去卵巢大鼠骨密度对间歇性注射重组人甲状旁腺激素的反映

Effect of intermittent injection of recombinant human parathyroid hormone on bone mineral density of ovariectomized rats

目的:探讨间歇性注射重组人甲状旁腺激素1-84(rhPTH1-84)对去卵巢大鼠骨矿密度的影响。方法:6月龄雌性未育SD大鼠随机分成3组(每组6只):去卵巢安慰剂组,去卵巢治疗组,假手术安慰剂组。去卵巢治疗组大鼠在术后3～4.5个月期间给予每日皮下注射rhPTH1-84(20μg/100g),每周6次,共6周,另两组则注射PTH溶媒(含0.01g/L乙酸的PBS),各组大鼠均在术前、术后3和4.5个月用双能X线骨密度仪测腰椎和右股骨上端骨矿密度。结果:去卵巢安慰剂组大鼠在术后3和4.5月时腰椎骨矿密度与术前比无明显变化(P>0.05),去卵巢治疗组大鼠经PTH治疗6周后腰椎骨矿密度升高了(0.0157±0.0095)g/cm2,而去卵巢安慰剂组下降了(0.0138±0.0088)g/cm2,去卵巢治疗组和去卵巢安慰剂组腰椎骨矿密度变化值差别显著(P<0.01);各组大鼠股骨上端骨矿密度均上升且上升幅度相似(P>0.05)。结论:间歇性注射rhPTH1-84能明显提高去卵巢大鼠腰椎骨矿密度,但对股骨上端骨矿密度无明显影响。这些结果提示间歇性注射PTH主要影响骨松质而不是皮质骨。

AIM:To probe into the effect of intermittent injection of recombinant human parathyroid hormone on bone mineral density(BMD) of ovariectomized rats. METHODS:The 6-month-old female SD rats were randomly divided into 3 groups:ovariectomized for placebo injection (OVXE,n=6),ovariectomized for PTH treatment(OVXEP,n=6),sham-operated for placebo injection(ShamE,n=6).During 3-4.5 months after operation,OVXEP rats received daily subcutaneous injection of rhPTH1-84(20 μg/100 g),six times a week for six weeks,while the other 2 groups received PTH solvent injection(PBS of 0.01 acetic acid ).The rates of the three groups were measured the BMD of lumbar vertebrae and right proximal femur with dual energy X-ray absorptiometry during 3-4.5 months after operation. RESULTS:The BMD of lumbar vertebrae of OVXE rats at 3 and 4.5 months after ovariectomy changed little(P >0.05).After 6-week intermittent injection of rhPTH1-84,the BMD of lumbar vertebrae of OVXEP rats had increased by (15.7±9.5) mg/cm2,while that of OVXE had decreased by(13.8±8.8) mg/cm2;the changes between OVXE and OVXEP were significant(P< 0.01).The BMD of proximal femur in these 3 groups had simultaneously increased and the rising range was similar(P >0.05). CONCLUSION:Short-term intermittent injection of rhPTH1-84 can significantly increase the BMD of lumbar vertebrae in ovariectomized rats,but can not significantly affect the BMD of proximal femur.These results suggest that intermittent PTH application mainly affects on spongy bone rather than on cortical bone.