染料木素对去卵巢大鼠颌骨代谢的改善作用

目的 探讨染料木素对去势大鼠颌骨代谢及雌性生殖系统的作用。方法 切除成年雌性大鼠双侧卵巢，造成绝经后骨质疏松的动物模型。双能X线法检测颌骨、股骨骨密度，生化法检测血清碱性磷酸酶(alkaline phosphatase，ALP)、酸性磷酸酶(acid phosphatase，ACP)，放射免疫法检测骨代谢因子IL-1β、IL-6、转化生长因子α(tumor necrosis factor-α，TNF-α)、降钙素和骨钙素，探讨染料木素对去势大鼠颌骨代谢的作用；通过血清雌二醇含量和子宫重量的变化监测染料木素的雌激素样副作用。结果 去势大鼠骨密度显著减少；血清ALP、ACP和IL-1β、骨钙素显著高于非去势组。口服染料木素后，大鼠骨密度显著增加；血清ALP、ACP、骨钙素显著增高，其中ALP和骨钙素的增加显著优于雌激素组，IL-1β和TNF-α显著降低；大鼠子宫重量系数显著低于雌激素组。结论 染料木素能够通过抑制骨吸收和促进骨形成有效改善去势大鼠颌骨代谢，副作用弱于雌激素。染料木素在防治颌骨乃至全身骨质疏松方面具有开发前景。     

重组人生长激素对去势大鼠正畸牙牙周组织改建的影响

目的:探讨重组人生长激素(recombinanthumangrowthhormone,rh-GH)对去势(ovariectomy,OVX)大鼠正畸牙移动后牙周组织细胞变化的影响。方法:30只7周龄SPF级雌性Wistar大鼠随机分为3组:对照组、去势盐水组(OVX-NS组)和去势生长激素组(OVX-GH组)。将去势摘除双侧卵巢和腹部皮下注射rh-GH作为不同处理因素,观察第15天和第30天时3组大鼠正畸牙移动引起牙槽骨受压侧破骨细胞数的变化,并进行组织学观察。用SPSS12.0软件包对数据进行完全随机设计资料的方差分析。结果:对3组大鼠不同时间正畸牙牙槽骨受压侧破骨细胞计数进行比较,发现同一时间3组数据的差异有统计学意义(P<0.05);OVX-NS组比OVX-GH组显著增多(P<0.05),对照组最少;同组相比,第15天处死的大鼠与第30天处死的大鼠其破骨细胞数无显著差异(P>0.05);牙周组织学观察见,OVX-GH组牙周膜的损伤和创伤性炎症较OVX-NS组明显减轻。结论:去势(成年)大鼠腹部皮下注射rh-GH,能够减少其正畸牙移动引起的受压侧破骨细胞数目,同时可促进牙周组织因正畸力所致的病理性变化的恢复,对成年正畸治疗有良好的协同作用。     

Alcoholic and isocaloric diet,but not ovariectomy,influence the apoptosis of bone cells within the alveolar bone crest of rats

ObjectiveStudies suggest that chronic alcoholism as well as oestrogen deficiencies may affect bones in general, including alveolar bone and, by doing so, increase individuals’ susceptibility to develop progressive periodontal disease. This paper aims to verify the influence of chronic alcoholism and/or oestrogen deficiencies in the apoptosis of bone cells of the alveolar bone crest region in rats.DesignInitially, 54 rats were divided into ovariectomized (Ovx) and Sham operated (Sham) groups. Thirty days after surgery, these two groups were equally sub-divided, and received, for 56 days, the following dietary intervention: alcoholic diet (with 20% alcohol solution,), isocaloric diet and ad libitum diet (free diet). Analysis was undertaken by immunohistochemistry, using an antibody to detect apoptosis (anti PARP p-85).ResultsWhen comparing the six experimental groups, no significant differences were observed in the apoptosis of bone cells. Also, there was no significant difference in the quantity of cells undergoing apoptosis when the animals from Ovx groups were compared with those from Sham groups. However, when comparing only different dietary groups, differences were observed between the groups ad libitum and isocaloric, to osteoblasts (p = 0.045); and ad libitum and alcohol, to osteocytes (p = 0.007).ConclusionIt is concluded that ovariectomy was not able to influence the rate of apoptosis of bone cells of the alveolar bone crest region in rats and that a possible influence of diet on apoptosis of osteoblasts and osteocytes cannot be ruled out.     

The variation of cancellous bones at lumbar vertebra,femoral neck,mandibular angle and rib in ovariectomized sheep

This study aimed to compare the variation of cancellous bones at four skeletal sites: lumbar vertebra, femoral neck, mandibular angle and rib in ovariectomized sheep. Sixteen adult sheep were randomly divided into two groups: eight sheep were ovariectomized served as experimental group; the other eight untreated sheep were served as control group. Bone mineral density was assessed by dual-energy X-ray absorptiometry on lumbar vertebrae at baseline and twelve months after ovariectomy. After 12 months, lumbar vertebrae L3 and L4, femoral necks, mandibular angles and the fourth ribs were harvested for micro-CT scanning, histological analysis and biomechanical test. The results showed that bone mineral density of lumbar vertebra decreased significantly in twelfth month (p < 0.05). The results of micro-CT showed that the bone volume/total volume decreased by 45.6%, 36.1% 21.3% and 18.7% in lumbar vertebrae, femoral necks, mandibular angles and ribs in experimental group (p < 0.05) respectively. The trabecular number showed the same downtrend (p < 0.05). Histological analysis showed trabecular area/tissue area decreased by 32.1%, 23.2% and 20.7% in lumbar vertebrae, femoral necks and mandibular angles respectively (p < 0.05), but no significant difference in ribs. Specimens elastic modulus from lumbar vertebra, femoral neck and mandibular angle were 952 ± 76 MPa (628 ± 70 MPa), 961 ± 173 MPa (610 ± 72 MPa) and 595 ± 60 MPa (444 ± 31 MPa) in control group (experimental group) respectively. These datum indicated that the sensibility of cancellous bones to oestrogen deficiency in ovariectomized sheep was site-specific on a pattern as follows: lumbar vertebra, femoral neck, mandibular angle and rib.     

Bone mineral density and fractures after risk-reducing salpingo-oophorectomy in women at increased risk for breast and ovarian cancer

AimRisk-reducing salpingo-oophorectomy (RRSO) reduces ovarian cancer risk in BRCA mutation carriers. RRSO is assumed to decrease bone mineral density (BMD) and increase fracture risk more than natural menopause. We aimed to compare BMD and fracture incidence after premenopausal RRSO to general population data and identify risk factors for low BMD and fractures after RRSO.MethodsIn 212 women with RRSO at premenopausal age, BMD was measured by dual energy X-ray absorptiometry. Fractures and risk factors were assessed by self-administered questionnaire. Fracture incidence after RRSO was compared to general practitioner data by using standardised incidence ratios (SIRs). Risk factors for low standardised BMD-scores and fractures were identified by regression analyses.ResultsMedian age at RRSO was 42 years (range 35–65) and duration of follow-up 5 years (2–8). Standardised lumbar spine (Z = 0.01, p = 0.870) and femoral neck BMD (Z = 0.15, p = 0.019) were not lower than population BMD. Higher age at time of RRSO and use of hormonal replacement therapy were associated with higher, and current smoking with lower standardised BMD-scores. Sixteen women reported 22 fractures. Fracture incidence was not higher than expected from the general population (all fractures: 25–44 years: SIR 2.12 [95% confidence interval (CI) 0.85–4.37]; 45–64 years: SIR 1.65 [95% CI 0.92–2.72]).ConclusionFive years after RRSO, BMD and fracture incidence were not different than expected from the general population. Based on these data it appears safe not to intensively screen for osteoporosis within five years after RRSO, although prospective research on the long-term effects of RRSO on bone is warranted.     

Irreversible Changes in Rat Erythrocyte Na+ Transport Systems with Progesterone and Estradiol Administration

In order to test whether alterations in Na⁺ transport systems occurring in women when the hormonal status is disturbed such as in pregnancy, under contraceptive or estradiol therapy are a direct result of hormonal action on these transport systems, Na⁺, K⁺-pump Na⁺, K⁺ outward cotransport and passive Na⁺ permeability were measured in erythrocytes of ovariectomized rats receiving estradiol or progesterone. No significant changes in Na⁺, K⁺-pump were observed in either conditions. Conversely, progesterone was found to decrease Na⁺, K⁺-cotransport and estradiol to increase this system, whereas both steroids increased passive Na⁺ permeability.     

Raloxifene affects fatty acid oxidation in livers from ovariectomized rats by acting as a pro-oxidant agent

Estrogen deficiency accelerates the development of several disorders including visceral obesity and hepatic steatosis. The predisposing factors can be exacerbated by drugs that affect hepatic lipid metabolism. The aim of the present work was to determine if raloxifene, a selective estrogen receptor modulator (SERM) used extensively by postmenopausal women, affects hepatic fatty acid oxidation pathways. Fatty acids oxidation was measured in the livers, mitochondria and peroxisomes of ovariectomized (OVX) rats. Mitochondrial and peroxisomal β-oxidation was inhibited by raloxifene at a concentration range of 2.5–25 μM. In perfused livers, raloxifene reduced the ketogenesis from endogenous and exogenous fatty acids and increased the β-hydroxybutyrate/acetoacetate ratio. An increase in ¹⁴CO₂ production without a parallel increase in the oxygen consumption indicated that raloxifene caused a diversion of NADH from the mitochondrial respiratory chain to another oxidative reaction. It was found that raloxifene has a strong ability to react with H₂O₂ in the presence of peroxidase. It is likely that the generation of phenoxyl radical derivatives of raloxifene in intact livers led to the co-oxidation of NADH and a shift of the cellular redox state to an oxidised condition. This change can perturb other important liver metabolic processes dependent on cellular NADH/NAD⁺ ratio.     

Estrogen Deprivation and Myocardial Infarction: Role of Aerobic Exercise Training,Inflammation and Metabolomics

In general, postmenopausal women present higher mortality, and worse prognosis after myocardial infarction (MI) compared to men, due to estrogen deficiency. After MI, cardiovascular alterations occur such as the autonomic imbalance and the pro-inflammatory cytokines increase. In this sense, therapies that aim to minimize deleterious effects caused by myocardial ischemia are important. Aerobic training has been proposed as a promising intervention in the prevention of cardiovascular diseases. On the other hand, some studies have attempted to identify potential biomarkers for cardiovascular diseases or specifically for MI. For this purpose, metabolomics has been used as a tool in the discovery of cardiovascular biomarkers. Therefore, the objective of this work is to discuss the changes involved in ovariectomy, myocardial infarction, and aerobic training, with emphasis on inflammation and metabolism.     

雌激素水平对大鼠内皮功能的影响

目的:观察性激素对雌性大鼠血管内皮细胞(VEC)增殖的影响,比较成年雌性大鼠人工绝经前、后及补充不同剂量性激素后内皮功能的变化。方法:(1)以MTT法检测含不同浓度的17-β雌二醇(E2),孕酮(P)的培养基对细胞增殖的影响;(2)将48只成年SD雌性大鼠随机分为5组:假手术组、单纯去势组、去势+补充大剂量E组、去势+补充中剂量E组、去势+补充小剂量E组。观测各组血管壁一氧化氮合成酶(NOS)含量及血中一氧化氮(NO)、内皮素(ET)、前列环素(PGI2)、血栓烷A2(TXA2)的含量。结果:(1)3×10-8、3×10-7ME2可促进雌性大鼠VEC增殖,Tamoxifen可阻断E的这种作用;(2)与假手术组比较,单纯去势组大鼠血管壁NOs、血清NO含量降低;血浆ET含量、TXA2/PGI2比值增加(P<0.01)。与单纯去势组比较补充适量雌激素组或雌孕激素组可改善这一状况。结论:绝经后雌激素水平下降可引起内皮功能障碍,补充适量雌激素可改善这一状况。     

Estrogen Replacement Reduces Hearing Threshold Shifts and Cochlear Hair Cell Loss After Acoustic Overexposure in Ovariectomized Rats

Objectives.The relationship of estrogen (the primary female sex hormone) with hearing function has been studied in both humans and animals. However, whether estrogen levels affect hearing remains uncertain. Therefore, in this study, we investigated changes in the vulnerability of hearing to acoustic overexposure in ovariectomized female rats.Methods.Eighteen 8-week-old female Sprague-Dawley rats were separated into four groups as follows: sham ovariectomy (OP), OP only, and OP treated with low (10 µg/kg) or high doses (100 µg/kg) of estrogen. Rats in the estrogen replacement groups were given two intraperitoneal injections. Hearing thresholds were measured before noise exposure, and at 1 day and 2 weeks after exposure.Results.The hearing thresholds of the sham OP and OP-only groups were not significantly different. However, both estrogen groups showed a lower threshold shift than the OP-only group. Histological immunostaining analyses showed that hair cell loss in the 32 kHz region was more severe in the sham OP group than in the OP-only group. Furthermore, there was little or no hair cell loss in either estrogen replacement group and significantly more hair cell loss in the OP-only group.Conclusion.These results suggest that estrogen replacement may reduce the vulnerability of hearing to noise exposure in menopausal women.