Ginkgo biloba extract EGb 761 attenuates hippocampal neuronal loss and cognitive dysfunction resulting from chronic restraint stress in ovariectomized rats

We have recently found that a combination of ovariectomy (OVX) and chronic restraint stress causes cognitive dysfunction and reduces hippocampal CA3 neurons in female rats and that estrogen replacement suppresses the OVX/stress-induced behavioral and morphological changes. In this study, we examined the effect of Ginkgo biloba extract (EGb 761), a popular herbal supplement, on the cognitive dysfunction and neuromorphological change in OVX/stress-subjected rats. Female Fisher 344 rats were randomly divided into three groups: vehicle-treated OVX, EGb 761 (50 mg/kg) -treated OVX and vehicle-treated sham-operated control groups. Two months after ovariectomy, all animals received restraint stress for 21 days (6 h/day), and were then subjected to a novel object recognition test followed by morphological examination by Nissl staining. EGb 761 was orally administered once daily until the behavioral analysis was done. Treatment with EGb 761 improved memory impairment and neuronal loss of hippocampus in the OVX/stress-subjected group in the same ways as 17beta-estradiol. On the other hand, EGb 761 did not affect the loss of bone mineral density and increase in body weight after OVX, although 17beta-estradiol attenuated them. These results have important implications for neuroprotective and cognition enhancing effects of EGb 761 in postmenopausal women and suggest that the effects are mediated by a different mechanism from estrogen.     

Tualang honey supplement improves memory performance and hippocampal morphology in stressed ovariectomized rats

Recently, our research team has reported that Tualang honey was able to improve immediate memory in postmenopausal women comparable with that of estrogen progestin therapy. Therefore the aim of the present study was to examine the effects of Tualang honey supplement on hippocampal morphology and memory performance in ovariectomized (OVX) rats exposed to social instability stress. Female Sprague-Dawley rats were divided into six groups: (i) sham-operated controls, (ii) stressed sham-operated controls, (iii) OVX rats, (iv) stressed OVX rats, (v) stressed OVX rats treated with 17β-estradiol (E2), and (vi) stressed OVX rats treated with Tualang honey. These rats were subjected to social instability stress procedure followed by novel object recognition (NOR) test. Right brain hemispheres were subjected to Nissl staining. The number and arrangement of pyramidal neurons in regions of CA1, CA2, CA3 and the dentate gyrus (DG) were recorded. Two-way ANOVA analyses showed significant interactions between stress and OVX in both STM and LTM test as well as number of Nissl-positive cells in all hippocampal regions. Both E2 and Tualang honey treatments improved both short-term and long-term memory and enhanced the neuronal proliferation of hippocampal CA2, CA3 and DG regions compared to that of untreated stressed OVX rats.     

Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.     

去卵巢和雌激素替代治疗对心肌细胞基因表达谱的影响

目的：本实验通过高通量的cDNA微阵列技术，研究去卵巢和雌激素替代治疗对心肌细胞基因表达谱的影响，寻找雌激素的靶基因。方法:用 1 400 个基因构建的cDNA微阵列检测假手术组（Ⅰ）、去卵巢组（Ⅱ，去势组）和雌激素替代治疗组（Ⅲ，替代组）3组SD雌鼠心肌组织的基因表达差异,随机选2个基因用半定量RT-PCR验证检测结果。结果:假手术组和去势组共检出心肌差异表达的基因177个，其中去卵巢导致上调的基因91个，下调的基因86个；去势组和替代组共检出心肌差异表达的基因164个，其中雌激素替代治疗后导致上调的基因113个，下调的基因54个。Ⅰ/Ⅱ和Ⅲ/Ⅱ比较，相同的差异表达基因54个，雌激素明显影响心肌膜通道和载体（18个）、细胞受体（9个）、信号转导相关基因（7个）和细胞代谢（6个）的mRNA水平。而大部分基因（45个）是在去势组表达下调，在雌激素替代组表达上调。RT-PCR实验证实了cDNA微阵列结果 。结论：长期雌激素替代治疗明显影响心肌细胞膜通道和载体、信号转导、细胞受体和细胞代谢等相关基因的表达。长期雌激素替代治疗可通过增加Na+,K+-ATPase和Na+/H+交换蛋白的基因表达，稳定心肌细胞内Na+和K+的浓度。雌激素还可抑制多巴胺受体基因的表达，预防心肌肥大、充血性心衰等心脏疾病的发生。     

The phytoestrogen alpha-zearalenol reverses endothelial dysfunction induced by oophorectomy in rats

It has been shown recently that alpha-zearalenol, a resorcyclic acid lactone, prevents bone loss in a rat model of postmenopausal bone loss. We have therefore investigated the effects of this phytoestrogen on endothelial dysfunction induced by estrogen deficiency in rats. Female mature Sprague-Dawley rats underwent a bilateral oophorectomy (OVX rats). Sham-operated animals (sham OVX rats) were used as controls. Three weeks after surgery, animals were randomized to the following treatments: alpha-zearalenol (1 mg/kg/day, i.m., for 4 weeks), 17beta-estradiol (20 microg/kg/day, i.m., for 4 weeks), or their vehicle (100 microl, i.m., of cottonseed oil). Two other groups of rats were treated with alpha-zearalenol or 17beta-estradiol plus the pure estrogen receptor antagonist ICI 182780 (2.5 mg/kg/day, i.m., for 4 weeks). Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, and plasma alpha-zearalenol were studied. We also investigated endothelial-dependent (acetylcholine, 10 nM to 10 microM) and endothelial-independent (sodium nitroprusside, 15 nM to 30 nM) relaxation of aortic rings, as well as N(G)-methyl-L-arginine (L-NMA: 10 to 100 microM)-induced vasoconstriction and calcium-dependent nitric oxide synthase (cNOS) activity in homogenates of lungs taken from both sham OVX rats and OVX rats. Untreated OVX rats had, compared with sham OVX animals, unchanged body weight, MAP, HR, and plasma cholesterol. In contrast oophorectomy reduced plasma estradiol levels (OVX, 2 +/- 0.5 pg/ml; sham OVX, 35 +/- 6 pg/ml), impaired endothelial-dependent relaxation and blunted L-NMA-induced contraction (L-NMA 100 microM: sham OVX, 2.7 +/- 0.3 g/mg tissue; OVX, 1.3 +/- 0.1 g/mg tissue). Moreover OVX rats showed a reduced calcium-dependent NO synthase (cNOS) activity. Treatment with alpha-zearalenol or with 17beta-estradiol reverted the endothelial dysfunction and increased cNOS activity in lung homogenates. These effects were abolished by the pure estrogen receptor antagonist ICI 182780. Our data suggest that alpha-zearalenol improves endothelial-dependent relaxation in OVX rats through an estrogen receptor-mediated effect.     

Influence of age and hormonal treatment on intestinal absorption of magnesium in ovariectomised rats.

This study was designed to assess the effect of age, ovariectomy and estrogen treatment on the absorption and the balance of Mg in the rat. Three groups of fifteen 6- (mature), 12- (old), and 30-month-old female rats (senescent), fed a diet containing 1.5 g of Mg/kg were used in the present study. Within each group, 10 rats were surgically ovariectomized (OVX). From day 2 until day 60 after OVX, they were s.c. injected with either solvant or 17 beta-estradiol (E: 10 mg/kg bw/48 h, n = 5). Five other rats were sham operated (SH, n = 5) and received solvent alone. Animals were pair fed 6 g/100 g bw/day and distilled water was available ad libitum. Food intake, urine and feces from each individual rat were measured 1 day per week, during the last 5 weeks. The results clearly showed that apparent Mg absorption (per cent) was not significantly altered with aging. Moreover, whatever the age, neither OVX nor E treatment had any significant effect on Mg apparent absorption.     

Immunohistochemical analysis of the effects of estrogen on intraarticular neurogenic inflammation in a rat anterior cruciate ligament transection model of osteoarthritis

Synovitis is considered as one of the factors associated with the pathogenesis of osteoarthritis (OA). There is currently a significant amount of research linking estrogen deficiencies with the development of OA in estrogen-deficient women, including postmenopausal women; however, the exact etiology remains unclear. Various neuropeptides, such as substance P (SP) and calcitonin gene-related peptide (CGRP), have been shown to contribute to synovitis in OA joints, and the influence of estrogen on the expressions of SP and CGRP in the synovium of OA joints has been noted. After ovariectomy (OVX) followed by estradiol (E2) replacement, 24 female rats were divided into three groups: OVX group, OVX + E2 replacement group (E2 group), and a sham group. All rats underwent transection of the anterior cruciate ligament at the same time. After 30 days, the histological findings of knee joints by hematoxylin-eosin staining and immunofluorescence staining of protein gene product 9.5 (pan-neuronal marker), SP, and CGRP were compared among experimental groups. The degree of synovitis in the OVX group was higher than in the E2 and sham groups. No significant differences in the density of protein gene product 9.5-immunoreactive nerve fibers were observed among the three experimental groups, but the density of SP- or CGRP-immunoreactive nerve fibers in the OVX group was significantly higher than in the E2 and sham groups. These findings suggest that estrogen partly regulates intraarticular neurogenic inflammation in OA joints by modulating the expressions of neuropeptides in the synovium.     

Enhanced activity of hippocampal BACE1 in a mouse model of postmenopausal memory deficits

Ovarian hormone decline after menopause may influence cognitive performance and increase the risk for Alzheimer's disease (AD) in women. We have recently demonstrated that a combination of ovariectomy and chronic stress (OVX/stress) causes hippocampus-associated cognitive dysfunction in mice. In this study, we examined whether OVX/stress could affect the levels of AD-related molecules in the mouse hippocampus. Female ICR mice were ovariectomized or sham-operated, and then randomly divided into a daily restraint stress (21 days, 6 h/day) or non-stress group. Although OVX or stress alone did not affect β-site amyloid precursor protein (APP)-cleaving enzyme-1 (BACE1) activity, OVX/stress increased activity in hippocampal CA1 and CA3 regions, compared with other groups. In contrast, OVX/stress did not affect γ-secretase activity, Aβ_1-40, and phosphorylated-tau levels in the hippocampus. These findings suggest that a stressful life after menopause can influence the levels of AD-related molecules and that BACE1 is the most sensitive molecule for such a situation.     

Effects of selective estrogen receptor agonists on food intake and body weight gain in rats

Ovariectomized (OVX) rats eat more and gain weight more rapidly than sham-operated (SO) rats and estradiol (E(2)) treatment attenuates food intake and body weight gain in OVX rats. Studies were designed to test the hypothesis that the alpha subtype of the estrogen receptor (ERalpha) mediates the attenuating effects of E(2) on food intake and body weight gain while the beta subtype (ERbeta) mediates opposing actions that lead to increased food intake and body weight gain. Female rats were SO or OVX and treated daily with vehicle (dimethylsulfoxide, DMSO) or E(2) (10 microg/day), or the ERalpha-selective agonist, 4,4',4'-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT, 0.5 mg/day), or the ERbeta-selective agonist, 2,3-bis(4-hyroxyphenyl)-propionitrile (DPN, 0.5 mg/day) for 14 days. Total food intake was significantly reduced by E(2) and PPT, but not DPN. Total body weight gain was significantly increased in OVX rats compared to SO rats and treatment with E(2) or PPT, but not DPN, significantly decreased total body weight gain to levels that were not significantly different from SO rats. A dose-response study of PPT indicated that at 0.25 mg/day, PPT significantly reduced total 21-day food intake and body weight gain and, at 0.13 and 0.06 mg/day, PPT significantly reduced total body weight gain compared to OVX rats without significantly reducing total food intake. A dose-response study of DPN indicated that none of the three doses of DPN significantly altered total 21-day food intake or total body weight gain. These results suggest ERalpha mediates the attenuating effects of estrogens on food intake and body weight gain while ERbeta has no effect on these variables.     

雌激素替代治疗对中年卵巢切除大鼠大脑白质、海马内髓鞘及Lingo-1蛋白的影响

目的检测经短期雌激素替代治疗(ERT)后中年卵巢切除大鼠大脑白质及海马内髓鞘相关指标及Lingo-1的表达,探讨雌激素对髓鞘作用的可能机制。方法 24只中年雌性SD大鼠行双侧卵巢切除术(OVX)后,随机分为安慰剂治疗组(OVX+Veh组)和雌激素替代治疗组(OVX+E组)。ERT 1个月后,Morris水迷宫检测大鼠空间学习和记忆能力;从各组大鼠随机选取10只,透射电子显微镜观察大脑白质及海马内髓鞘的超微结构;Western blot检测大脑白质及海马内髓磷脂碱性蛋白(MBP)及Lingo-1的含量;免疫组化方法检测Lingo-1在大脑白质及海马的分布。结果 OVX+E组大鼠在定位航行实验中的潜伏期显著短于OVX+Veh组大鼠(P0.05);OVX+Veh组大鼠大脑白质和海马存在显著的髓鞘结构变性;OVX+E组大鼠大脑白质和海马中MBP的含量均显著高于OVX+Veh组(P0.05),而OVX+E组大鼠大脑白质和海马中Lingo-1的含量及分布均显著低于OVX+Veh组(P0.05)。结论1个月的ERT对中年卵巢切除大鼠的认知功能及大脑白质和海马内的髓鞘具有明显的保护作用,这种保护作用可能与雌激素下调大脑白质和海马内Lingo-1蛋白的表达有关。     

Effects of ovariectomy and estrogen on skeletal muscle function in growing rats

This study examined the effect of estrogen replacement on soleus muscle size and contractile function in ovariectomized rats during physiological growth. Seven week old female Sprague-Dawley rats were assigned to one of three treatment groups: (1) control animals (SHAM), (2) ovariectomized animals without estrogen replacement (OVX/CO), and (3) ovariectomized animals with 17 beta-estradiol replacement (OVX/E2). OVX/CO and OVX/E2 animals were pair-fed to SHAM animals to rule out the potentially confounding effect of differences in food intake. Rats were sacrificed 4 weeks after surgery and the soleus muscle was removed for analysis. Estrogen replacement reduced body weight, relative body weight gain, and soleus muscle fiber size despite all groups having a similar food intake. Ovariectomy alone had no effect on any of these parameters suggesting that estrogen may inhibit skeletal muscle growth when it is the only ovarian hormone present. Neither ovariectomy nor estrogen replacement affected maximal specific isometric force. Estrogen replacement increased half relaxation time. Ovariectomy resulted in a reduction in time to peak tension that was reversed with estrogen replacement. This reduction was not accompanied by a change in myosin heavy chain composition implying that calcium handling may have been altered. Results from this study suggest that estrogen affects skeletal muscle growth and twitch kinetics.     

内皮源性硫化氢在雌激素抗动脉粥样硬化中的作用及机制

 目的：探讨内皮源性硫化氢（H2S）在雌激素诱导的抗动脉粥样硬化过程中的作用及其机制。方法：在体外培养的人脐静脉内皮细胞（HUVECs）上观察17β-雌二醇（E2）促进H2S快速释放的效应,并进一步观察雌激素受体在此过程中的作用。在去势雌性ApoE–/–C57BL/6小鼠中建立动脉粥样硬化模型,实验分为去势组（OVX）、去势+E2治疗组（OVX+E2）、去势+E2+内源性H2S生成酶抑制剂DL-炔丙基甘氨酸(PPG)治疗组（OVX+E2+PPG）,观察各组大鼠血液中H2S的浓度和动脉粥样斑块大小。结果：E2可以促进HUVECs快速释放H2S,且具有时间效应和浓度效应。雌激素受体α亚型激动剂丙基吡唑三醇(而不是β亚型激动剂二芳丙腈）可以模拟E2促H2S释放效应,雌激素受体拮抗剂ICI 182780可以阻断E2促H2S释放效应。在动物模型上,与OVX相比,OVX+E2组动脉粥样硬化明显改善,血液中H2S浓度升高;而OVX+E2+PPG组动脉粥样硬化无明显改善,H2S浓度无明显差异。结论: 雌激素通过细胞膜上的ERα促进内皮源性H2S的快速释放,H2S在雌激素抗动脉粥样硬化的过程中起着重要作用。     

In vivo release rates of substance P in the preoptic/anterior hypothalamic area of ovariectomized and ovariectomized estrogen-primed rats: correlation with luteinizing hormone and prolactin levels

Push-pull cannulae were implanted into the preoptic/anterior hypothalamic area (POA) of ovariectomized (OVX) rats. After recovery animals were treated with estradiol (E2) or corn oil and they were perfused 3 days later. Substance P (SP) concentrations were measured in 15 min perfusate fractions, blood samples were taken at similar intervals. SP concentration in POA perfusates were readily measurable. Following estrogen priming SP release increased significantly each afternoon prior to the estrogen induced prolactin and luteinizing hormone (LH) surges. No such increase of SP release was observed in OVX rats with constant LH and prolactin levels throughout the day. Mean SP rates in OVX rats were significantly higher in comparison to OVX estrogen-primed rats. These results indicate that SP may be involved in the feedback mechanisms of estrogen on prolactin and LH release. Authenticity of SP in POA perfusates was made probable by high-performance liquid chromatography (HPLC) where synthetic SP eluted at the same retention time as the signal measured in push-pull perfusates.     

雌激素对抑郁症小鼠行为学和脑组织单胺类递质的作用

目的:探讨雌激素低下对抑郁症模型小鼠行为学影响及神经生化机制。方法:清洁级昆明小鼠随机分为假手术组(Sham)、卵巢切除组(OVX)、慢性应激组(CUMS)、卵巢切除+慢性应激组(OVX+CUMS)和雌激素治疗组(E组,0.15 mg/kg),每组10只。给药组于每日应激前1 h,ig给药,其余各组给予等体积生理盐水,共计21 d。采用卵巢切除法(OVX)制备雌激素低下动物模型,采用CUMS法制备抑郁症小鼠模型。观察各组小鼠一般体征,行阴道上皮角化实验,通过旷场实验(OFT)、强迫游泳实验(FST)及体重测试(BWM)观察其行为学变化,采用ELISA法检测脑组织单胺类递质五羟色胺(5-HT)及多巴胺(DA)含量变化。结果:OVX小鼠,阴道细胞涂片未见动情周期变化连续7 d。模型小鼠在第21 d,与Sham组比较,(1)OVX和CUMS小鼠体重增加(P﹤0.01),而OVX+CUMS则体重下降(P﹤0.01);(2)在OVX和CUMS小鼠,OFT水平和垂直运动得分减少(P﹤0.01),而在E组小鼠,OFT水平和垂直运动得分增加(P﹤0.05);(3)在OVX和CUMS小鼠,FST不动时间减少(P﹤0.01),但在E组小鼠,FST不动时间增加(P﹤0.01)。(4)在OVX组小鼠,阴道脱落细胞呈现大量白细胞和少量上皮细胞。在CUMS和OVX小鼠,脑组织5-HT和DA含量减少(P﹤0.01),但在E组小鼠,脑组织中5-HT、DA含量增加(P﹤0.05,P﹤0.01)。结论:小鼠抑郁行为可以由于雌激素低下诱发,并且与脑组织5-HT和DA含量下调有关。补充雌激素可能通过增加单胺类递质5-HT和DA含量在脑组织,从而改善小鼠抑郁行为。     

Sexual dimorphism of GABA release in the medial preoptic area and luteinizing hormone release in gonadectomized estrogen-primed rats

We showed marked sex differences in the GABA outflow in the medial preoptic area of intact rats. To further determine the sexually dimorphic effects of estrogen on the GABA outflow, an in vivo microdialysis study was performed in gonadectomized rats 3-5 days after the estrogen- or cholesterol-priming. Dialysates and sequential blood samples (150 microl each) were simultaneously collected under freely moving conditions. Serum estradiol concentrations at 72 and 84 h after the estrogen capsule implantation were approximately 75 pg/ml in both sexes. Ovariectomized estrogen-primed (OVX+E(2)) rats showed high GABA outflow from the late night through the morning, which was significantly declined until the onset of surge like secretion of luteinizing hormone (LH) in the afternoon (N=7). Ovariectomized cholesterol-primed (OVX+C) rats consistently showed low GABA outflow and high serum LH concentration (N=8). Conversely, orchidectomized estrogen-primed (ORX+E(2)) rats showed high and episodic GABA outflow without any daily changes (N=7), which was significantly greater than orchidectomized cholesterol-primed (ORX+C; N=8) and OVX+C rats. Only OVX+E(2) rats showed significant daily changes in the GABA outflow and serum LH concentration. Fitting with the double cosinor method demonstrated that the acrophase of the GABA outflow in OVX+E(2) rats occurs in the early morning, whereas the acrophases in OVX+C, ORX+C, and ORX+E(2) rats occur at various times of day. The present findings suggest that sex-specific effects of estrogen on the daily GABA release in the medial preoptic area may be involved in the sex difference of LH release in rats.     

In Vivo Effects of Ovarian Steroid Hormones on the Expressions of Estrogen Receptors and the Composition of Extracellular Matrix in the Anterior Cruciate Ligament in Rats

Female athletes have a significantly higher rate of anterior cruciate ligament (ACL) injury than their male counterparts. Sex steroid hormones are considered to have an influence as risk factors for female ACL injuries. We hypothesized that estrogen and progesterone have specific and synergistic influences on the composition of extracellular matrix in ACL. By ovariectomy (OVX) followed by subcutaneous estradiol (E2) and/or progesterone (P4) replacement, 40 female rats were divided into 5 groups: E2, P4, combined E2 and P4 (EP), OVX control, and sham group. After 30 days, using undecalcified sections of knee joints in conjunction with immunofluorescence staining of estrogen receptor α and β (ERα and ERβ), collagen types 1 and 3, and cartilage oligomeric matrix protein (COMP), the immunoreactivities of these proteins in two distinct parts of ACL, proximal and middle portions, were compared semiquantitatively among experimental groups. By E2 replacement, the expressions of ERα in ACL fibroblasts were elevated compared to the OVX group. At the proximal portion, the immunoreactivities of type 1 collagen by E2 replacement, type 3 collagen by P4 replacement, and COMP by E2 or P4 replacement were significantly reduced. At the middle portion, the immunoreactivity of type 3 collagen was significantly elevated by E2 replacement. However, no differences were observed between the sham and OVX groups. These findings suggest that ACL is ER-dependent and that ovarian hormones alter ligament tissue composition, especially at the proximal portion. Female hormonal influences are partly involved in the biological properties of ACL.     

丰富环境对血管性痴呆模型大鼠梨状皮质未成熟神经元表达的影响

BACKGROUND:Researches showed that the enriched environment could improve the cognitive dysfunction of rats with vascular dementia. However, there are few reports regarding its mechanism of action. OBJECTIVE:To explore the effect of enriched environment on the cognitive dysfunction of rats with vascular dementia from the behavioral level.  METHODS:Vascular dementia models were made by permanent ligation of bilateral common carotid arteries and were divided into vascular dementia group (n=8) and enriched environment group (n=12). Vascular dementia group was taken care under conventional breeding environment for 30 days, while the enriched environment group was subjected to the enriched environment for 30 days. Morris water maze test was adapted to test the cognitive function of rats between two groups. Immunohistochemistry and immunoblotting were applied to observe the number of DCX⁺ cells and DCX protein level in both groups. The number of DCX^-labeled cells co-expressing NeuN was observed using immunofluorescence technique. RESULTS AND CONCLUSION:(1) The escape latency in the vascular dementia group was longer than that in the enriched environment group (P < 0.05). The times across the platform was less in the vascular dementia group than that in the enriched environment group (P < 0.05). (2) In comparison with the enriched environment group, the number of DCX-positive cells and its protein level in the piriform cortex were significantly decreased in the vascular dementia group (P < 0.05). (3) The number of DCX/NeuN co-labeled cells in the piriform cortex was significantly less in the vascular dementia group than in the enriched environment group (P < 0.05). (4) These findings suggested that enriched environment could improve the cognitive dysfunction of rats with vascular dementia through promoting the expression and differentiation of the immature neurons.     

雌激素对卵巢摘除大鼠心内神经节细胞胆碱乙酰基转移酶和一氧化氮合酶表达的影响

目的：探讨雌激素对卵巢摘除大鼠心内神经节细胞中神经递质的影响。方法：建立去卵巢(OVX)和雌激素替代疗法动物模型，2个月后用免疫组化结合图象分析方法观察大鼠心内神经节细胞中胆碱乙酰基转移酶(ChAT)和一氧化氮合酶(NOS1)的变化。结果：在OVX大鼠心内神经节细胞中ChAT和NOS1较正常对照组明显减少，雌激素(E2)替代治疗组与正常对照组相比无明显变化，OVX 雌激素受体拮抗剂(TAM)组较正常对照组显著减少，但与OVX组无明显差异。结论：雌激素能上调大鼠(OVX)心内神经节细胞中ChAT和NOS1的表达，雌激素可能够通过对心内神经节细胞中神经递质的调节，间接发挥对心血管功能的调节作用。     

Cellular mechanism of inhibition of osteoclastic resorption of bone and calcified cartilage by long-term pamidronate administration in ovariectomized mature rats

We examined the effects of long-term bisphosphonate (BP, pamidronate) administration at a therapeutic dose (1.5 mg/kg/day) on the distribution, structure, and vacuolar-type H(+)-ATPase expression of osteoclasts, and the resulting trabecular bone volume and structure in ovariectomized (OVX) mature rats. Six-month-old female rats were allocated to sham-operated control, untreated-OVX, and BP-administered OVX groups. Postoperatively, BP was administered intraperitoneally once a day to OVX rats for up to 30 days. On postoperative days 14, 30, and 60, all of the rats were killed and the distal metaphyseal area of the dissected humeri was examined. Quantitative backscattered-electron image analysis revealed that the trabecular bone volume/unit medullary area in untreated OVX rats was significantly (P < 0.05) lower than that in sham-operated controls at 30 and 60 days postoperation. BP administration significantly (P < 0.05) increased trabecular bone volume at 14, 30, and 60 days postoperation in BP-administered OVX rats compared to both sham-operated and untreated OVX rats. Compared to untreated OVX rats, the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts along the bone trabeculae in BP-administered OVX rats was not significantly decreased on days 14 and 30, but was significantly decreased on day 60. Ultrastructurally, BP administration caused the disappearance of both the ruffled border (RB) and the clear zone (CZ) structures, and decreased the expression of vacuolar-type H(+)-ATPase in most osteoclasts, but did not significantly induce apoptosis of osteoclasts detected by the terminal dUTP nick end-labeling (TUNEL) method. Our results suggest that long-term BP administration significantly reduces bone and calcified cartilage resorption through impairment of the structure and bone-resorbing function of osteoclasts, and thereby effectively maintains trabecular bone volume and structure in ovariectomy-induced acute estrogen deficiency in mature rats.     

17β-雌二醇对去势大鼠子宫内膜厚度的影响

目的:探索外源性使用雌激素对去势后大鼠子宫内膜厚度的影响。方法:96只雌性成年SD大鼠,随机分为假手术组、模型组和17β-雌二醇(17β-estradiol,E2)治疗组,模型组和E2治疗组行去势手术,并且E2组给予不同剂量、不同时间的E2背部皮下注射后处死,假手术组于动情前期处死,取子宫标本,行HE染色,在200倍显微镜下随机选取六个位置拍照,测量子宫腔上皮厚度。结果:去势E2治疗组大鼠子宫的发育与替代雌激素的用量呈明显的量效关系及时效关系。E2浓度在6μg.只-1,连续使用2 d时,去势大鼠子宫内膜形态学检查与假手术组组基本相似,子宫腔上皮厚度比假手术组大鼠增加8%,可认为是合理的雌激素替代剂量与时间。