不同频度PTH rP1-34对去卵巢大鼠骨密度和生物力学性能的影响

Effect of different administration frequency ofPTHrP1-34 on the osteoporosis ofthe ovariectomized rats

目的研究不同频度给予甲状旁腺激素相关肽(PTH rP 1-34)对去卵巢大鼠腰椎和股骨骨密度(BM D)及生物力学性能的影响。方法将70只大鼠分为7组,即假手术对照组(Sham组)、去卵巢对照组(OVX组)、苯甲酸雌二醇治疗组(E组)、PTH rP 1-34治疗组(包括P 1D组、P 2D组、P 3D组、P 1W组)。去卵巢4周后,后四组均给予PTH rP 1-34 40μg/kg,分别按1次/d、1次/2d、1次/3d、1次/周皮下注射。治疗12周后处死大鼠,分离股骨、腰椎并测量其BM D,股骨做三点弯曲试验,第五腰椎做压缩试验。结果卵巢摘除术后,OVX组BM D较Sham组明显降低,表明大鼠骨质疏松模型建模成功。P 1D组和P 2D组股骨及腰椎BM D、最大载荷和弹性模量显著高于OVX组(P<0.05),与Sham组无统计学差异。结论PTH rP 1-34 40μg/kg剂量,1次/d或1次/2d皮下注射,可以提高去卵巢大鼠的BM D,改善其生物力学特性,有效地防治骨质疏松。

Objective： To investigate the effect of different administration frequency of parathyroid hormonerelated peptide （PTHrP1-34） on the osteoporosis of the ovariectomized rats. Methods： 70 female Wistar rats of 4-month age were randomly divided into 7 groups of Sham, OVX, E, P1D, P2D, P3D and P1W, The 10 rats of Sham group were sham-operated and the rest was ovariectomized. After 4 weeks, the rats of P1D, P2D, P3D and P1W groups were subcutaneously injected with 40μg/kg PTHrPI-34 once a day, once every other day,once every 3 days and once a week respectively, The E group rats received estradiol benzoate at a dosage of 40μg/kg once every 3 days and the control groups OVX and Sham were injected with 0.2ml saline once a day, After treatment of 12 weeks, the femora and lumbar vertebrae were removed for the determination of the bone mineral density （BMD） and bone biomechanical test, Result： After 16 weeks ofovariectomy the lumbar BMD and bone maximum load of the OVX group rats were significantly declined compared with that of sham-operated rats, which means the osteoporotic animal model was successful, The BMD and bone maximum load of the P1D and P2D groups were significantly bigber than that of OVX group and almost close to that of E group, Conclusions： Once a day or once every other days＇ subcutaneous administration of 40μg/kg of PTHrP1-34 may be an efficient dosage for the treatment of the osteoporotic rats.