旋转磁场作用对大鼠骨钙代谢的影响(英文)

Effect of rotating magnetic field on bone calcium metabolism in rat

背景:已有研究证明旋转磁场干预能使大鼠骨密度显著增加,并且能维持相当长的一段时间而不下降,且与性激素无关。目的:研究旋转磁场对大鼠骨钙含量的影响,以及与血清骨碱性磷酸酶(bone-specific alkaline phosphatase,BAP)和尿脱氧吡啶交联(deoxypyridinoline crosslinks,DPD)的相关性。设计:以实验动物为对象的随机对照实验。单位:一所大学生命科学院。材料:实验于2004-03/10在深圳市微生物基因工程重点实验室完成。健康成年SD大鼠90只,雌性60只,体质量(259±70)g,雄性30只,体质量(351±104)g。按雌雄随机分9组,雌性假手术组、去卵巢常钙对照组、去卵巢低钙对照组,去卵巢低钙实验组、去卵巢常钙实验组、去卵巢低钙中药实验组、雄性对照组、雄性低钙实验组、雄性常钙实验组,每组10只。干预:雌性大鼠除假手术组以外均切除卵巢,去卵巢对照组单纯去卵巢,去卵巢实验组手术15d体内残存雌激素代谢尽后,开始旋转磁场处理15d,1次/d,2h/次。雄性大鼠除对照组外均行磁场处理15d,1次/d,2h/次。分别给予常钙(含钙0.26%的食物)、低钙(含钙0.1%的食物)和辅以中药(补骨脂、黄芪、淫羊藿、肉苁蓉免煎粉剂等)饲料饲养。旋转磁场处理后,继续饲养15d,处死后取其股骨测量各组大鼠骨钙含量,取血清测量BAP含量,取尿液测DPD含量。主要观察指标:各组大鼠骨钙含量及血清BAP和DPD变化。结果:纳入90只大鼠,实验过程中死亡4只,进入结果分析86只。①经旋转磁场处理后大鼠骨钙含量增高:去卵巢低钙中药实验组及去卵巢低钙对照组分别为(0.226±0.015),(0.206±0.015)g/g,两组比较t=4.63,P<0.05;雄性常钙实验组及雄性对照组分别为(0.206±0.031),(0.199±0.014)g/g,两组比较t=4.21,P<0.05。②经旋转磁场处理后大鼠血中BAP含量增高:去卵巢常钙实验组及去卵巢常钙对照组分别为(20.52±1.78),(15.68±3.68)U/L,两组比较t=4.76,P<0.05;雄性低钙实验组及雄性对照组分别为(17.69±3.78),(8.53±2.54)U/L,两组比较t=4.59,P<0.05。③经旋转磁场处理后实验组大鼠尿中DPD下降:去卵巢低钙中药实验组及去卵巢低钙对照组分别为(86.97±37.19),(401.57±79.34)nmol/L,两组比较t=7.45,P<0.01;雄性常钙实验组及雄性对照组分别为(97.87±31.97),(168.71±53.19)nmol/L,两组比较t=8.31,P<0.01。结论:磁场能够在短时间内(15d)有效的促进大鼠的骨钙含量增加,且增加与血BAP升高及尿DPD下降成正相关。

BACKGROUND:Studies have proved that rotating magnetic field(RMF) can significantly increase bone mineral density(BMD) in rats,and such high BMD maintains for a long time which is independent of the actions of hormone.OBJECTIVE:To investigative the effect of RMF on bone calcium content and the correlation between bone-specific alkaline phosphatase(BAP) and deoxypyridinoline crosslinks(DPD) in rats.DESIGN:A randomized controlled study in rats.SETTING:A college of life sciences of a university.MATERIALS:The experiment was conducted in Shenzhen Key Lab of Microbiological Genetic Engineering from March 2004 to October 2004,using 90 healthy adult SD rats including 60 females weighing(259± 70) g and 30 males weighing ( 351± 104) g .The rats were randomly divided into 9 groups including 6 ovariotomy groups,namely female sham operation group,normal calcium control group,low calcium control group,low calcium experimental group,normal calcium experimental group,and low calcium group with traditional Chinese medicine(TCM) treatment,besides a male control group,male low calcium experimental group,and male normal calcium experimental group,with 10 rats in each group.INTERVENTIONS:The female rats in each group,except for those in the sham operation group,received ovariotomy.The rats in the ovariotomy control group had only ovariotomy.After metabolic exhaustion of the remnant estrogen on the 15th day,the rats in the ovariotomy experimental group were treated with RMF for 2 hours once a day for 15 days.The male rats,except for those in the control group,all had RMF in identical manner.The rats were given food with normal calcium(containing 0.26% calcium),lower calcium(containing 0.1% calcium) and traditional Chinese medicine(powder of Fructus Psoraleae,Radix Astragali,epimedium herb,and herba cistanchis) . After RME treatment,the rats were fed for another 15 days before the femur was collected to measure the bone calcium content.Serum samples were also obtained for measuring the content of BAP and urine samples collected to measure the content of DPD.MAIN OUTCOME MEASURES:The bone calcium content of each group and serum BAP and urine DPD.RESULTS:Of the 90 rats used,4 died during the experiment and 86 entered the result analysis.The bone calcium content was increased after RMF treatment,and the content in rats in the low calcium group with ovariotomy and TCM treatment and lower calcium control group with ovariotomy was(0.226 ± 0.015) and(0.206± 0.015) g/g,respectively(t=4.63, P< 0.05).The bone calcium content in the male normal calcium experimental group and male control group was(0.206± 0.031) and(0.199± 0.014) g/g respectively(t=4.21, P< 0.05) .After treatment with RMF,serum BAP content was increased and was(20.52± 1.78) and(15.68± 3.68) U/L in normal calcium experimental and control groups with ovariotomy,respectively(t =4.76,P< 0.05),and(17.69± 3.78) and (8.53± 2.54) U/L in the male low calcium experimental and male control groups,respectively(t =4.59,P< 0.05). Urine DPD after RMF treatment was(86.97± 37.19) and(401.57± 79.34) nmol/L in the low calcium experimental group with TCM treatment and ovariotomy and the low calcium control group with ovariotomy,respectively(t=7.45,P< 0.01),and(97.87± 31.97) and(168.71± 53.19) nmol/L in the male normal calcium experimental and male control groups respectively(t=8.31,P< 0.01). CONCLUSION:RMF can effectively increase bone calcium content in a short time(15 days),and the effect was positively correlated with increased blood BAP and decreased urine DPD.