Lee Seungyong, Prisby Rhonda D
Department of Kinesiology, University of Texas at Arlington, Arlington, TX 76019, United States of America.
Bone Rep. 2018 Dec 30;10:100193. doi: 10.1016/j.bonr.2018.100193. eCollection 2019 Jun.
Intermittent parathyroid hormone (PTH) administration augments bone and progressive bone marrow blood vessel (BMBV) ossification occurs with advancing age. Since intermittent PTH administration augments bone, it may also serve to increase BMBV ossification. We assessed the influence of 5- and 10-days of intermittent PTH 1-34 administration on trabecular and cortical bone and BMBV ossification in mature (6-8 mon; n = 30) and middle-aged (10-12 mon; n = 30) male and female C57BL/6 mice. Mice were divided accordingly: control (CON) and 5-days (5dPTH) and 10-days (10dPTH) of PTH. Mice were given PBS (50 μl) or PTH 1-34 (43 μg/kg/d) for 5- and 10-consecutive days. Trabecular bone microarchitecture (i.e., BV/TV [%], Tb.Th [μm], Tb.N [/mm], and Tb.Sp [μm]) was assessed in the distal femoral metaphysis and cortical bone parameters (i.e., Ct.Th [μm] and CSMI [mm]) at the femoral mid-shaft. BMBV ossification (i.e., ossified vessel volume [OsVV, %] and ossified vessel thickness [OsV.Th, μm]) was assessed in the medullary cavity of the femoral shaft. All parameters were determined by μCT. At this sample size, no gender-related differences were observed so female and male data were pooled. There were no main effects nor interactions for trabecular microarchitecture and Ct.Th. However, CSMI was larger (p < 0.05) in Middle-Age vs. Mature and larger (p < 0.05) in CON and 10dPTH vs. 5dPTH. OsVV tended (p = 0.057) to be higher (0.18 ± 0.04% vs. 0.09 ± 0.02%, respectively) and OsV.Th was higher (p < 0.05; 17.4 ± 1.6 μm vs. 12.1 ± 1.4 μm, respectively) in Middle-Aged vs. Mature mice. OsVV was not altered, but ossified vessels tended (p = 0.08) to be thicker in 10dPTH (17.6 ± 2.0 μm) vs. CON (12.5 ± 1.7 μm). No interactions were observed for OsVV and OsV.Th. In conclusion, this is the first report of ossified BMBV in C57BL/6 mice. The increased OsV.Th in Middle-Aged mice coincides with previous reports of increased OsVV in aged rats. The tendency of augmented OsV.Th in 10dPTH suggests that this treatment may ultimately impair the patency of bone marrow blood vessels.
间歇性给予甲状旁腺激素（PTH）可增强骨量，且随着年龄增长会出现渐进性骨髓血管（BMBV）骨化。由于间歇性给予PTH可增强骨量，它可能也有助于增加BMBV骨化。我们评估了连续5天和10天给予PTH 1-34对成熟（6-8月龄；n = 30）和中年（10-12月龄；n = 30）雄性和雌性C57BL/6小鼠小梁骨和皮质骨以及BMBV骨化的影响。小鼠被相应分为：对照组（CON）、5天PTH组（5dPTH）和10天PTH组（10dPTH）。连续5天和10天给小鼠注射磷酸盐缓冲液（PBS，50μl）或PTH 1-34（43μg/kg/d）。在股骨远端干骺端评估小梁骨微结构（即骨体积分数[BV/TV，%]、骨小梁厚度[Tb.Th，μm]、骨小梁数量[Tb.N，/mm]和骨小梁间距[Tb.Sp，μm]），在股骨干中段评估皮质骨参数（即皮质骨厚度[Ct.Th，μm]和皮质骨面积指数[CSMI，mm]）。在股骨干髓腔评估BMBV骨化（即骨化血管体积[OsVV，%]和骨化血管厚度[OsV.Th，μm]）。所有参数均通过显微计算机断层扫描（μCT）测定。在此样本量下，未观察到性别相关差异，因此将雌雄数据合并。小梁微结构和Ct.Th无主效应和交互作用。然而，中年组的CSMI大于成熟组（p < 0.05），CON组和10dPTH组的CSMI大于5dPTH组（p < 0.05）。中年小鼠的OsVV有升高趋势（p = 0.057）（分别为0.18±0.04%和0.09±0.02%），OsV.Th更高（p < 0.
