Li M, Liang H, Shen Y, Wronski T J
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
Bone. 1999 Feb;24(2):95-100. doi: 10.1016/s8756-3282(98)00167-7.
The purpose of the current report is to compare the skeletal effects of PTH treatment at red (hematopoietic) and yellow (fatty) marrow sites in ovariectomized (ovx) rats. In the first study, mature, slowly growing ovx rats that were 4 months of age and 4 weeks postovariectomy were treated with human parathyroid hormone [hPTH(1-34)] (80 microg/kg, 5 days/week) for 6 weeks. In the second study, aged ovx rats that were 15 months of age and 1 year postovariectomy were treated with PTH according to the same regimen for 10 weeks. The proximal tibial metaphysis (PTM) and first lumbar vertebra (LV), bone sites with red marrow, as well as the distal tibial metaphysis (DTM) and fifth caudal vertebra (CV), bone sites with yellow marrow, were processed undecalcified for quantitative bone histomorphometry. At the end of the first study in mature ovx rats, estrogen depletion induced a 73% loss of cancellous bone in the PTM and a 15% loss in the LV. In contrast, not even a trend for cancellous bone loss was observed in the DTM and CV of vehicle-treated ovx rats. PTH treatment of ovx rats increased cancellous bone volume by 191% in the PTM, 56% in the DTM, 47% in the LV, and 22% in the CV, compared with vehicle treatment of ovx rats. In addition, the hormone markedly increased cancellous bone formation by 177% in the PTM, 679% in the DTM, 309% in the LV, and 833% in the CV. Aged ovx rats (second study) exhibited moderate cancellous osteopenia in the LV but not the CV. PTH treatment increased cancellous bone volume by 67% and 37% and bone formation rate by 635% and 359% in the LV and CV, respectively, compared with vehicle treatment of ovx rats. Although the magnitude of the anabolic response to PTH may vary somewhat within the skeleton, the results indicate that PTH augments cancellous bone mass and markedly stimulates bone formation at skeletal sites, regardless of marrow composition.
本报告的目的是比较甲状旁腺激素（PTH）治疗对去卵巢（ovx）大鼠红骨髓（造血）和黄骨髓（脂肪）部位骨骼的影响。在第一项研究中，对4月龄且卵巢切除术后4周的成熟、生长缓慢的ovx大鼠，用人甲状旁腺激素[hPTH(1-34)]（80微克/千克，每周5天）治疗6周。在第二项研究中，对15月龄且卵巢切除术后1年的老龄ovx大鼠，按照相同方案用PTH治疗10周。近端胫骨干骺端（PTM）和第一腰椎（LV）为红骨髓所在的骨部位，远端胫骨干骺端（DTM）和第五尾椎（CV）为黄骨髓所在的骨部位，对这些部位进行不脱钙处理以进行定量骨组织形态计量学分析。在成熟ovx大鼠的第一项研究结束时，雌激素缺乏导致PTM松质骨丢失73%，LV松质骨丢失15%。相比之下，在接受赋形剂治疗的ovx大鼠的DTM和CV中，未观察到松质骨丢失的趋势。与接受赋形剂治疗的ovx大鼠相比，PTH治疗使ovx大鼠的PTM松质骨体积增加191%，DTM增加56%，LV增加47%，CV增加22%。此外，该激素使PTM松质骨形成显著增加177%；DTM增加679%，LV增加309%，CV增加833%。老龄ovx大鼠（第二项研究）在LV中表现出中度松质骨减少，但在CV中未出现。与接受赋形剂治疗的ovx大鼠相比，PTH治疗使LV和CV的松质骨体积分别增加67%和37%，骨形成率分别增加635%和359%。尽管骨骼对PTH的合成代谢反应程度可能略有不同，但结果表明，无论骨髓成分如何，PTH均可增加松质骨量并显著刺激骨骼部位骨形成。
