Effects of vitamin K(2) on bone of ovariectomized rats and on a rat osteoblastic cell line

The effects of vitamin K(2) on bone mineral density (BMD) and bone metabolic markers of ovariectomized rats, and those on mRNA expression of osteocalcin and IL-6 on a rat osteoblastic cell line, were investigated. BMD and bone metabolic markers were examined in ovariectomized rats after 2 months' treatment with vitamin K(2), and mRNA expression of osteocalcin and IL-6 were measured in the cell line after 24-hour treatment with vitamin K(2). Vitamin K(2) attenuated the decline in BMD after ovariectomy in the rats, and suppressed serum deoxypyridinoline levels of the ovariectomized rats. No effect on osteocalcin and IL-6 mRNA expression on the cell line was observed. In conclusion, vitamin K(2) has a bone-protective effect on ovariectomized rats.     

雷洛昔芬对去卵巢大鼠骨密度及血E2、IL-6水平影响的研究

目的观察雷洛昔芬对去势大鼠骨密度、血清E2、IL-6及子宫内膜的影响，探讨雷洛昔芬抗骨质疏松的作用机制。方法48只3个月龄雌性SD大鼠，随机分为SHAM组（假手术），0VX组（单纯去势），0VX＋E2组（去势＋雌激素），0VX＋R组（去势＋雷洛昔芬），每组12只。3个月后处死采集血，用放射免疫分析法检测并比较各组E2及IL-6的表达，取子宫内膜用HE染色法观察各组子宫内膜的形态变化并对子宫内膜腺体数目进行统计学分析。结果雷洛昔芬组大鼠骨密度显著高于去卵巢组（P＜0．05），血清IL-6浓度值显著降低，雌激素浓度的改变差异无统计学意义（与去卵巢组比较P＞0．05），对子宫内膜无明显影响（P＞0．05）。结论雷洛昔芬治疗骨质疏松的作用与血清中IL-6水平降低相关，与雌激素无显著相关，对子宫内膜无显著影响。     

替勃龙上调卵巢切除大鼠腰椎护骨素mRNA的表达

目的:建立绝经后骨质疏松(postmenopausalosteoporosis,PMOP)的大鼠模型,研究替勃龙对卵巢切除大鼠腰椎组织中护骨素(OPG)基因mRNA表达水平的影响,探讨其预防和治疗PMOP的作用机制。方法:6月龄未交配健康雌性SD大鼠40只,随机分为SHAM组,OVX组,OVX+戊酸雌二醇(E2)组和OVX+替勃龙(tibolone,TIB)组。灌胃13周后处死动物,第四腰椎行骨组织形态计量指标测定,第二腰椎采用RT-PCR方法,对OPGmRNA表达水平进行检测。结果:OVX组大鼠较SHAM组TBV%显著下降;OSV%明显升高(P<0·05);E2和TIB均可使OVX大鼠的TBV%明显升高,OSV%明显下降;OPGmRNA表达水平在OVX大鼠组织中下调,与SHAM组相比有显著性差异(P<0.05),E2和TIB均可上调OVX大鼠骨组织OPGmRNA表达水平(P<0.05)。结论:E2和TIB均通过抑制骨转换预防和治疗PMOP;PMOP的发生与OPG有关,TIB和E2一样,其抗骨吸收效应很可能是通过OPG介导的。     

雌激素、三苯氧胺与氟化物配伍预防去势大鼠骨丢失的研究

目的　比较三苯氧胺与雌激素对骨代谢的影响 ,及两者与氟化物配伍后是否产生协同效果。方法　将 142只 6月龄雌性SD大鼠行去势手术或假手术后随机分为 7组 (每组 19～ 2 1只 ) :(1)假手术组 ;(2 )去势组 ;(3)雌激素组 ;(4 )氟化物组 ;(5 )雌激素 +氟化物组 ;(6 )三苯氧胺组 ;(7)三苯氧胺 +氟化物组。治疗 12个月 ,行骨密度、腰椎骨组织形态计量学参数 (不脱钙骨切片 )、右股骨中段三点弯曲试验观察 ,并行子宫病理及血脂检查。结果　 (1)术后 12个月时 ,全身骨密度去势组为2 79mg/cm2 、治疗组为 2 86～ 2 98mg/cm2 ,腰椎骨密度分别为 2 32mg/cm2 、2 5 1～ 2 6 6mg/cm2 (P均<0 0 5 ) ;股骨中段骨密度 ,雌激素组 2 16mg/cm2 ,明显高于三苯氧胺组 195mg/cm2 (P <0 0 5 ) ;配伍治疗组与单药治疗组无明显差异 (P >0 0 5 )。 (2 )术后 4个月 ,两个配伍治疗组最大载荷 (均为 145牛顿 )与去势组 [(118± 2 4)牛顿 ]有显著差异 (P <0 0 5 ) ;术后 12个月各治疗组最大载荷为 132～ 15 5牛顿 ,均明显高于去势组 (10 8± 13)牛顿 (P <0 0 5 ) ,雌激素组最大载荷、弹性载荷均明显高于三苯氧胺组 (P <0 0 5 )。 (3)各组骨组织形态计量学检查未发现骨矿化不良现象。结论　雌激素在维持骨量、骨强度方面优于三苯     

雌激素对去卵巢大鼠骨丢失的骨形态计量学及组织学的影响

OBJECTIVES: To demonstrate the histomorphometric and histological changes of bone 3 weeks after bilateral ovariectomy in rats and to investigate the impacts of 4 different hormone replacement therapies on the bone histomorphometric, histological appearances. METHODS: Bilateral ovariectomies were done on 41 female rats and sham operations on other 9 (sham group) respectively. After 3 weeks, 4 different treatments: i.e. Livial, Gevrine, Premarin, Weinian were initiated separately on each 8 ovariectomized rats for another 3 weeks. The remaining 9 were served as controls (OVX group). All rats were sacrificed either 3 weeks after ovariectomy/sham operation or at the end of hormone therapies. Their femoral bone mineral density (BMD) were measured by dual energy X-ray absorptiometry (DEXA). Specimens of proximal femur were embedded undecacifide for histomorphometric analysis and of distal femoral metaphysics were procured for scanning electron microscope (SEM) and pathologic examinations. RESULTS: (1) Three weeks after OVX, the femoral BMD, mean cortical thickness decreased significantly while the number of osteoclast increased significantly as compared with sham group. The trabecular became thinner and irregular which changed the bone microstructure in three dimension. (2) After treatment of 4 different preparations, the above parameters restored to various extents to the sham operation levels. Among them, there was greater increase of femoral BMD on the Livial and Gevrine group as compared with Premarin and Weinian group (P < 0.05). CONCLUSIONS: Bilateral ovariectomy induced increased osteoclast activity and bone turnover, therefore caused accelerated bone loss. Treatment with combined sex hormones preparation could inhibit bone absorption and stimulate bone formation, especially those containing androgenic activity could increase the BMD.     

Effects of strontium ranelate,raloxifene and misoprostol on bone mineral density in ovariectomized rats

Objectives

To investigate the effects of strontium ranelate, raloxifene and misoprostol on bone mineral density (BMD) in ovariectomized rats to contribute to the individualization of the treatment of postmenopausal osteoporosis.

Study design

Sixty sexually mature female Sprague–Dawley rats weighing 250 g were used. The 60 rats were divided into six groups of 10 rats each: SR, MISO, RAL, SHAM, DW and OVX. All except the SHAM rats were subjected to bilateral ovariectomy. Three days after surgery, rats were administered strontium ranelate (Protelos^®, 2 g, Servier, Istanbul), 1800 mg/kg/day; misoprostol (Cytotec^®, 200 mcg, Ali Raif, Istanbul), 200 mcg/kg/day; raloxifene (Evista^®, 60 mg, Lily and Company, Istanbul), 3 mg/kg/day and 1 cc of distilled water by gavage for 8 weeks. Bone mineral density measurements were then performed.

Results

The strontium ranelate (SR) group had significantly higher vertebral BMD than all other groups. Femoral density in the SR group was also significantly higher than in other groups and there was no difference between femoral density in the strontium ranelate and sham groups.

Conclusions

Strontium ranelate, raloxifene and misoprostol can prevent bone loss in the vertebrae, whereas strontium ranelate can also prevent bone loss in the femur of ovariectomized rats. Strontium ranelate increases greater than raloxifene and misoprostol BMD in the vertebrae.

Condensation

Strontium ranelate may increase both vertebral and femur BMD in ovariectomized rats while raloxifene and misoprostol may only increase lumbar spine BMD.     

Luteal phase support using either Crinone 8% or Utrogest: results of a prospective,randomized study

OBJECTIVE: After tubal ligation, normal bone mass in the presence of gonadal deficit has been reported. These incongruent results motivated us to examine the topic. STUDY DESIGN: Bone mass was assessed by densitometry and ultrasonography 60 days after surgery on 100-day-old female Wistar rats. Fifteen Wistar rats with uterine horn ligation (TL) were compared with 15 unoperated, 15 with a sham uterine horn ligation (Sham-TL), and 15 ovariectomized (OVX), using ANOVA and a correlation test to determine the relations between results. RESULTS: Femoral and vertebral bone mass were significantly lower in the OVX y TL groups than in unoperated and controls groups (P<0.0001). CONCLUSIONS: Our study revealed significantly lower axial and peripheral bone mass in rats with uterine horn ligation.     

去卵巢山羊腰椎骨计量学指标的变化

目的　探讨用山羊制作绝经后骨质疏松动物模型的可行性。方法　切除山羊的双侧卵巢 (OVX) ,制备腰椎不脱钙骨切片 ,应用骨组织形态计量学方法 ,观察正常对照组 (3只 ,无手术处理 )、假手术组 (3只 ,开腹后缝合切口 )、OVX术后 6个月组 (4只 )、术后 18个月组 (5只 )腰椎骨计量学指标的变化。结果　OVX术后 6、18个月组的骨小梁体积占全部骨组织体积的百分比 [(7 9± 1 7)与 (5 8± 0 7) % ]、骨小梁体积占海绵骨体积的百分比 [(12 7± 1 8)与 (9 9± 0 6 ) % ]、平均骨小梁板密度 [(1 0± 0 2 )与 (1 1± 1 1)个 /mm]显著减少 (P <0 0 1) ;平均骨小梁板厚度 [(12 9± 4 5 )与 (95± 15 ) μm]也显著减少 (P <0 0 5 ) ;骨小梁表面和体积之比 [(16 6± 4 6 )与 (2 1 4± 3 1)mm2 /mm3 ]与平均骨小梁板间隙 [(10 0 4± 2 33)与 (95 3± 10 3) μm]则显著增加 (P <0 0 1) ;四环素单标记、双标记、1/ 2单标记与双标记表面之和占全部骨小梁表面的百分比 [(19 5± 3 8)与 (17 5± 1 0 ) %、(16 4± 3 3)与 (13 9± 2 5 ) %、(2 6 2± 5 1)与 (2 2 7± 2 9) % ],平均类骨质宽度 [(11 6± 1 1)与(12 0± 1 0 ) μm]、骨矿化延迟时间 [(2 3 6± 8 2 )与 (2 3 0± 6 1)d]、组织水平的骨形成速率     

四环素-雌酮和雌酮作用去势大鼠的骨形态计量学对照研究

目的比较四环素－雌酮和雌酮对卵巢切除（ＯＶＸ）大鼠股骨远端骨干骨形态参数的影响。方法２０只雌性大鼠随机分成４组,每组５只：四环素－雌酮治疗组、雌酮治疗组、ＯＶＸ组和假手术组,建立ＯＶＸ大鼠骨质疏松动物模型,药物喂养１３周后处死,用骨形态计量学方法研究四环素－雌酮和雌酮对骨形态和动力学参数的影响。结果与假手术组相比,四环素－雌酮组和雌酮组骨小梁的连接性均明显地高于假手术组（Ｐ＜０．０５）。与ＯＶＸ组相比,四环素－雌酮和雌酮组四环素标记表面和类骨质表面均明显增加,四环素－雌酮组的结果又明显高于雌酮组,更明显高于其它两组（Ｐ＜０．０５）。结论四环素－雌酮和雌酮可以明显地加强骨小梁的连接性,四环素－雌酮提高骨激活频率的作用优于雌酮。     

The effect of prolactin itself and in combination with estrogen on bone mineral density in female rats

Abstract

Estrogen deficiency induced by hyperprolactinemia can reduce bone mineral density. Hyperprolactinemia through other mechanisms other than estrogen deficiency, with direct effect on the bone might cause bone loss in women. The present study evaluated the effect of prolactin itself and in combination with estrogen on bone mineral density of female rats. This study was performed on 50 adult female rats divided into five groups; included (a) Sham, (b) Ovariectomized rats; and (c–e) included ovariectomized rats were given prolactin alone, prolactin?+?estradiol and estradiol, respectively. Bone mineral density (BMD) and vitamin D metabolism parameters were checked in all groups before and after the study. There was no significant difference in baseline values of these parameters. Estradiol could increase 1,25(OH)2D3 and PTH levels and decrease serum ALP level. In addition, Prolactin could increase serum 1,25(OH)2D3 and ALP levels and decrease tibia BMD significantly without any change in PTH level. Combination of estradiol and prolactin could increase serum 1,25(OH)2D3 and PTH and tibia BMD compared with OVX group. Combination of estradiol and prolactin could significantly increase tibia BMD, in ovariectomized rats. We hypothesized that this combination could improve bone loss secondary to hyperprolactinemia by elevated PTH.