Ovariectomy Aggravated Sodium Induced Hypertension Associated With Altered Platelet Intracellular Ca in Dahl Rats

Our purpose was to determine the effect of ovariectomy on intracellular Ca²⁺ mobilization and platelet aggregation in sodium induced hypertension. At the age of 12 weeks ovariectomy or sham operation was performed in female Dahl-Iwai salt sensitive rats on a 0.3% NaCl diet. Four weeks later we assessed the effects of ovariectomy and an 8% NaCl diet on agonist induced intracellular Ca²⁺ mobilization in fura-2 loaded platelets and platelet aggregation. Ovariectomy enhanced the increase of systolic blood pressure and heart to body weight ratio on an 8% NaCl diet. However, thrombin evoked intracellular Ca²⁺ was not correlated with systolic blood pressure (r = −0.338, P = .17), and was lowered by sodium loading and ovariectomy (360 ± 23 to 285 ± 9, 296 ± 10 nmol/L, P < .05). Furthermore, the ionomycin induced intracellular calcium fraction in the absence of external Ca²⁺ that reflected internal Ca²⁺ discharge capacity was reduced in ovariectomized rats compared with sham operated rats on an 8% NaCl diet (648 ± 15 v 768 ± 35 nmol/L, P < .05). The internal Ca²⁺ discharge capacity was inversely correlated with systolic blood pressure (r = −0.506, P = .03). In addition to the decreased internal Ca²⁺ discharge capacity, intracellular Ca²⁺-independent platelet aggregation by phorbol 12-myristate 13-acetate, a protein kinase C activator, was significantly enhanced in hypertensive rats. We concluded that ovariectomy enhanced sodium induced hypertension associated with the decreased internal Ca²⁺ discharge capacity and increased platelet aggregation in Dahl-Iwai salt-sensitive rats.     

雷洛昔芬对去卵巢大鼠血脂的影响

目的探讨选择性雌激素受体调节剂雷洛昔芬对去卵巢大鼠血脂的影响。方法将40只3月龄雌性SD大鼠随机分为5组,去卵巢组、假手术组、雌激素组、小剂量雷洛昔芬组(小剂量组)和大剂量雷洛昔芬组(大剂量组),每组8只。治疗3个月后,测量各组治疗前后体重、血压和血脂的变化。结果去卵巢组TC和LDL-C显著高于其他4组(P<0.01),雌激素组与假手术组比较无统计学差异(P>0.05),与小剂量组比较,大剂量组能更进一步降低TC和LDL-C(P<0.05)。去卵巢组TG与假手术组比较稍有升高,但无统计学差异,雌激素组TG高于假手术组和大、小剂量组(P<0.05)。去卵巢组HDL-C明显低于其他4组(P<0.01),雌激素组HDL-C与假手术组比较无统计学差异(P>0.05),与小剂量组比较,大剂量组能更进一步升高HDL-C(P<0.05)。结论雷洛昔芬可改善去卵巢大鼠的脂代谢状况,有助于降低绝经后的心血管危险。     

Effects of estrogen deficiency and low bone mineral density on healthy knee cartilage in rabbits

The purpose of this study was to compare the effects of estrogen deficiency and bone mass loss on normal knee cartilage in mature rabbits. Bilateral ovariectomy (OVX) was performed in 13 rabbits, 6 of which also received systemic glucocorticoid for 4 weeks. Seven additional healthy rabbits were used as controls. Bone mineral density (BMD) was measured by dual X‐ray absorptiometry in lumbar spine, knee, and subchondral bone of the knee at baseline and 22 weeks after OVX. After sacrifice, the knees were dissected, macroscopy was assessed, and histological cartilage abnormalities were evaluated according to the Mankin score. Correlations of Mankin with BMD at different regions were also performed. When compared to baseline, differences in BMD were only found in spine and knee of the animals receiving glucocorticoids. All the animals subjected to OVX had a significantly higher Mankin score than controls. Mankin was upper in OVX animals receiving glucocorticoids, but differences were not significant. The Mankin score was inversely related with BMD in lumbar spine (r = ?0.67; p < 0.01). Although low bone mineral density contributes to the minor osteoarthritic alterations observed in our model, estrogen deficiency itself seems to act directly to induce the main pathogenic effects in healthy cartilage of the rabbit. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:812–818, 2010     

Development of a synthetic peptide-based tartrate-resistant acid phosphatase radioimmunoassay for the measurement of bone resorption in rat serum

Selective markers of bone turnover provide a convenient and reproducible alternative to the complex and expensive histochemical techniques used commonly to study the effect of pharmacological agents and the pathogenesis of bone disease in the ovariectomized (OVX) rat model. One marker, which has been specifically linked to terminally differentiated osteoclasts and, thus, provides useful insight at cellular levels, is type-5 tartrate-resistant acid phosphatase (TRACP). We describe the development of a TRACP radioimmunoassay (RIA), which requires synthetic peptide for antibody development. To develop the RIA, polyclonal antibodies were generated in goats against a synthetic peptide, DPSVRHQRKCY, corresponding to amino acid residues 267–275 of the rat type-5 TRACP sequence. In the RIA, 50 μl of rat serum, 100 μl of goat anti-TRACP antibodies, and 100 μl of tracer were incubated overnight. The antibody-bound fraction was separated, counted, and unknown values were calculated by comparison with the peptide calibrator. Rat serum shows parallelism with the synthetic peptide calibrator used in the RIA. The sensitivity of the RIA was 24.7 μg/l, and the measuring range was 19–2476 μg/l. The average intra-assay coefficients of variation for (CV) two controls were less than 7%. The average dilution and spike recoveries were 107% and 87%, respectively. We applied our peptide-based RIA to study bone resorption in an OVX rat model. TRACP concentrations in serum in 12-week-old OVX Sprague Dawley rats were 14%–22% (P < 0.05) higher than those in the sham-operated rats, and TRACP concentrations in OVX rats treated with estradiol were 24%–32% lower (P < 0.01) than those in the vehicle-treated OVX group. Similarly, as compared with those in OVX rats, TRACP concentrations decreased to those of sham levels in OVX rats receiving 10 μg/kg per day of alendronate for 10 days. In addition, the TRACP levels determined by RIA showed a significant correlation with serum C-telopeptide (type-I collagen) concentrations (r = 0.56; P < 0.001) measured by an enzyme-linked immunosorbent assay (ELISA) developed earlier for the rat model. In conclusion, we have developed a TRACP RIA that could be used to monitor the rate of bone resorption in the rat model. Received: June 18, 2001 / Accepted: October 26, 2001     

Prolonged intake of fermented soybean (natto) diets containing vitamin K2 (menaquinone-7) prevents bone loss in ovariectomized rats

The effect of the prolonged intake of dietary vitamin K₂ (menaquinone-7, MK-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 μg MK-7/100 g diet) without or with supplemental MK-7 (containing 14.1 or 18.8 μg of MK-7 as total per 100 g diet) for 150 days. Feeding produced a significant elevation of MK-7 concentration in the serum of OVX rats. In this case, the femoral MK-4 content was significantly increased, but MK-7 was not detected in the femoral tissues, indicating degradation of MK-7. Serum γ-carboxylated osteocalcin concentration was significantly decreased by OVX. This decrease was significantly prevented by the feeding of the natto diets with supplemental MK-7 (18.8 μg/l00 g diets). OVX caused a significant decrease in femoral dry weight, femoral calcium content, and mineral density. These decreases were significantly prevented by feeding with diets containing natto with MK-7 (total, 18.8 μg/100 g diets). This study demonstrates that the prolonged intake of natto dietary including MK-7 has a preventive effect on bone loss induced by OVX. Dietary MK-7 may be useful in the prevention of osteoporosis. Received: June 18, 1999 / Accepted: Sept. 3, 1999     

XW630对去卵巢大鼠骨质疏松的作用(英文)

目的:研究XW630对去卵巢大鼠骨质疏松的影响。方法:血清E_2和骨钙素(BGP)浓度用放射免疫测定法。骨组织计量学用四环素内标法。结果:去卵巢后,血清E_2水平下降61.9％,子宫减轻72.7％,动情次数减少63.6％。XW630治疗13周后,血清BGP浓度增加75.7％,动情次数略增加,但低于假手术组,血清E_2浓度及子宫重量无明显变化。与OVX组相比,XW630组骨组织计量学指标TBV/TTV,TBV/SBV和MTPD增加;Sfract(s),Sfract(d),TOS和Svf增加,OMP缩短。结论:XW630增加骨激活频率、骨小梁连接性、稳定性和张力。表明XW630促进骨形成、抑制骨吸收,对生殖系统无影响。     

Guidelines to determine the route of oophorectomy with hysterectomy

OBJECTIVES: Our purpose was to determine whether there is adequate visibility and access for transvaginal oophorectomy in most patients and the success rate of the transvaginal approach. The final goal was to establish objective guidelines for choosing the route of oophorectomy with hysterectomy. STUDY DESIGN: Patients underwent laparoscopy-assisted vaginal hysterectomy (n = 91) or vaginal hysterectomy (n = 875). Ovarian removal, either unilateral (n = 97) or bilateral (n = 187), was carried out for clinical or prophylactic reasons. The accessibility of the ovaries for transvaginal removal was assessed by stretching the infundibulopelvic ligament and grading the position of the ovaries from 0 (no descent) to III (descent past the hymenal ring with traction). RESULTS: In 158 patients transvaginal bilateral oophorectomy was performed without laparoscopic assistance. In another 29 patients bilateral transvaginal oophorectomy was performed with laparoscopy-assisted vaginal hysterectomy, and prophylactic bilateral oophorectomy by the transvaginal route was successful in all but 1 of 143 patients with ovaries of grade I or higher. In 20 patients laparoscopic lysis of adhesions was necessary to permit transvaginal oophorectomy. Ninety-seven patients underwent transvaginal unilateral oophorectomy, 74 with conventional vaginal hysterectomy and 23 with laparoscopy-assisted vaginal hysterectomy. Among the patients not having oophorectomy, all ovaries had sufficient mobility to have been removed transvaginally. CONCLUSION: Good surgical practice dictates that visibility and accessibility be the primary criteria for selecting the route of oophorectomy with hysterectomy. In most patients the ovaries are visible and accessible to transvaginal removal. (Am J Obstet Gynecol 1996;175:1483-8.)     

The effect of aging on the subcellular distribution of estrogen receptor-alpha in the cholinergic neurons of transgenic and wild-type mice

The degeneration of the basal forebrain cholinergic system plays an important role in cognitive deterioration in aging and Alzheimer's disease. Brain cholinergic neurons and their projections are affected by changes in the circulating levels of estrogens, which exert their effects mainly through the estrogen receptors. In this study, we investigated the effect of aging, estrogen status and transgenic genotype on the number of cholinergic neurons and the estrogen receptor alpha (ERalpha) content in the medial septum-vertical limb of the diagonal band of Broca. We used 6- and 12-month-old female double transgenic mice carrying mutated human amyloid precursor protein (APPswe) and presenilin-1 (PS1-A246E), and their nontransgenic littermate controls, which had been sham-operated or ovariectomized at the age of 3 months. Brain sections were double immunostained for choline acetyltransferase (ChAT) and ERalpha and used for stereological cell counting. We found that the number of ChAT-immunoreactive (ir) neurons containing nuclear ERalpha-ir was significantly lower in 12- than in 6-month-old mice. However, the age of the mice, the transgenic genotype or ovariectomy had no effect on the total number of ChAT-ir neurons, or on the number and percentage of all ChAT-ir neurons that contained ERalpha. These results indicate that aging is associated with translocation of ERalphas from the nucleus to the cytoplasm. We propose that this phenomenon is linked to those age-related processes known to be involved in inhibiting ERalpha binding to nuclei.     

补肾宁心方对去卵巢兔动脉粥样硬化的保护作用

目的 研究补肾宁心方对去卵巢兔动脉粥样硬化形成的影响。方法 26只3月龄新西兰雌兔随机分为正常组、假手术组、对照组(卵巢切除)、中药组(卵巢切除并灌以补肾宁心方),除正常组外均于手术2周后给予高脂饮食,中药组同时灌胃给补肾宁心方中药,连续3个月。各组于第12周末测定血脂(TC、TG、LDL-C和HDL-C)以及一氧化氮(NO)水平;取主动脉行组织形态学观察以及在光镜和扫描电子显微镜下行病理学检查,利用图像分析仪计算动脉粥样硬化斑块内膜面积比和内膜中膜厚度比、面积比。结果 12周末除正常组外,各组动物血脂测定结果比较,差异无显著性。与对照组比较,中药组血清NO水平明显升高,主动脉硬化斑块面积与动脉内膜比值,内膜中膜厚度比、面积比均明显降低,主动脉病理变化减轻。结论 补肾宁心方可抑制去势雌兔动脉粥样硬化形成,对血管内皮细胞具有保护作用。