营养性骨质疏松动物模型的实验研究

用营养控制建立的大鼠骨质疏松模型更接近于营养疗法,比用激素手术因素造成骨质疏松具有现实意义,有助于探讨膳食不平衡引起的骨质疏松发病机理,同时也为预防和治疗骨质疏松药物筛选打下了基础。方法：三周龄Ｗｉｓｔａｒ大鼠按体重随机分为五组,每组８只,饲料配方参照ＡＯＡＣ方法。第一组为对照组（蛋白质含量１８％,钙含量１．０％;第二组为低蛋白低钙组（蛋白质８％,钙含量为０．０２５％）;第三组为低蛋白中钙组（蛋白质含量８％,钙含量１．０％）;第四组为高蛋白低钙组（蛋白质含量２７．０％,钙含量为０．０２５％）;第五组为高蛋白中钙组（蛋白质含量２７％,钙含量１．０％）其余全价饲料均一致。动物饲养２０周,记录其体重变化情况,实验结束后计算饲料效价。大鼠进行全身骨密度测定,ＳＰＥＣＴ骨显像,血清Ｃａ,Ｐ,Ｍｇ,ＡＫＰ,ＢＧＰ,Ｅ２测定,尿ＨＯＰ,Ｃａ测定,股骨骨密度,长度,体积,湿重,去脂干重,灰重,骨钙含量的测定。胫骨及第三腰椎的病理学检查。结果：低蛋白低钙,高蛋白低钙的两组动物的各项检测结果均和对照组差异有显著性,符合骨质疏松的表现,证实营养干预能成功地制备骨质疏松动物模型。本文结果也证实,骨质疏松是以骨量减少为特征、骨组织显?     

补钙对大鼠峰值骨量形成和预防骨质疏松的作用

目的 :　探讨补钙对峰值骨量的影响及对绝经后骨质疏松发生的预防作用。方法 :　选用雌性大鼠喂给不同钙含量的饲料至 1 0 mo龄 ,半数动物断头处死 ,取股骨进行相关检测 ,了解不同钙摄入量对骨峰值的影响。半数动物行卵巢切除术 ,喂饲 1 0 w后断头处死 ,取股骨进行有关检测 ,了解不同峰值骨量对骨质疏松的预防作用。结果 :　高钙摄入组峰值期大鼠股骨骨密度、骨重、骨长度、骨皮质厚度和股骨最大载荷、骨应变量等值均较低钙摄入组高 ;去卵巢后各组骨密度均降低 ,但高钙摄入量大鼠股骨骨密度比低钙摄入量大鼠的高。结论 :　钙摄入量的增加能有效提高峰值骨量 ,较高的峰值骨量能延缓骨质疏松的发生和降低骨折发生的危险性     

硫酸软骨素加钙对卵巢切除大鼠骨密度和骨钙含量的影响

目的探讨硫酸软骨素加钙对卵巢切除大鼠模型骨密度和骨钙含量的影响。方法选用卵巢切除大鼠所诱发的骨质疏松模型，给予硫酸软骨素加钙治疗，同时设假手术组及模型对照组。3个月后测定大鼠骨密度、骨钙含量。结果发现假手术组和高剂量组大鼠股骨骨密度和股骨钙含量显著高于阴性对照组（P〈0．05）。结论表明硫酸软骨素加钙能增加卵巢切除大鼠的骨密度，对雌激素缺乏所诱发的骨钙丢失具有抑制作用。     

一种有机镓化合物对大鼠骨镓,钙及磷含量的影响

目的 探讨接触有机镓对动物骨镓、骨钙和骨磷含量的影响。方法 采用亚急性和慢笥动物染毒实验,将不同剂量的有机镓灌胃,分别偿同时间后大鼠的一般状况及及死后股骨中镓、钙、磷的含量及钙／磷比值。结果 亚急性染毒各剂量组动物股骨中镓及磷含量与对照组判别显著（Ｐ〈０．０１）,而骨钙值只有１２ｍｇ／ｋｇ剂量组与对照组有显著差异。慢性染毒各剂量组骨镓、钙、磷均与对照组差别显著（Ｐ〈０．０５）。而实验组与对照组的骨     

自幼补钙增加雌性鼠峰值骨密度的研究

100只8周龄Wistar雄鼠分为5组分别喂饲不同含钙量饲料32周后,每组半数动物处死,剩余大鼠除假去势组外均作双侧卵巢切除,术后大鼠喂饲相同含钙量膳食10周后处死。处死大鼠作骨密度,骨矿含量,骨组织切片及血清有关指标检测。结果：高钙组峰值骨密度明显高于低钙组（P＜0．01）,去势10周后以低钙组骨密度最低（P＜0．05）,骨组织形态学显示骨峰值期高钙组骨皮质较低钙组厚,骨小梁多且粗大。结论：自幼补钙有利于形成较高的峰值骨密度,而较高的峰值骨密度可延缓去势后骨量的丢失,从而对骨质疏松的发生发展有一定防治作用。     

原发性骨质疏松与钙营养

随着社会人口的老龄化，骨质疏松已成为许多国家的一种常见病。骨质疏松的病因还不清楚，可能与营养，年龄，性激素，运动有关，目前尚无理想的治疗方法。故针对骨质疏松采取合理的预防措施，具有重要的意义。目前简单易行的预防措施主要从营养与运动两方面入手。本文主要从钙对骨矿含量，骨丢失，原发性骨质疏松骨折等方面的影响综述钙营养五原发性骨抟疏松的关系，并提出钙的推荐量，简介补充钙的形式和影响吸收的因素。     

原发性骨质疏松与钙营养

随着社会人口的老龄化，骨质疏松已成为许多国家的一种常见病。骨质疏松的病因还不清楚，可能与营养、年龄、性激素、运动有关，目前尚无理想的治疗方法，故针对骨质疏松采取合理的预防措施，具有重要的意义。目前简单易行的预防措施主要从营养与运动两方面入手。本文主要从钙对骨矿含量（ＢＭＣ），骨丢失（ＢｏｎｅＬｏｓｓ），原发性骨质疏松骨折等方面的影响综述钙营养与原发性骨质疏松的关系，并提出钙的推荐量，简介补充钙的形式和影响钙吸收的因素     

骨质增生与骨质疏松

科学研究已经证实,人体骨钙的含量随年龄增长而不断减少。进入中老年以后骨钙开始逐步丢失,当丢失到原骨钙含量的30％左右时骨质便变得疏松、脆弱与柔软,负载能力大大下降,常在摔跤等不很大的外力下发生骨折,这便是骨质疏松症,实际上也即成年人的佝偻病或骨软化症。绝经后的老年妇女因其雌激素水平骤减而使钙、磷代谢紊乱,骨钙丢失得更快、更严重,因此其骨质疏松的发病率也相对更高。     

补钙补不上瓶颈在哪里

人到中年,骨钙便逐渐开始丢失。尤其是女性进入更年期及绝经期后,骨钙丢失进一步加速,女性65岁以后可能丢失骨钙达30％～50％,男性丢失的骨钙也在30％左右。缺钙的结果使骨密度下降,骨质疏松、动脉硬化等疾病接踵而来。对于老年人来说．补钙是保持健康生活的重要元素。而生活中有些老年人连续补充钙剂好多年,可在医院检查骨密度后,医生仍诊断为骨密度低下,严重的甚至患有骨质疏松症。因此很多人认为,人老了补钙也没用。     

水解牡蛎钙在大鼠体内的代谢和利用

为了解水解牡蛎钙的生物利用率，作者以含钙量相等（４５ｍｇ／ｄ）的水解牡蛎钙、碳酸钙、氯化钙喂饲缺钙动物模型大鼠４周，采用原子吸收法和ＥＤＴＡ络合滴定法测定了大鼠的血钙、尿钙、粪钙和骨钙，骨密度仪测定骨密度。结果表明，水解牡蛎钙组大鼠的钙吸收率和存留率分别为６７．３％±１６．７％和６４．６％±１７．５％，股骨骨钙含量为１３１．２±１．４８ｍｇ／ｇ，股骨骨密度（ＢＭＣ／ＢＷ）为０．３１８±０．０３４ｇ／ｃｍ２，均显著高于碳酸钙对照组。三组大鼠的血钙含量、体重增重和摄食量差异无显著性。提示水解牡蛎钙比常用钙剂碳酸钙更有利于机体的吸收和利用。     

Bone composition and histological analysis of young and aged rats fed diets of varied calcium bioavailability.

The effects of varied calcium bioavailability on bone development (young animal) and bone maintenance (aged animal) were evaluated by the application of bone composition and histologic/histomorphometric techniques.

Groups of male young (3-4 weeks old) and aged (24-month-old) rats were fed nutritionally-complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach or nonfat dry milk (NFDM). A 0.5% calcium casein-based diet group was included as a comparison at the National Research Council's requirement level. All animals were pair-fed to the spinach-fed group. At the end of 60 days, lumbar vertebrae, tibia and femurs were harvested for bone histomorphometric and bone composition analyses.

Histological analysis of the fifth lumbar vertebral body of the young spinach-fed group showed retarded development and mineralization of trabecular bone. Histomorphometry revealed that the spinach-fed group seemed to respond to the lower bioavailable calcium source by reducing the mineralization of bone matrix and stimulating bone resorption with a resultant decrease in bone volume (0.027, 0.059, 0.068 mm3 in spinach, NFDM and 0.5% calcium casein-based diet groups, respectively). The aged animals, however, appeared to respond to the reduction in available dietary calcium by mobilizing skeletal reserves, with a subsequent decrease in bone volume (0.057, 0.060, 0.073 mm3 in spinach, NFDM and 0.5% calcium casein-based diet groups, respectively).

This study demonstrates that a low bioavailable calcium source, spinach, suppresses calcium deposition in bones of young animals resulting in a reduction in both quality and quantity of bone. Moreover, despite the stable structure of the mature bone, a low bioavailable calcium source may also compromise the skeletal integrity of the aged animal.     

Effect of calcium citrate-malate on skeletal development in young, growing rats

It has been previously demonstrated that calcium from calcium citrate-malate (CCM), a mixture of calcium, citric acid and malic acid, is better-absorbed than calcium from calcium carbonate (CaCO3) in humans and in rats. It was of interest to determine if this differential in absorption would result in differences in bone development under chronic feeding conditions. The present study was designed to compare CCM with CaCO3 for effects on bone development in weanling female C/D rats fed either CCM or CaCO3 at 0.3 or 0.6% dietary Ca for 4 or 12 wk. There was a nonsignificant trend for rats fed CCM to weigh more and have larger bones than rats fed CaCO3. Histologic evaluation of cortical and trabecular bone revealed normal bone formation in all rats. Trabecular bone was significantly affected by calcium level and source. The 0.3% Ca diets (either source) resulted in reduced trabecular bone volumes in tibias. After 4 wk, rats fed CCM had 23-25% more trabecular bone than rats fed CaCO3. By 12 wk, the difference was even greater; rats fed CCM had 44-47% more trabecular bone than rats fed CaCO3. Dietary calcium source did not affect cortical bone. It is concluded that because of its positive effects on bone, CCM is a more bioavailable calcium source than CaCO3.     

Effects of NaCl on calcium balance, parathyroid function and hydroxyproline excretion in prednisolone-treated rats consuming low calcium diet

The short-term effects of dietary sodium chloride supplementation on calcium balance were examined in an animal model of corticosteroid-mediated osteoporosis. Changes in calcium and phosphate balance, parathyroid function and bone resorption elicited by salt supplements alone (8 g/100 g diet), prednisolone alone (2.2 mg/kg body wt per day) and both salt and prednisolone in combination were measured in rats consuming a low calcium diet (0.1% calcium) for 10 d. Parathyroid function was monitored by measuring urinary cyclic AMP excretion. Bone resorption was monitored by measuring urinary hydroxyproline excretion. Salt alone raised urinary calcium, cyclic AMP and hydroxyproline; prednisolone alone depressed net calcium absorption and urinary hydroxyproline but had no effect on urinary calcium. Salt and prednisolone each depressed calcium retention independently and together produced an additive adverse effect on calcium balance. Thus high dietary salt intakes augment urinary calcium loss, raise parathyroid activity, increase bone resorption and adversely affect calcium balance in prednisolone-treated growing rats with a restricted dietary calcium intake. These findings support the view that high salt intakes may exaggerate bone loss during chronic glucocorticoid therapy. Because people also develop osteoporosis during glucocorticoid therapy and respond to dietary salt supplements by increasing urinary calcium excretion and parathyroid hormone, high salt intakes may accelerate bone loss in patients receiving chronic glucocorticoid therapy. The beneficial effects of dietary salt restriction on the conservation of bone mass warrant investigation in these patients.     

EDTA滴定法测定保健食品中钙元素的改进研究

目的:使用改进的EDTA滴定法测定保健食品中的钙元素。方法:采用干法消化样品,以硫化钠做掩蔽剂,进行EDTA滴定测定。结果:方法相对标准偏差为0.024%～0.29%,加标回收率为94.7%～98.8%,经t检验,与ICP-AES法测定结果无显著性差异。结论:改进的EDTA滴定法结果准确,操作简单安全,能够用来测定保健食品中的钙元素。     

混合酸消解-EDTA滴定法测定头发中钙

目的建立EDTA滴定法测定头发中钙的方法。方法采用混合酸将头发消解后用去离子水定容,用EDTA标准滴定溶液滴定。结果滴定法测定头发中钙相对标准偏差为1.32%～2.61%,回收率为88.80%～110.40%。结论 EDTA滴定法测定头发中钙简便,精密度和准确度高,可作为测定头发中钙的方法。     

增加骨密度类保健食品功能评价方案联合应用的探讨

[目的]合理评价功效成分和补钙成分联合配方保健食品对实验动物增加骨密度功能的影响。[方法]参照《保健食品检验与评价技术规范》（2003版）“增加骨密度功能检验方法”,采用骨密度方案二试验联合钙吸收实验对某保健品进行评价。根据受试物的推荐剂量,设低、中、高三个剂量（0．17、0．33、1．00g／kg）组;在骨密度方案二试验中,,同时设立四个对照组：假手术对照组、去势模型对照组、雌二醇阳性对照组（1．0mg／kg的雌二醇）、碳酸钙对照组,对成年SD雌性大鼠行去势手术后进行试验;在钙吸收实验中,同时设立一个低钙对照组和一个碳酸钙对照组,对断乳SD大鼠进行试验。[结果]骨密度功能检测结果显示：1．00g／kg剂量组去势大鼠的体重增重明显低于模型对照组（P〈0．05）;且该组大鼠股骨远心端和中点骨密度、股骨骨钙含量均明显高于模型对照组（P〈0．05）。钙吸收实验显示：1．00g／ks剂量组大鼠的’体重、身长和表观吸收率均明显大干低钙对照组（P〈0．05）;但该组的这些指标与含钙量相同的碳酸钙对照组相比,差异无统计学意义（P〉0．05）。[结论]通过骨密度试验联合钙吸收实验,认为该保健食品既对去势大鼠有增加骨密度作用,又有补钙作用;联合方法可更全面评价该保健食品的增加骨密度功能。     

A simple ashing method for determination of Mg and Ca in laboratory animal feed and tissues

A simple procedure has been developed for preparation of animal tissues and diet mixtures for Mg and Ca analysis by atomic absorption spectroscopy. This procedure involves wet ashing in warm 30% hydrogen peroxide and extraction of metals, from the dried ash, into cold, dilute nitric acid. Less than 200 mg of tissue or feed are required. Measurements obtained by this method for hamster and rat myocardium give values similar to those found previously by more cumbersome methods. Concentrations of Mg and Ca in hamster serum, bone, kidney, and liver are also reported. Recovery of magnesium from bone and heart tissue was 101% and 102%, respectively. For calcium the respective values were 99% and 98%. This procedure is simple to carry out, does not generate corrosive fumes or require expensive equipment. It can be conveniently used to prepare large numbers of samples for atomic absorption spectrophotometry.     

某些食物中钙的原子吸收法测定

本文介绍了一种操作简便、结果可靠、钙含量可测范围宽(0.5—200ppm)的火焰原子吸收测定法。无论测定低浓度或高浓度钙,除应将燃烧器作90°水平转动外,仪器的其它操作条件都可保持不变。硅酸根、磷酸根和铝对钙的测定有严重干扰,加一定量锶盐作释放剂,效果极为满意。本方法的回收率在测低浓度钙时为95—105％,变异系数(相对标准偏差)<2％;测高浓度钙时为85—98％,变异系数<0.5％。本法测得结果与络合滴定法以及发射光谱法符合程度较好。曾用本法测定过蚕豆、雏鸡、蛋品等食物样品共三百多份,结果均较满意。     

Randomised Controlled Trial of Nutritional Supplement on Bone Turnover Markers in Indian Premenopausal Women

Young Indian women may be at risk of poor bone health due to malnutrition. The aim of this study was to examine the effects on bone metabolism of a nutritional supplement in women aged 25 to 44. The nutritional supplement was a protein-rich beverage powder fortified with multi-micronutrients including calcium (600 mg), vitamin D (400 IU), and vitamin K (55 mcg) per daily serving, while a placebo supplement was low-protein non-fortified isocaloric beverage powder. This 6-month randomised, controlled trial showed favorable changes in bone turnover markers (decreased) and calcium homeostasis; such changes in older adults have been associated with slowing of bone loss and reduced fracture risk. For example, serum CTX decreased by about 30% and PINP by about 20% as a result of the increase in calcium intake. There were also changes in the ratio of carboxylated to undercarboxylated osteocalcin and such changes have been linked to a slowing of bone loss in older subjects. For example, the ratio increased by about 60% after 3 months as a result in the improvement in vitamin K status. Finally, there were improvements in the status of B vitamins, and such changes have been associated with reductions in homocysteine, but it is uncertain whether this would affect fracture risk. The product was generally well tolerated. This study shows the nutritional supplement holds promise for improved bone health among young Indian women.     

不同类型燃煤型氟骨症的动物模型复制

目的：复制不同类型燃煤型氟骨症动物模型.方法：以SD大鼠为研究对象,按体重均衡随机分为五组（组内雌雄各半）;高氟组、高氟偏食组、低氟组、低氟偏食组、对照组.以氟病区煤烘玉米为主要饲料,复制氟骨症动物模型.以股动脉放血法处死动物,查看氟斑牙、测定尿氟、牙氟、骨氟、骨密度（BMD）.对其胫骨干骺端进行常规组织切片,HE染色观察组织学改变.结果：高氟、低氟组大鼠骨密度增高,与对照组比较差异具有统计学意义（P＜0.05）,胫骨病理显示成骨活跃.高氟、低氟偏食组大鼠骨密度降低,其中,高氟偏食组与对照组比较差异具有统计学意义（P＜0.05）,胫骨病理显示高氟偏食组大鼠密质骨呈骨软化,低氟偏食组呈轻度疏松化.结论：过量氟造成氟骨症大鼠成骨与破骨活动均增强的高骨转换状态,低钙偏食可使氟骨症破骨性骨吸收增强.