低钙饮食对雄性大鼠松质骨和密质骨影响的比较

目的　比较低钙饮食对大鼠胫骨上段松质骨和胫骨中段密质骨的影响。方法　实验用 3月龄SD雄性大鼠 2 0只 ,随机分为正常年龄对照组 (control)、极低钙组 (VLCD)、低钙组 (LDC)。Control组饲养正常饲料 ,VLCD组饲养 0 0 1%含钙饲料 ,LCD组饲养 0 3%含钙饲料。 3个月后取各组大鼠左侧胫骨近心端和中段 ,行不脱钙骨制片 ,进行骨组织形态计量学测量。结果　松质骨 :与对照组相比 ,VLCD组和LCD组的大鼠骨量减少 ,骨小粱面积百分率 (%Tb .Ar)分别减少 5 7% (P <0 0 1)和4 0 % (P <0 0 5 ) ,骨结构参数变差 ,代表骨形成指标荧光周长百分数 (L .Pm % )、矿化沉积率 (MAR)、骨形成率 (BFR/BV)有增加的趋势。VLCD组骨吸收参数骨小粱周长破骨细胞数量 (N .OC/Tb .Pm)有显著增加 ,呈现骨高转化的改变。密质骨 :与对照组相比 ,VLCD组和LCD组的骨量有减少的趋势 ,骨外膜面代表骨形成的参数增加 ,骨内膜代表骨形成的参数变化不大 ,骨内膜骨吸收增加。结论　低钙饮食使骨量减少 ,但不同的部位有不同的骨丢失速度

The comparison of the effect of low calcium diet on trabecular and cortical bone in male rats

Objective To study the skeletal effects of low calcium diet in male rats on the histomorphometry of rat skeleton. Methods Twenty Sprague Dawley male rats (3 month old) were randomly divided into three groups,control group,very low calcium diet group(VLCD),low calcium diet group(LCD). After 90 days,the proximal tibial metaphysis(PTM) and the middle part of tibial shafts(Tx) were processed undecalcified for quantitive bone histomorphometry. Results PTM:VLCD and LCD group had lost cancellous bone compared with control group by 3 months,respectively. Bone formation indices such as percent labeled perimeter(L.Pm%),mineral apposition rate(MAR) and bone formation rate(BFR/BV) were increased without significance in VLCD group. Bone resorption indices such as Osteoclast number per mm(Oc.N/Tb.Pm) in VLCD group increased. The effect in LCD was lessen than in VLCD. TX:VLCD and LCD group VS control group,the cortical bone of tibil shaft and bone formation infices in periosteal surface of Tx were increase. Bone resorption indices in the endocortical surface were increase too. Conclusion The results show that low calcium diet has significant effect on the proximal tibial metaphysis and the middle part of tibial shafts. These indicate that different part of the bone have different reation to low calcium diet.