时间及地点：随机对照,动物体内实验,于2008-04/07在山西医科大学生理学实验动物中心实验室完成。 材料：100 mL含100 g生药的100%浓度的补骨脂水煎剂由山西省第二人民医院中药房鉴定制备。肿瘤坏死因子α试剂盒为北京晶美生物工程有限公司产品,骨钙素、1,25-二羟基维生素D3、雌二醇试剂盒为上海卓康生物科技有限公司产品。QDR型4500A双能X射线骨密度仪为美国HOLOGIC公司产品。 方法：选用健康雌性鼠龄4个月的Wistar 大鼠22 只,随机将22只大鼠分为假手术组7只、模型组7只,补骨脂组8只,后2组采用切除双侧卵巢的方法制备骨质疏松模型,假手术组不切除卵巢。补骨脂组在造模后灌胃补骨脂水煎剂每天早晚各 3 mL,其余组灌胃等量生理盐水,共12周。 主要观察指标：给药结束后,分别按试剂盒操作说明测定血清雌二醇,骨钙素,1,25-二羟基维生素D3,肿瘤坏死因子α水平。利用QDR 4500A型DEXA骨密度仪测量大鼠股骨密度。 结果：与假手术组比较,模型组大鼠血清雌二醇、1,25-二羟基维生素D3水平和骨密度显著降低（P < 0.01）,血清肿瘤坏死因子α水平、骨钙素水平升高（P < 0.05）。与模型组比较,补骨脂组大鼠血清雌二醇仍处于较低水平,骨密度、血清 1,25-二羟基维生素D3、骨钙素水平明显升高（P < 0.05~0.01）,血清肿瘤坏死因子α水平显著降低（P < 0.01）。 结论：补骨脂水煎剂可改善去卵巢骨质疏松大鼠骨代谢指标和血清细胞因子水平。     

雌激素与辛伐他汀序贯法干预对去势大鼠骨质疏松的治疗作用

背景：Frost根据骨重建的概念创建了骨重建干预理论——序贯疗法,即在骨吸收抑制剂之后可给予刺激骨形成的药物。 目的：基于骨重建干预理论,序贯应用雌激素与辛伐他汀干预骨重建吸收期和形成期,观察其对去势大鼠骨质疏松的治疗作用。 方法：3月龄雄性SD大鼠40只,以随机数字表法分为去势组与正常对照组。去势组切除双侧卵巢,正常对照组只进行下腹部皮肤单纯切开术。大鼠去势后1个月,将去势组随机分为3组：序贯组、雌激素组、去势对照组,并开始药物干预：序贯组,皮下注射苯甲酸雌二醇0.1 mg/kg,3 d给药1次,2周后,灌胃给予辛伐他汀5 mg/(kg•d)2周,停药5周,再应用辛伐他汀5 mg/(kg•d)灌胃2周;雌激素组,皮下注射苯甲酸雌二醇0.1 mg/kg,每3 d给药1次,连续用药11周;去势对照组,单纯的饲料喂养,无药物干预。11周后,双能X射线骨密度仪测定股骨骨密度,放射免疫法检测血清白细胞介素6、骨钙素水平。 结果与结论：各治疗组大鼠股骨骨密度、骨钙素水平高于去势对照组(P < 0.05),并且序贯组明显高于雌激素组(P < 0.05)。各治疗组白细胞介素6水平低于去势对照组(P < 0.05),并且序贯组低于雌激素组(P < 0.05)。说明雌激素和辛伐他汀序贯疗法可以通过抑制骨吸收,促进骨形成有效地治疗骨质疏松。     

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。     

海藻酸多糖衍生物治疗大鼠骨质疏松

背景：作者既往研究发现海藻酸多糖衍生物有促进骨细胞生长的作用。目的：探索海藻酸多糖衍生物治疗骨质疏松的效果。方法：60只Wistar雌性大鼠随机分成对照组,治疗组和模型组,每组20只。治疗组和模型组大鼠用维甲酸诱导产生骨质疏松模型。治疗组大鼠每只每公斤每天10 mg多糖衍生物灌胃,模型组每只每公斤每天10 mg葡萄糖灌胃,持续2周。观察大鼠股骨病理形态学和骨组织形态计量学变化。结果与结论：与对照组相比,模型组大鼠股骨骨小梁面积、平均骨小梁厚度、骨小梁密度显著降低,而髓腔质间隔宽度则明显增加;经过海藻多糖衍生物治疗后,治疗组大鼠股骨平均骨小梁密度,平均骨小梁厚度和骨小梁面积较模型组均显著上升,同时髓腔质间隔宽度明显下降;说明海藻酸性多糖能有效促进骨细胞生长,可治疗和预防骨质疏松。     

补肾健脾方干预去势大鼠骨骼肌caspase-3和caspase-8的表达

背景：骨骼肌与骨质疏松症关系密切,导致其衰退的主要原因是细胞的凋亡,这种凋亡可能是Caspase家族蛋白所介导的。 目的：探讨补肾健脾方对去势大鼠骨骼肌caspase-3和 caspase-8调控作用。 方法：SD大鼠48只等随机分为对照组、模型组、中药组、西药组,后3组大鼠摘除双侧卵巢建立骨质疏松模型,对照组仅切除周围少量脂肪组织。造模2周后,中药组给予补肾健脾方(2.979 g/kg)灌胃,西药组给予戊酸雌二醇片(0.104 mg/kg)灌胃,模型组和对照组给予蒸馏水灌胃,1次/d。 结果与结论：①干预12周后,双能X线骨密度仪测量发现,相比于对照组,模型组大鼠左侧股骨的骨密度值和骨矿含量均明显降低(P < 0.01);而中药组和西药组的骨密度值均高于模型组(P < 0.05),且2组骨密度值和骨矿含量接近(P > 0.05)。②酶标免疫分析显示,与对照组相比,模型组骨骼肌中Caspase-3和 Caspase-8表达水平明显上升(P < 0.05)。中药能显著降低大鼠骨骼肌中Caspase-3的表达水平(P < 0.05),而西药能显著减低Caspase-8表达水平(P < 0.05)。③说明补肾健脾方对卵巢切除所致的骨质疏松症有明显的治疗作用,能明显提高骨密度,而且能显著减低Caspase-3的水平,但不能显著减低Caspase-8水平,显示补肾健脾方不是通过死亡受体途径去抑制细胞凋亡的。     

The effects of stimulation and lesion of raphe nuclei on luteinizing hormone release in estrogen-progesterone-treated ovariectomized rats

A study was made of the effects of electrochemically stimulating (ECS) and destroying the midbrain dorsal and median raphe nuclei on the estrogen-progesterone- (EP) induced surge of pituitary LH release in ovariectomized rats. ECS and lesions were produced simultaneously with anodal direct current through a chronically implanted stimulation-lesion electrode. Blood for LH assay was collected through a chronic intra-atrial cannula positioned on the day of first treatment with progesterone. ECS of the raphe nuclei exerted a strong inhibition of the LH surge when compared with sham stimulation. On the second EP treatment the onset of the LH surge was advanced both in sham-stimulated animals and in rats with raphe lesions resulting from the anodal direct current of the initial ECS. It was suggested that this apparent facilitation of the LH surge on the second EP treatment was the result of reduced stress or an altered hormonal milieu and not a consequence of destroying the raphe nuclei. The results confirm in a chronic preparation that stimulation of raphe nuclei depresses the EP-induced LH surge and that subsequently in the absence of the raphe nuclei the LH response to EP treatment is apparently normal.     

Dynamic changes of beta-amyloid protein deposition in hippocampus of female ovariectomized rats

BACKGROUND： To evaluate and summarize the effects of cerebral perfusion and vascular reserve on the treatment of SICAS. Recently, research on β-amyloid protein has focused on the regulatory effects of estrogen or phytoestrogen on its deposition. However, there have been only a few reports on dynamic changes of β -amyloid protein deposition in hippocampus of ovariectomized rats. OBJECTIVE： To measure β -amyloid protein deposition in the hippocampal formation of ovariectomized rats by using immunohistochemistry; to observe time-dependent dynamic changes. DESIGN： Randomized controlled animal study. SETTING： Third Xiangya Hospital of Central South University. MATERIALS： The experiment was carried out in the Central Laboratory of the Third Xiangya Hospital of Central South University from November 2005 to December 2006. Fifty healthy female Sprague Dawley （SD） rats, weighing （293 ± 10） g, were provided by the Animal Laboratory of Xiangya Medical College, Central South University. All rats had neither a childbearing history nor hepatic or renal disease, or skeletal deformity. β-amyloid protein immunohistochemical kit was provided by Wuhan Boster Company. The experiment was in accordance with animal ethics standards. METHODS： All rats were randomly divided into five groups, including normal control group （n = 10）, sham operation group （n = 10）, and ovariectomized group （n = 30）. After anesthesia in the ovariectomized group, the bilateral ovaries were separated and resected. The same volume of fat was resected in the sham operation group. Rats from the normal control group, however, did not receive any surgical treatments. Rats in the normal control group and sham operation group were sacrificed by anesthesia 7 weeks after surgery. Every ten rats from the ovariectomized group was respectively sacrificed at 7, 15, and 30 weeks after surgery. lmmunohistochemistry was used to detect β-amyloid protein deposition in hippocampal sections. Cell counting and gray value measurements served to     

Plasma luteinizing hormone in ovariectomized rats following pharmacologic manipulation of endogenous brain serotonin

Ovariectomized rats were treated with pharmacologic agents to manipulate endogenous brain serotonin (5-HT). Neither the magnitude nor the timing of luteinizing hormone (LH) pulses in plasma were affected by drug-induced decreases in 5-HT. Acute increases in extraneuronal 5-HT resulting from fluoxetine administration to inhibit 5-HT uptake into neurons, decreased the magnitude of LH pulses, but did not affect the interval between successive LH pulses.     

Effects of genistein and 17 beta-estradiol on hippocampal synaptophysin expression in ovariectomized rats

BACKGROUND:Phytoestrogen,derived from plants,is an estrogen-like element,and is effective and safe for estrogen replacement.OBJECTIVE:To compare the interventional effects of genistein and 17 β-estradiol on learning and memory and synaptophysin(SYN)expression in the hippocampus of ovariectomized rats.DESIGN:Randomized controlled animal study.SETTING:Department of Neurology,the Third Affiliated Hospital,Xiangya Medical College,Central South University. MATERIALS:130 healthy female Sprague Dawley(SD)rats,6 months old and weighing(293.1±10.2)g,were provided by the Second Xiangya Hospital of Central South University.This animal experiment received confirmed consent from the local ethics committee.All rats were randomly divided into 5 groups,including baseline group(n＝10),sham operation group(n＝30),ovariectomlzed group(n＝30),genistein group(n＝ 30),and 17 β-estradiol group(n＝30).Rats in the latter four groups were observed for 3 weeks(n＝10)and for 15 weeks(n＝20)after model establishment.METHODS:This study was performed at the Department of Endocrinology,the Second Affiliated Hospital,Xiangya Medical College,Central South University from August 2005 to January 2006.Animals were not submitted to any treatment in the baseline group,but anesthetized and sacrificed at the 7 months of age.After anesthesia in the ovariectomized,genistein,and 17 β-estradiol groups,both ovaries were separated and resected to establish an ovariectomized model.The same volume of fat was resected in the sham operation group.After surgery,rats were intraperitoneally injected with 5 mg/kg genistein in the genistein group,10 μ g/kg 17 β-estradiol in the 17 β-estradiol group,and 0.1 mL/100 g dimethyl sulfoxide (DMSO)/polyethylene glycol(PEG)-200 stock solution in the sham peration and ovariectomized groups once a day until one day before sacrifice.MAIN OUTCOME MEASURES:①Learning and memory changes of SD rats were detected using water maze behavioral testing 3 and 15 weeks after surgery.②SYN expression in the hippocampus was measured using immunohistochemistry. RESULTS:A total of 16 out of 130 rats died due to infection,and 114 rats were included in the final analysis.①Comparison of water maze results from the five groups:by 3 and 15 weeks after surgery, escape latency was prolonged and platform-crossing times decreased in the ovariectomized group compared to the baseline,genistein,17 β-estradiol,and sham operation groups(t＝4.17--14.64,P＜0.05).However, there were no significant differences in escape latency and platform-crossing times among the sham operation,genistein,and 17 β-estradiol groups(P＜0.05).②Distribution and quantity of SYN immunoreactive products in hippocampus:SYN-immunoreactive cells stained darkly in the baseline and sham operation groups,but were lightly stained in the genistein,17 β-estradiol,and ovariectomized groups.In particular,SYN-immunoreactive cells stained lightly in the ovariectomized group 15 weeks after surgery. SYN correction gray values in hippocampal sub-regions,especially in the mossy fiber layer of the CA3 region,of the ovariectomized group was lower compared to the baseline,sham operation,17 β-estradiol,and genistein groups(t＝12.57-23.92,P＜0.05)15 weeks after surgery.However,there were no significant differences in SYN correction gray values among the baseline,sham operation,17 β-estradiol and genistein groups(P＜0.05).CONCLUSION:Genistein or 17 β-estradiol supplemental therapy antagonizes memory deterioration,due to endogenous estrogen deficiency and blocks the decrease of SYN expression in the hippocampus.The effect of genistein is similar to 17 β-estradiol.     

Effects of genistein and 17 beta-estradiol on hippocampal synaptophysin expression in ovariectomized rats***★

BACKGROUND： Phytoestrogen, derived from plants, is an estrogen-like element, and is effective and safe for estrogen replacement. OBJECTIVE： To compare the interventional effects of genistein and 17 S-estradiol on learning and memory and synaptophysin （SYN） expression in the hippocampus of ovariectomized rats.
DESIGN： Randomized controlled animal study.
SETTING： Department of Neurology, the Third Affiliated Hospital, Xiangya Medical College, Central South University.
MATERIALS： 130 healthy female Sprague Dawley （SD） rats, 6 months old and weighing （293.1 ± 10.2） g, were provided by the Second Xiangya Hospital of Central South University. This animal experiment received confirmed consent from the local ethics committee. All rats were randomly divided into 5 groups, including baseline group （n= 10）, sham operation group （n = 30）, ovariectomized group （n = 30）, genistein group （n = 30）, and 17 β -estradiol group （n = 30）. Rats in the latter four groups were observed for 3 weeks （n = 10） and for 15 weeks （n = 20） after model establishment.
METHODS： This study was performed at the Department of Endocrinology, the Second Affiliated Hospital, Xiangya Medical College, Central South University from August 2005 to January 2006. Animals were not submitted to any treatment in the baseline group, but anesthetized and sacrificed at the 7 months of age. After anesthesia in the ovariectomized, genistein, and 17 S-estradiol groups, both ovaries were separated and resected to establish an ovariectomized model. The same volume of fat was resected in the sham operation group. After surgery, rats were intraperitoneally injected with 5 mg/kg genistein in the genistein group,10μg/kg 17 β -estradiol in the 17 β-estradiol group, and 0.1 mL/100 g dimethyl sulfoxide （DMSO）/polyethylene glycol （PEG）-200 stock solution in the sham operation and ovariectomized groups once a day until one day before sacrifice.
MAIN OUTCOME MEASURES：① Learning and memory changes of SD r