Combined Effects of Phytoestrogen Genistein and Silicon on Ovariectomy-Induced Bone Loss in Rat

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group (P < 0.05). At the same time, the treatment with genistein and/or silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups (P < 0.05). The results above indicate that genistein and silicon have synergistic effects on bone formation in ovariectomized rats.     

Cistanches Herba aqueous extract affecting serum BGP and TRAP and bone marrow Smad1 mRNA, Smad5 mRNA, TGF-β1 mRNA and TIEG1 mRNA expression levels in osteoporosis disease

We studied molecular mechanism of Cistanches Herba aqueous extract (CHAE) in ovariectomized (OVX) rats, as an experimental model of postmenopausal osteoporosis. Female rats were either sham-operated or bilaterally OVX; and at 60 days postoperatively. The OVX group (n = 8) received an ovariectomy and treatment with normal saline for 90 days commencing from 20th post ovariectomy day. The ovariectomized +CHAE (OVX + CHAE) group (n = 8) received an ovariectomy and were treated with Cistanches Herba aqueous extract of 100 mg/kg body weight daily for 90 days commencing from 22nd post ovariectomy day. The ovariectomy +CHAE (OVX + CHAE) group (n = 8) received an ovariectomy, and were treated with the of 200 mg/kg body weight daily for 90 days commencing from 20th post ovariectomy day. Serum BGP and TRAP, E2, FSH and LH level, bone marrow Smad1, Smad5, TGF-β1 and TIEG1 mRNA expression levels were examined. Results showed that serum BGP and TRAP, FSH and LH levels were significantly increased, whereas E2, Smad1, Smad5, TGF-β1 and TIEG1 mRNA and proteins expression levels were significantly decreased in OVX rats compared to sham rats. 90 days of CHAE treatment could significantly decrease serum BGP and TRAP, FSH and LH levels, and increase E2, Smad1, Smad5, TGF-β1 and TIEG1 mRNA and proteins expression levels in OVX rats. It can be concluded that CHAE play its protective effect against OVX-induced bone degeneration partly by regulating some bone metabolism related genes, e.g. Smad1, Smad5, TGF-β1 and TIEG1.     

Estrogen stimulates PTHrP but not PTH/PTHrP receptor gene expression in the kidney of ovariectomized rat

The aim of the present study was to test the hypothesis that the decreased renal tubular reabsorption of calcium observed in estrogen deficiency is associated with a local regulation of either PTHrP or PTH/PTHrP receptor genes in the kidney. Rats were randomly sham-operated (S) or ovariectomized receiving either vehicule (OVX) or 4 μg E2/kg/day (OVX+E4) or 40 μg E2/kg/d (OVX+E40) during 14 days using alzet minipumps. Plasma PTH and calcium levels were lower in untreated OVX animals than in all other groups (P < 0.01). Plasma PTH was higher in OVX+E40 than in OVX+E4 (P < 0.05). PTHrP mRNA expression in the kidney was unaffected by ovariectomy but was increased in OVX+E40 (0.984 ± 0.452 for PTHrP/GAPDH mRNAs expression vs. 0.213 ± 0.078 in sham, P < 0.01). PTH/PTHrP receptor mRNA expression and the cAMP response of renal membranes to PTH were unaffected by ovariectomy and estrogen substitution. In conclusion, renal PTHrP and PTH/PTHrP receptor mRNAs are not modified by ovariectomy. However, 17β-estradiol increases renal expression of PTHrP mRNA without evident changes in its receptor expression and function. This may help to explain the pharmacological action of estrogen in the kidney, especially how it prevents the renal leak of calcium in postmenopausal women. J. Cell. Biochem. 70:84–93, 1998. © 1998 Wiley-Liss, Inc.     

Manganese Supplementation Reduces the Blood Cholesterol Levels in Ca-Deficient Ovariectomized Rats

Manganese (Mn) is an essential element for normal development and bodily functions in humans. In the present study, we examined whether Mn supplementation can alter the serum lipid parameters and liver function in Ca-deficient ovariectomized (OVX) rats. Sixty female Sprague–Dawley rats (6 weeks) were divided into five groups and bred for 12 weeks: sham-operated control group (Sham), OVX Ca deficiency group (OLCa) with Ca-deficient diet (0.1% Ca modified AIN-93N diet), OVX Ca deficiency and Mn supplementation group (OLCaMn), OVX with adequate Ca group (OACa; 0.5% Ca AIN-93N diet), and OVX with adequate Ca and Mn supplementation group (OACaMn). A low Ca diet increased the liver weight and serum levels of GOT, GPT, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol in OVX rats. Mn supplementation decreased these parameters in Ca-deficient OVX rat. The results of our study suggest Mn supplementation results in reductions of the blood cholesterol levels, which show an increase due to Ca deficiency in OVX rats.     

Using three-point bending to evaluate tibia bone strength in ovariectomized young mice

It is well known that estrogen deficiency induces a deterioration of bone strength in aged females. The aim of this study is to determine the effect of estrogen depletion on tibia bone strength in sexually mature mice that are still undergoing skeletal maturation. At 8 weeks of age, C57BL/6 female mice underwent an ovariectomy (OVX) or sham (SHAM) surgery. Mice were killed at 2, 4, or 8 weeks post-surgery. Tibia length and cross-sectional area continued to increase in both treatment groups until 4 weeks post-surgery. Compared to SHAM mice, OVX mice demonstrated a significant reduction in uterine weight and plasma estrogen levels. Three-point bending was used to quantify the mechanical properties (breaking point, stress, stiffness, and elasticity) of the tibia. The tibias from the SHAM mice had a higher breaking point than all the age-matched OVX mice. At 8 weeks post-surgery, the tibias from the SHAM mice demonstrated higher elasticity, stress, and stiffness than the younger SHAM mice and the age-matched OVX mice. Compared to the SHAM mice, our study suggests that (1) there is a reduction in the mechanical strength of tibias from young OVX mice, and (2) the greatest decline in tibia strength of the OVX mice was once they reached skeletal maturity.     

Protective Effects of Gallium, Germanium, and Strontium Against Ovariectomized Osteoporosis in Rats

The effects of trace elements of gallium (Ga), germanium (Ge), and strontium (Sr) on ovariectomized (OVX) osteopenic rats were studied in this paper. The urine calcium content, serum calcium, and phosphorus contents, bone mineral content, mineral dissolution, and mechanical strength of the osteopenic rats were analyzed respectively. After the rats were fed with Ga, Ge, and Sr diet for 8 weeks, respectively, the urine calcium content decreased (P?<?0.01). Plasma calcium and phosphate concentrations decreased in the order of OVX group?>?Ge group?>?Sr group?>?Ga group?>?Sham group. Mineral content increased in the order of OVX group?<?Ge group?<?Sr group?<?Ga group?<?Sham group. A dramatic decrease in calcium solubility was found both in the gallium and strontium treated animals (P?<?0.05). However, the same result did not occur in germanium treated groups. The data provide an important proof of concept that gallium and strontium might be a new potential therapy for the management of postmenopausal osteoporosis in humans.     

Estrogen responsiveness of renal calbindin-D28k gene expression in rat kidney

In women, calcium excretion in the urine rises after menopause and falls with estrogen replacement therapy. The amount of calcium lost in the urine following estrogen therapy is less than should occur based on changes in serum calcium and the amount of calcium filtered by the kidney. This suggests there may be a direct effect of estrogen therapy to increase renal calcium reabsorption. Calbindin D_28k is a putative calcium ferry protein located in the distal renal tubules which has been shown to increase transcellular calcium transport. We proposed that estrogen loss after menopause may diminish gene expression of renal calbindin D_28k and subsequently diminish renal calcium reabsorption. We used the ovariectomized rat model of estrogen deficiency to investigate changes at the messenger RNA level of calbindin D_28k in ovariectomized rats (OVX), sham ovariectomized rats (S-OVX), and estrogen treated ovariectomized rats (E-OVX). We have demonstrated that ovariectomy in rats diminishes the gene expression of renal calbindin D_28k. The mRNA levels were approximately three times lower in OVX rats than S-OVX rats. Administration of 17β estradiol to OVX rats produced a significant increase in mRNA level to greater than the S-OVX rats by 4 h. Measurement of serum 1,25 dihydroxyvitamin D₃ showed lower level in OVX rats than S-OVX rats but no significant change in E-OVX animals. In conclusion, our results indicate that estrogen increases renal calbindin D_28k mRNA levels, by a mechanism independent of changes in 1,25 dihydroxyvitamin D₃. This may result in increased expression of calbindin D_28k protein which may have a role in reducing renal calcium excretion. J. Cell. Biochem. 65:340–348. © 1997 Wiley-Liss, Inc.     

Changes in central and peripheral inflammatory responses to lipopolysaccharide in ovariectomized female rats

Obesity leads to increases in inflammatory responses in a site-specific manner. Ovariectomized animals, usually used as menopause models, exhibit obesity; however, their inflammatory responses have not been fully examined. In the present study, we investigated whether ovariectomy had site-specific effects on inflammatory responses. First, fever and anorectic responses to systemic injections of lipopolysaccharide (LPS) (500 μg/kg, i.p.) were compared between ovariectomized rats (OVX) and sham-operated female rats (Sham). Inflammatory cytokines at the central and peripheral levels were also compared under saline-injected and LPS-injected conditions. Body weight in OVX was significantly higher than in Sham. The anorectic responses (reduction of body weight and food intake) to LPS were higher in OVX than in Sham. In the hypothalamus, all of the examined cytokine (IL-1β, TNF-α and IL-6) mRNA levels in OVX were higher than in Sham under the LPS-injected condition. On the other hand, in serum and adipose tissue, only IL-6, not IL-1β and TNF-α, levels in OVX were significantly higher than those in Sham under the LPS-injected condition. Second, responses to central (intracerebroventricular) injections of LPS (500 ng) were compared between OVX and Sham. The result was that the fever response in OVX was more evident than in Sham. Finally, responses to systemic injections of LPS (500 μg/kg, i.p.) were compared between OVX (OVX-oil) and OVX with estradiol (E) and progesterone (P) supplementation (OVX-EP). The anorectic responses and hypothalamic cytokine mRNA levels under LPS-injected condition were not different between OVX-oil and OVX-EP. These results indicate that ovariectomy enhances inflammatory responses, especially at the central level compared with the peripheral level. As supplementation of E and P could not attenuate the anorectic and cytokine responses to LPS, the deficiency of gonadal steroids might not be directly involved in the increase of inflammatory responses in OVX.     

High-impact exercise strengthens bone in osteopenic ovariectomized rats with the same outcome as Sham rats.

The effect of jump exercise on middle-aged osteopenic rats was investigated. Forty-two 9-mo-old female rats were either sham-operated (Sham) or ovariectomized (OVX). Three months after surgery, the rats were divided into the following groups: Sham sedentary, Sham exercised, OVX sedentary, and OVX exercised. Rats in the exercise groups jumped 10 times/day, 5 days/wk, for 8 wk, with a jumping height of 40 cm. Less than 1 min was required for the jump training. After the experiment, the right tibia and femur were dissected, and blood was obtained from each rat. OVX rats were observed to have increased body weights and decreased bone mass in their tibiae and femurs. Jump-exercised rats, on the other hand, had significantly increased tibial bone mass, strength, and cortical areas. The bone mass and strength of OVX exercised rats increased to approximately the same extent as Sham exercised rats, despite estrogen deficiency or osteopenia. Our data suggest that jump exercise has beneficial effects on lower limb bone mass, strength, bone mineral density, and morphometry in middle-aged osteopenic rats, as well as in Sham rats.     

雌激素对SD大鼠肾脏缺血再灌注肾小管上皮细胞Cx43蛋白表达的影响

为了探讨雌激素（estrogen,E2）对SD大鼠肾脏缺血再灌注（ischemia-reperfusion,I/R）肾小管上皮细胞Cx43蛋白表达的影响,选取32只健康雌性SD大鼠作为实验材料,所有雌性SD大鼠均先实施去卵巢（ovariectomized,OVX）处理,之后32只雌性OVX SD大鼠随机分为OVX组、OVX+假手术组、OVX+I/R组、OVX+I/R+E2组,每组8只。去卵巢2周后,OVX组不进行任何处理,OVX+Sham组进行假手术处理,OVX+I/R组进行缺血再灌注处理,OVX+I/R+E2组在进行缺血再灌注处理前,连续3 d予以雌激素处理。通过比较各组SD大鼠血肌酐水平、尿素氮水平、肾脏HE染色及Paller评分,评价肾脏组织损伤程度,并通过免疫组化和蛋白印迹法分析各组SD大鼠肾小管上皮细胞中Cx43蛋白的表达位置及水平。与OVX组比较,OVX+I/R组血清BUN、SCr水平明显升高（P<0.05）;与OVX+I/R组比较,OVX+I/R+E2组血清BUN、SCr水平明显降低（P<0.05）。HE染色观察发现,与OVX组相比,OVX+I/R组肾小管扩张...     

Ovariectomy worsens secondary hyperparathyroidism in mature rats during low-Ca diet

Estrogen deficiency impairs intestinal Ca absorption and induces bone loss, but its effects on the vitamin D-endocrine system are unclear. In the present study, calciotropic hormones levels, renal vitamin D metabolism, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]-dependent intestinal calcium absorption, and bone properties in 3-mo-old sham-operated (sham) or ovariectomized (OVX) rats fed either a normal-Ca (NCD; 0.6% Ca, 0.65% P) or a low-Ca (LCD; 0.1% Ca, 0.65% P) diet for 2 wk were determined. LCD increased serum 1,25(OH)2D3 levels in both sham and OVX rats. Serum parathyroid hormone [PTH(1-84)] levels were highest in OVX rats fed LCD. Renal 25-hydroxyvitamin D1alpha-hydroxylase (1-OHase) protein expression was induced in both sham and OVX rats during LCD, while renal 1-OHase mRNA expression was highest in OVX rats fed LCD. Renal vitamin D receptor (VDR) and mRNA expressions in rats were induced by ovariectomy in rats fed NCD but suppressed by ovariectomy in rats fed LCD. The induction of intestinal calcium transporter-1 and calbindin-D9k mRNA expressions by LCD were not altered by ovariectomy. As expected, bone Ca content, cancellous bone mineral density, and bone strength index in proximal metaphysis of rat tibia were reduced by both ovariectomy and LCD (P<0.05) as analyzed by two-way ANOVA. Taken together, the data demonstrate that ovariectomy alters the responses of circulating PTH levels, renal 1-OHase mRNA expression, and renal VDR expression to LCD. These results suggest that estrogen is necessary for the full adaptive response to LCD mediated by both PTH and 1,25(OH)2D3.     

The RIP1–RIP3 Complex Mediates Osteocyte Necroptosis after Ovariectomy in Rats

Osteocyte apoptosis has been reported to play a central role in bone remodeling. In addition to apoptosis, other mechanisms may be involved in osteocyte loss. This study aimed to investigate the effect of necroptosis on osteocytes in ovariectomized (OVX) rats. Ninety-six female Sprague-Dawley rats were randomly divided into an OVX group and a sham group. At 0, 4, 8 and 12 weeks after surgery, specimens from each group (n = 12 each) were harvested. Bone mineral density (BMD) and body weight were measured. Transmission electron microscopy (TEM) and micro-CT were used to observe the changes in cellular morphology and bone microarchitecture induced by estrogen deficiency. Osteocyte apoptosis and necroptosis were evaluated via TUNEL and immunofluorescence staining for active caspase-3. At 8 weeks after ovariectomy, a greater number of osteocytes with typical necrotic morphological features were TUNEL positive but negative for active caspase-3. Western blotting, quantitative real-time PCR and immunofluorescence assessments demonstrated that the levels of receptor-interacting serine/threonine protein kinase 1 (RIP1) and RIP3 in osteocytes were significantly increased at 8 weeks after ovariectomy. These data are the first to suggest that necroptosis accelerates osteocyte loss under conditions of estrogen deficiency-induced osteoporosis in OVX rats. These findings provide evidence of a potential mechanism through which osteocyte necroptosis is associated with postmenopausal osteoporosis.     

去卵巢致骨质疏松症大鼠腺垂体FS细胞中Cx43、S-100蛋白表达--激光扫描共聚焦显微镜观察

检测间隙连接蛋白Cx43、神经组织蛋白S-100在去卵巢致骨质疏松症(OVX-OP)大鼠腺垂体滤泡星形细胞(FS细胞)中的表达.实验采用10月龄未孕产SD雌性大鼠40只,随机均分为卵巢切除组(OVX组,n=20)和假性手术对照组(Sham组,n=20).于术后6周末用双能X线骨吸收测量法(DEXA)测量大鼠全身及腰椎4-6(L4-6)骨密度(BMD).取两组大鼠垂体,制成连续切片.应用FITC标记的IgG探针,对腺垂体组织中Cx43和S-100进行间接免疫荧光染色,并用激光扫描共聚焦显微镜(LSCM)定位和定量分析腺垂体FS细胞中Cx43、S-100的表达.结果发现,术后6周末OVX组大鼠全身及L4-6BMD均明显低于Sham组值(P<0.01,P<0.01).Cx43阳性荧光反应主要定位于相邻的FS细胞的胞浆中和/或胞膜上.OVX组Cx43阳性表达荧光强度和表达阳性率均显著低于Sham组(P<0.01).S-100蛋白表达定位于FS细胞的胞浆中,两组间S-100阳性表达荧光强度和表达阳性率无显著差异(P>0.05).本研究提示,SD大鼠OVX术后6周出现骨质疏松变化;OVX大鼠腺垂体FS细胞数量无明显变化、而Cx43表达显著下降,后者的变化可能与大鼠OVX-OP发生相关.     

Effects of eccentric exercise training on cortical bone and muscle strength in the estrogen-deficient mouse.

The purpose of this study was to determine whether eccentrically biased exercise training could attenuate changes in muscle and bone function associated with estrogen deficiency in the mouse model. Four groups of ICR mice were used: control (Con), sham ovariectomized (Sham), ovariectomized (OVX), and ovariectomized + high-force resistance training (OVX+Train). All groups except Con were implanted with a nerve cuff surrounding the peroneal nerve to stimulate the left ankle dorsiflexors. Training consisted of 30 stimulated eccentric contractions of the left ankle dorsiflexors at approximately 150% of peak isometric torque every third day for 8 wk. After the training period, groups were not significantly different with regard to peak torque or muscle size. However, the tibial midshaft of the trained leg in the OVX+Train mice exhibited greater stiffness (+15%) than that in the untrained OVX mice, which could not be explained by changes in cross-sectional geometry of the tibia. Scaling of bone mechanical properties to muscle strength were not altered by ovariectomy or training. These data indicate that eccentric exercise training in adult mice can significantly increase bone stiffness, despite the absence of ovarian hormones.     

Improving effect of feeding with a phosphorylated guar gum hydrolysate on calcium absorption impaired by ovariectomy in rats

We have previously reported that a phosphorylated guar gum hydrolysate (P-GGH) promoted calcium absorption and the accumulation of bone calcium in rats. We now investigate the effect of P-GGH (50 g/kg of diet) on the intestinal calcium absorption and bones of ovariectomized (OVX) rats in comparison with sham-operated rats over a six-week ingestion period. The apparent calcium absorption was decreased by aging and ovariectomy in the rats fed on the control and GGH diets (50 g/kg of diet), but not in the rats fed on the P-GGH diet. The absorption was higher in the P-GGH group than in the GGH and control diet groups in the fourth and sixth weeks after feeding the test diets to OVX rats. Femoral calcium and strength were decreased by OVX in the rats fed on the control and GGH diets, but not in the rats fed on the P-GGH diet. The values of these parameters were higher in the P-GGH group than in either the control or GGH group of OVX rats. The amount of soluble calcium in the ileal contents was higher in the P-GGH group than in the control and GGH groups. These results indicate that P-GGH may be useful for preventing the reduction of intestinal calcium absorption and bone in the condition of estrogen deficiency.     

Increased PELP1 expression in rat periodontal ligament tissue in response to estrogens treatment

Estrogens and their receptors are important factors involved in periodontal ligament (PDL) tissue health. As a regulator of estrogen receptors (ER), the proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) may play a role in alveolar bone formation and PDL homeostasis. The aim of the present study was to observe PELP1 expression in rat PDL tissue during estrogen levels manipulations. Twenty-one 8-week old normal female Sprague–Dawley rats were randomly divided into three equal groups: sham-operated controls, ovariectomized (OVX) group, and OVX given 17β-estradiol intraperitoneally (OVX + E₂) for 16 weeks. PELP1 expression was down-regulated in the OVX group and was up-regulated in the OVX + E₂ group. Periodontal ligament fibroblast cells (PDLFCs) were isolated from PDL tissue, and characterized by immunohistochemical staining. Estradiol treatment of PDLFCs induced PELP1 protein level compared to untreated cells. PELP1 mRNA expression in estradiol-treated cells was relatively low at the beginning of treatment and then steadily increased from hour 4. In conclusion, results indicate that PELP1 is expressed in rat PDL tissue and PDLFCs, and that its expression is up-regulated during estrogen treatment.     

Effects of Multi-Deficiencies-Diet on Bone Parameters of Peripheral Bone in Ovariectomized Mature Rat

Many postmenopausal women have vitamin D and calcium deficiency. Therefore, vitamin D and calcium supplementation is recommended for all patients with osteopenia and osteoporosis. We used an experimental rat model to test the hypothesis that induction of osteoporosis is more efficiently achieved in peripheral bone through combining ovariectomy with a unique multi-deficiencies diet (vitamin D depletion and deficient calcium, vitamin K and phosphorus). 14-week-old Sprague-Dawley rats served as controls to examine the initial bone status. 11 rats were bilaterally ovariectomized (OVX) and fed with multi-deficiencies diet. Three months later the treated group and the Sham group (n = 8) were euthanized. Bone biomechanical competence of the diaphyseal bone was examined on both, tibia and femur. Image analysis was performed on tibia via µCT, and on femur via histological analysis. Lower torsional stiffness indicated inferior mechanical competence of the tibia in 3 month OVX+Diet. Proximal metaphyseal region of the tibia showed a diminished bone tissue portion to total tissue in the µCT despite the increased total area as evaluated in both µCT and histology. Cortical bone showed higher porosity and smaller cross sectional thickness of the tibial diaphysis in the OVX+Diet rats. A lower ALP positive area and elevated serum level of RANKL exhibited the unbalanced cellular interaction in bone remodeling in the OVX+Diet rat after 3 month of treatment. Interestingly, more adipose tissue area in bone marrow indicated an effect of bone loss similar to that observed in osteoporotic patients. Nonetheless, the presence of osteoid and elevated serum level of PTH, BGP and Opn suggest the development of osteomalacia rather than an osteoporosis. As the treatment and fracture management of both osteoporotic and osteomalacia patients are clinically overlapping, this study provides a preclinical animal model to be utilized in local supplementation of minerals, drugs and growth factors in future fracture healing studies.     

Chronic GPER activation prevents ischemia/reperfusion injury in ovariectomized rats

During menopause women are exposed to an increase in cardiovascular risk. G protein-coupled estrogen receptor (GPER) is known to mediate several of the protective effects of such hormones. G1 was described as a selective and synthetic agonist for GPER. The aim of the present research is to evaluate the effect of a chronic treatment with G1 in ovariectomized (OVX) rats exposed to ischemia/reperfusion (I/R). Considering the hypothesis that an impaired mitochondrial state could be involved in the alterations produced in OVX rats, other objective of this study was to investigate it in an isolated preparation. Three months old rats were assigned to undergo either bilateral ovariectomy or sham operation. The OVX rats were randomly treated during one month with either G1 or vehicle. Cardiac mitochondria from OVX rats showed a depolarized membrane potential and a decreased calcium retention capacity in comparison with Sham rats, which were prevented by chronic G1 treatment. I/R caused a higher decrease of left ventricular developed pressure and a higher increase of left ventricular end diastolic pressure in OVX compared to Sham hearts. These altered mechanical parameters were prevented by G1. The induced infarct size was significantly higher in OVX, which was reduced by G1 treatment. These results indicate that the mitochondrial state in OVX rats is impaired, accompanied by an altered mechanical response after ischemia and reperfusion injury, which was effectively prevented with chronic treatment with G1. The present study may provide further insights for the potential development of a therapy based on the GPER modulation.     

仙灵骨葆对骨质疏松大鼠OPG/RANK/RANKL 表达的影响

目的:观察仙灵骨葆治疗骨质疏松模型大鼠后,对大鼠体内OPG/RANKL/RANK表达的影响。方法:卵巢摘除法建立SD大鼠骨质疏松模型,设立假手术组、对照组(单纯去卵巢组)、雌激素组(给予17β-雌二醇)和治疗组(给予仙灵骨葆)。术后1周开始给药,给药12周后检测各组大鼠股骨骨密度,ELISA法检测血清中OPG/RANKL含量,RT-PCR检测骨组织中OPG/RANK/RAN-KL mRNA表达,免疫组化检测骨组织中RANK的表达。结果:对照组大鼠骨密度显著低于假手术组;治疗组和雌激素组大鼠O-PG表达显著高于对照组,RANK及RANKL的表达显著低于对照组。结论:采用卵巢摘除法成功建立大鼠骨质疏松模型;仙灵骨葆可促进骨质疏松大鼠OPG的表达,并抑制RANK及RANKL的表达,对骨质疏松模型大鼠有治疗作用。     

针刺对去卵巢大鼠脑内胆碱乙酰转移酶基因表达的影响

本工作旨在探讨雌激素对脑内乙酰胆碱生成的影响和电针刺激“足三里”穴对去卵巢大鼠脑内乙酰胆碱生成的调整作用。实验选用成年Wistar雌性大鼠,将动物分为正常对照组(INT)、去卵巢组(OVX)和去卵巢针刺组(OVX AC)。用放射免疫分析方法测定血中雌二醇含量,采用RT-PCR方法获得大鼠脑内胆碱乙酰转移酶(ChAT)mRNA的逆转录表达产物——cDNA,用琼脂糖凝胶电泳方法检测,并通过原位杂交方法观察海马ChAT mRNA阳性神经元的表达,然后用计算机图像分析系统进行统计分析。实验结果显示：去卵巢组大鼠体内雌激素水平明显降低,脑内ChAT mRNA的RT-PCR产物和海马ChAT mRNA阳性表达产物的平均面积、平均积分光度值均明显减少,与对照组和针刺组比较有显著性差异;去卵巢针刺“足三里”穴组与去卵巢组相比,大鼠血中雌激素水平明显升高,脑内ChAT mRNA RT-PCR产物明显增多,海马的ChAT mRNA表达阳性神经元增多。以上结果提示：脑内ChAT基因表达与体内雌激素水平有密切关系,去卵巢后针刺“足三里”穴对ChAT的调节作用可能是针刺增强脑内乙酰胆碱含量的机制之一。