双膦酸盐的长期治疗增加了骨单位的矿化程度

目的评估双膦酸盐的长期应用对骨单位的次级矿化程度的影响。方法30只1岁龄猎犬按体重随机分成三组(每组雌雄各5只):对照组犬每天口服乳糖,低剂量组和高剂量组犬分别每天口服因卡膦酸钠incadronate0.3mgkg和0.6mgkg。所有犬持续给药3a。处死前进行四环素双标,处死后取左侧第9肋骨进行组织形态计测和次级矿化程度评估。结果组织形态计测表明两个双膦酸盐治疗组的骨激活频率(Ac.f)都明显低于对照组,分别降低了40%和82%。矿化程度的测定表明,低剂量和高剂量双膦酸盐组骨单位内的平均矿化程度(MDMB)都明显高于对照组,分别增加了22%和30%。双膦酸盐组MDMB分布曲线与对照组保持了相同的峰值,并且随治疗剂量的增大逐渐向高矿化端漂移。结论双膦酸盐长期应用明显抑制了骨转换,增加了骨单位的矿化程度。

Long-term bisphosphonate administration increase the degree of mineralization in bone

Objective To evaluate the effects of long-term bisphosphoate(incardronate)administration on the mean degree of secondary mineralization in bone.Methods Thirty adult beagles were allocated randomly into three groups based on their body weights(5 males and 5 females in each group.)Animals in CNT were given lactose 12 mg/kg/day orally,while those in YML and YMH were given incadronate disodium at dose of 0.3 mg/kg/day and 0.6 mg/kg/day orally,respectively for three years.All animals were double-labeled intravenously with oxytetracycline hydrochloride(20 mg/kg) before sacrifice.After necropsy,the left 9 th ribs were excised for evaluation.Results Histomorphometry showed that the activation frequency in YML and YMH were significantly lower than that of CNT,and decreased by 40% and 82%,respectively.The mean degree of mineralization in bone(MDMB) in YML and YMH were significantly higher than that of CNT,and increased by 22% and 30%,respectively.Moreover,the distribution of MDMB showed that a dose-dependent shift toward the higher values in incadronate-treated animals concomitantly with preserved peaks when compared with controls.Conclusions Long-term bisphosphonate administration in higher dose significantly suppresses bone turnover,which increases the degree of mineralization in bone.