高钙饮食对老年雌性大鼠皮质骨的影响

目的研究高钙饮食对老年雌性大鼠皮质骨的保健作用。方法按照食料中钙含量不同,大鼠随机分为3组,分别喂饲低钙饲料(0.1?)、中钙饲料(0.6?)、高钙饲料(1.2?),持续12w。采用pQCT技术测定股骨中段皮质骨相关参数。结果高钙组大鼠股骨中段皮质骨的骨密度和骨矿含量都明显升高。高钙饮食显著提高皮质骨面积及皮质骨厚度,而对股骨中段外周面积和内周面积没有明显影响。结论高钙饮食能够提高老年雌性大鼠皮质骨的骨量、面积和厚度,从而维护皮质骨的骨骼健康。     

双侧卵巢切除大鼠不同时间段骨形态计量学参数的观察

目的观察去卵巢大鼠骨质疏松模型复制情况并动态观察去卵巢后不同时间段骨丢失情况，为抗骨质疏松药物研究提供对照依据。方法4．5月龄SD雌性大鼠，按体重随机分组，大鼠摘除双侧卵巢；在实验的第0d（4．5月龄）、4w（5．5月龄）、12w（7、5月龄）、18w（9．5月龄）杀死大鼠取材；采用体内双荧光标记法，胫骨上段硬组织包埋切片及松质骨形态计量学分析处理，观察去卵巢后不同时间段骨丢失情况。结果大鼠去卵巢4w后骨量显著降低，骨结构变差，骨形成有增加，骨吸收增加，骨吸收大于骨形成，骨转换增加。去卵巢12w后，大鼠骨量进一步降低，骨小梁宽度先变窄（4w）后变宽（8、12、18w），骨形成和骨吸收均增加，去卵巢后大鼠在前一个月内（4w）骨量（Tb．Ar％）降低64．18％，差异有显著性（P〈0．05）。结论大鼠去卵巢4w后骨量降低，骨结构变差，骨形成和骨吸收增加，骨转换增加，去卵巢12w到18w骨量持续丢失，但较缓和，提示去卵巢后骨丢失在前4。最快更明显。因此，用于药物研究可选择去卵巢后4w时间进行。     

十一酸睾酮对老年雄性大鼠骨作用的形态计量学观察

目的运用形态计量学的方法，观察在动物体内雄激素（十一酸睾酮）对老年大鼠骨的作用，并探讨其作用机理。方法23月龄Wistar雄性大鼠20只，随机分为治疗组、空白对照组，每组10只；3月龄Wistar雄性大鼠10只为青年对照组；治疗组用药1个月后取材，并在取材前第13天、第3天行四环素标记，取左侧胫骨近段、第四腰椎在VIDAS图像分析系统下作骨组织形态计量学参数测定。结果与青年组比较，空白组大鼠骨小梁骨量减少，骨形成及骨吸收参数均降低，骨矿化降低，提示低转换型骨质疏松代谢模式的发生；与空白组比较，治疗组大鼠骨形成指标、骨吸收指标及骨矿化指标均有增加，其中骨形成大于骨吸收。结论雄激素能够促进骨形成及骨转换、增加骨量、改善骨结构、增加骨强度。     

中药复方护骨胶囊对糖皮质激素诱导骨质疏松 大鼠骨密度和骨形态计量学的研究

目的 探讨中药复方护骨胶囊(主要由制何首乌、淫羊藿、熟地黄等多味中药加工而成的复方制剂)对糖皮质激素诱导骨质疏松大鼠骨丢失的影响.方法 3月龄SPF级雄性SD大鼠30只,随机平均分为3组:正常对照组(Nrm)、激素组(Met)和中药组(CH).Met组:皮下注射甲强龙(Met)5mg/kg/d,每周5次;CH组:在Met组基础上给予中药复方护骨胶囊(150 mg/kg/d)灌胃,实验期12w.大鼠右侧股骨和腰椎行骨密度(BMD)测定,右侧胫骨行骨形态计量学分析.结果 Met组腰椎和股骨BMD显著低于Nrm组;CH组腰椎和股骨BMD显著高于Met组.Met组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著低于Nrm组,Tb.Sp、ES/BS显著高于Nrm组;中药组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著高于Met组,Tb.Sp,ES/BS显著低于Met组.结论 中药复方护骨胶囊在提高激素诱导骨质疏松大鼠的骨密度,促进骨形成,降低骨吸收,延缓骨丢失方面有积极作用,对继发性骨质疏松的预防和治疗有一定前景.     

中药复方护骨胶囊对糖皮质激素诱导骨质疏松大鼠骨密度和骨形态计量学的研究

目的 探讨中药复方护骨胶囊(主要由制何首乌、淫羊藿、熟地黄等多味中药加工而成的复方制剂)对糖皮质激素诱导骨质疏松大鼠骨丢失的影响。方法 3月龄SPF级雄性SD大鼠30只,随机平均分为3组：正常对照组(Nrm)、激素组(Met)和中药组(CH)。Met组：皮下注射甲强龙(Met)5 mg/kg/d,每周5次;CH组：在Met组基础上给予中药复方护骨胶囊(150mg/kg/d)灌胃,实验期12w。大鼠右侧股骨和L5行骨密度(BMD)测定,右侧胫骨行骨形态计量学分析。结果 Met组L5和股骨BMD显著低于Nrm组;CH组L5和股骨BMD显著高于Met组。Met组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著低于Nrm组,Tb.Sp、ES/BS显著高于Nrm组;中药组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著高于Met组,Tb.Sp,ES/BS显著低于Met组。结论 中药复方护骨胶囊在提高激素诱导骨质疏松大鼠的骨密度,促进骨形成,降低骨吸收,延缓骨丢失方面有积极作用,对继发性骨质疏松的预防和治疗有一定前景。     

老年大鼠松质骨骨重建的组织形态计量学研究

目的：研究老年大鼠及在促骨合成药前列腺素E2（PGE2）作用下松质骨骨重建和骨建造的形态计量学改变，探讨动物骨重建形态学新参数测量方法及其意义。方法：50只20月龄雄性Wistar大鼠随机分成5组，年龄对照组（基础组、10d和30d年龄对照组），PGE2给药组（分别10d和30d给予3mg/kg/d处理组）。用体内双荧光标记，不脱钙组织切片，粘合线（cement line）染色，骨组织形态计量学方法，测定骨重建和骨建造参数。结果：20月龄雄性大鼠胫骨近端松质骨的形成表面大多数为骨重建单位（占63．3％），少部分为骨建造单位（占26．7％）；PGE2用药后骨重建单位增加1．5倍，骨建造单位增加4倍，比值倒置，成骨细胞10d时明显增多。说明PGE2通过刺激成骨细胞骨合成而介民导骨建造性骨增加和骨重建性骨量增加，并以前为主。结论：老年雄性大鼠 松质骨以骨重建活动为主，仍有骨建造活动。PGE2主要通过刺激成骨细胞骨建造而增加骨量。     

骨形态计量学观察丹参骨宝对环磷酰胺大鼠胫骨上段的影响

目的用环磷酰胺造成大鼠的骨丢失，观察丹参骨宝的影响。方法用4．5mg·kg^-1·d^-1的环磷酰胺灌胃给大鼠，连续15d，造成大鼠骨丢失；用丹参骨宝进行预防给药。实验结束后，取大鼠左侧胫骨上段进行不脱钙包埋切片作骨组织形态计量学测量。同时观察大鼠胸腺、脾脏的重量指数，以及外周血白细胞数量。结果环磷酰胺可使大鼠外周血白细胞数量和脾脏指数明显下降，本实验剂量的丹参骨宝不能有效对抗这种免疫抑制。环磷酰胺通过明显抑制骨形成而导致骨量减少，骨显微结构退化等典型骨质疏松特征的出现。丹参骨宝能通过增加骨的沉积矿化率，促进成骨活性而增加环磷酰胺大鼠的骨量，改善骨微观结构。结论丹参骨宝可有效预防环磷酰胺所引起的大鼠骨丢失，其预防机制与促进骨的矿化沉积率，增加骨形成活性有关。     

低频脉冲电磁场对去势骨质疏松大鼠腰椎骨形态计量学的影响

目的观察低频脉冲电磁场(pulsed electromagnetic fields,PEMFs)对去势骨质疏松(osteoporosis,OP)大鼠腰椎骨组织形态计量学的影响,探讨PEMFs治疗OP的作用机制。方法将66只3月龄雌性SD大鼠随机分为假手术组(A组,n=12)、PEMFs实验组(B组,n=12)、雌激素对照组(C组,n=12)、卵巢切除对照组(D组,n=30)。A组大鼠仅切除卵巢周围部分脂肪组织,不切除卵巢;其余各组大鼠均切除双侧卵巢,制备去势OP大鼠模型。术后12周,B组采用低频PEMFs(8 Hz、3.8 mT、40 min/d)干预治疗30 d;C组采用倍美力0.065 mg/(kg.d)灌胃30 d;A、D组正常饲养。观察各组大鼠一般情况,术后12周检测血清雌二醇水平;干预治疗30 d后处死大鼠,取L4椎体作组织学切片,行静态骨形态计量学分析。结果术后D组大鼠毛发逐渐稀疏,活动迟缓,精神不振,反应较迟钝;A、B、C组大鼠毛发均光洁,精神及活动正常。术后12周,A组和D组大鼠血清雌二醇水平分别为(54.93±23.52)pg/mL和(31.99±23.45)pg/mL,比较差异有统计学意义(t=2.345,P=0.029)。干预治疗30 d后HE染色观察示,D组骨质变薄,骨髓扩大,骨小梁分布稀疏并变细,见断裂现象;A、B、C组骨小梁粗细一致,分布均匀,无断裂现象。B组大鼠L4椎体骨小梁面积百分比显著高于D组(P<0.05),也高于A、C组,但差异无统计学意义(P>0.05);骨小梁厚度显著高于D组(P<0.05),低于A、C组,但差异无统计学意义(P>0.05);骨小梁数量显著低于D组(P<0.05),高于A、C组,但差异无统计学意义(P>0.05);骨小梁分离度高于D组,低于A、C组,差异均无统计学意义(P>0.05)。结论 8 Hz、3.8 mT的PEMFs干预30 d可有效改善去势OP大鼠骨显微结构,增加骨小梁面积百分比、骨小梁厚度,降低骨小梁数量,对大鼠OP有良好的防治作用。     

骨形态计量学对增龄及去睾丸大鼠骨代谢的实验研究

目的 探讨３月半龄雄性大鼠增龄及去睾丸后骨量的变化,比较两之间骨代谢的变化。方法 ２０只３月半龄ＳＤ雄性大鼠,随机分成基础对照组、年龄对照组和去睾丸组,同等条件下饲养９０天。实验结束,取胫骨近端行不脱钙骨制片进行骨组织形态计量学分析。结果 年龄对照组（６月半龄）与基础对照组（３月半龄）相比,骨组织静态参数骨小梁面积百分率有下降趋势,骨的显微结构明显变差,动态参数如荧光标记周长百分率、骨形成率和单     

骨形态计量学观察睾酮对雄性去势大鼠松质骨的影响

目的 通过骨形态计量方法观察雄激素替代疗法对去睾丸致骨质疏松大鼠不同部位松质骨的影响。方法30只4月龄SD雄性火鼠，随机分成基础对照组（A组、实验开始时处死），年龄对照组（B组）、去睾丸组（C组）和去睾丸加睾丸酮组（D组），B组和C组每日生理盐水5ml／kg，D组每日甲基睾丸酮片1．8mg／kg，灌胃90d。实验结束，处死全部大鼠，取胫骨上段和第5腰椎进行不脱钙骨制片，用计算机全自动图象分析系统进行骨组织形态计量学分析。结果 大鼠去睾丸后胫骨上段骨量下降，骨形成和骨吸收都增加；腰椎骨量也下降，骨吸收也增加，但骨形成表现为降低。睾酮能阻止去睾丸后胫骨上段的骨量丢失（％Tb．Ar＋44．8％，P〈0．05），降低骨高转换；但不能完全阻止腰椎的骨量丢失，只能抑制骨吸收，对骨形成影响不大。结论 雄激素替代治疗能阻止雄激素水平下降造成的大鼠松质骨的骨量丢失，胫骨上段对雄激素的敏感性比腰椎部位的高。     

Effects of sodium fluoride,vitamin D,and calcium on cortical bone remodeling in osteoporotic patients

Summary The purpose of this histomorphometric study of iliac bone biopsies from 10 postmenopausal osteoporotic patients was to describe the effects of sodium fluoride (combined with calcium and vitamin D) on remodeling in cortical bone after 6 months and after 5 years of tretment. Biopsies had been fixed in absolute methanol, embedded undecalcified in methylmetacrylate, and cut on a heavy-duty microtome. The therapy had no effect on the thickness of cortical bone in the iliac crest but increased the porosity slightly. It had no statistically significant effect on depth of resorption or thickness of new walls formed at remodeling sites but treatment increased the fraction of osteons undergoing remodeling in cortical bone. After 6 months of treatment, the increase was due to an enhanced activation of new remodeling sites, but in biopsies taken after 5 years of treatment, some degree of mineralization defect was observed and the duration of the remodeling cycle appeared to be prolonged. The mechanism underlying this qualitative change in the response to treatment is unknown, and it is unclear whether the mineralization defect may be prevented by, e.g., an altered supplementation of vitamin D or calcium.     

Effect of vitamin K2 on lumbar vertebral bone: histomorphometric analyses in experimental osteoporotic rats

The in-vivo effect of vitamin K₂ on bone metabolism was investigated by histochemical and morphometric methods, using an animal model of osteoporosis. Eighteen female Wistar rats were divided into three groups. Rats in group A had sham ovariectomies, group B were ovariectomized, and group C were ovariectomized and received vitamin K₂, at 10 mg/kg per day, injected subcutanously. The lumbar vertebral bones were evaluated 8 weeks after the operation by a modified tetrachrome method after decalcification. Mineralized bone areas, osteoid, and deficectively mineralized bone areas in group B were markedly decreased compared with findings in group A, but these features in group C were not severely decreased. There was no significant difference in total bone areas and total bone volumes among the three groups. Accordingly, it appeared that vitamin K₂ had an effect in reducing mineralized bone loss after the ovariectomy. In conclusion, vitamin K₂ is thought to be beneficial for the properties of bone microarchitecture in the condition of osteoporosis. Received: September 14, 2000 / Accepted: June 11, 2001     

Bone histological heterogeneity in postmenopausal osteoporosis: A sequential histomorphometric study

We studied sequential bone biopsies performed at 6 to 24 month intervals from 14 untreated osteoporotic women (64 ± 7). Subgroups were defined, respectively, by increased osteoclastic resorption surfaces and decreased osteoblastic surfaces ± 2 S.D. Normal values were obtained from bone biopsy of 23 normal women (61 ± 8). When patients were divided into subgroups according to the above criteria the first biopsy showed that 3 out of the 14 patients had high resorption surfaces and 6 had low osteoblastic surfaces. Eight patients spontaneously changed during the study. In 2 patients there was a change in resorption surfaces, in 3 in osteoblastic surfaces and in 3 a change in both osteoblastic and resorption surfaces was observed. Considering the first or second bone biopsy results the patient variance was higher than the control subject's variance; however the variance between the first and second bone biopsy of one patient was not different from the variance inside the group of patients. The average intraindividual variation of the parameters on sequential biopsies was of the same order as the one we previously observed on simultaneous bone biopsies of normal and hemodialyzed patients. We concluded that if osteoporosis is a heterogeneous disorder, subgroups cannot be definitively defined on the basis of cellular parameters of bone remodelling assessed on bone biopsies.     

Effects of fluoride on cortical bone remodeling in the growing domestic pig

The purpose of the experiment was to assess the effects of fluoride (F⁻) on the remodeling process of cortical bone. Sixteen pigs, eight experimental animals receiving a supplement of 2 mg F⁻/kg b.w. and eight controls, were studied in individual sties from age 8 to 14 months. At slaughter samples of cortical bone were obtained from the right femur and embedded undecalcified. A new stereologic model based on fluorochrome tissue time markers and isotropic uniform random histologic sections was implied in order to obtain information in three-dimensional terms about dynamic aspects of remodeling.

The rate of remodeling was increased in cortical bone from pigs receiving F⁻ due to an increased activation of new remodeling. A doubling of the length density of resorptive and formative osteons was observed, although the change was statistically significant for the formative osteons only. An 11% decrease in depth of resorption and an 8% decrease in thickness of new bone formed led to a small decrease in the radius of Haversian canals in the fluorotic bone. The porosity of cortical bone was slightly but significantly increased. At formative sites the osteoid thickness and the mineralization rate were not significantly changed by F⁻. It was concluded that the observed changes cannot be explained by F⁻ induced changes in a single cell. Fluoride appears to affect all cells involved in remodeling by direct or indirect mechanisms.     

Effect of bisphosphonates on the increase in bone resorption induced by a low calcium diet

This study investigates whether bisphosphonate-treated rats are still able to adapt to low calcium supply through an increase in bone resorption assessed by measuring the urinary excretion of [³H]-tetracycline from chronically prelabeled rats. First it was shown that in this model, parathyroid hormone was responsible for the increase in bone resorption on the low calcium diet. In the second part, animals were treated with the three bisphosphonates—clodronate, alendronate, and ibandronate—given in two doses. Animals receiving a dose that already strongly inhibits bone resorption were still able to respond to a low calcium diet by increasing bone resorption, showing the potency of the latter as a stimulator of bone resorption. Higher doses were, however, able to blunt this response. As soon as the treatment was discontinued, this increase in bone resorption resumed with clodronate but not with alendronate or ibandronate.     

Incorporation of sodium fluoride into cortical bone does not impair the mechanical properties of the appendicular skeleton in rats

Summary Clinical studies on the use of sodium fluoride (NaF) in osteoporotic patients have demonstrated increased spinal bone mass without a reduction in vertebral fracture incidence, and a trend towards reduced appendicular bone mass with an increase in peripheral fracture incidence. As previous reports have suggested that NaF becomes incorporated into bone's crystal structure, possibly affecting bone strength, we sought to examine the relationship among bone fluoride content, bone mass, and skeletal fragility. Twenty-one-day-old female Sprague-Dawley rats were treated with four different doses of NaF. The tibiae were subjected to histomorphometric and biochemical analyses, and the femora were tested in torsion for the properties of strength, stiffness, energy storage capacity, and angular deformation. The results showed that over 50% of the skeleton in these rats was turned over in the presence of NaF. The four different doses resulted in a linear increase in bone F concentration and suggested excellent absorption and incorporation of this drug. No changes in histomorphometric indices of bone formation or turnover were found. Despite the large fraction of bone formed during NaF treatment, and the linear increase in bone fluoride content in relation to dose, there were no changes observed in any of the mechanical properties. These results suggest that, even extensive incorporation of fluoride into bone, in the absence of an effect on bone mass or remodeling, does not significantly alter its capacity to withstand mechanical loads.     

Negative effects of nicotine on bone-resorbing cytokines and bone histomorphometric parameters in male rats

The effects of nicotine administration on bone-resorbing cytokines, cotinine, and bone histomorphometric parameters were studied in 21 Sprague–Dawley male rats. Rats aged 3 months and weighing 250–300 g were divided into three groups. Group 1 was the baseline control (BC), which was killed without treatment. The other two groups were the control group (C) and the nicotine-treated group (N). The N group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection for 6 days/week for 4 months. The rats were injected intraperitoneally with calcein 20 mg/kg body weight at day 9 and day 2 before they were killed. ELISA test kits were used to measure the serum interleukin-1 (IL-1), interleukin-6 (IL-6), and cotinine (a metabolite of nicotine) levels at the beginning of the study and upon completion of the study. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis revealed that nicotine treatment for 4 months significantly increased the serum IL-1, IL-6, and cotinine levels as compared to pretreatment levels. In addition, the serum cotinine level was significantly higher in the N group than in the C group after 4 months treatment. Histomorphometric analysis showed that nicotine significantly decreased the trabecular bone volume (BV/TV), trabecular thickness (Tb.Th), double-labeled surface (dLS/BS), mineralizing surface (MS/BS), mineral appositional rate (MAR), and bone formation rate (BFR/BS), while causing an increase in the single-labeled surface (sLS/BS), osteoclast surface (Oc.S/BS), and eroded surface (ES/BS) as compared to the BC and C groups. In conclusion, treatment with nicotine 7 mg/kg for 4 months was detrimental to bone by causing an increase in the bone resorbing cytokines and cotinine levels. Nicotine also exerted negative effects on the dynamic trabecular histomorphometric parameters.