Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada.
Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Canada.
Sci Rep. 2017 Sep 5;7(1):10527. doi: 10.1038/s41598-017-10317-x.
Bone strength is influenced by mineral density and macro- and microstructure. Research into factors that contribute to bone morphology and strength has focused on genetic, environmental and morphological factors (e.g., body mass index), but little is known regarding the impact of rates of skeletal elongation on adult skeletal morphology and strength. Using micro-CT, we examined the impact of rates of skeletal elongation on bone cortical and trabecular morphology, and on rates of estrogen-dependent bone loss in the tibia in CD-1 mice, and in mice with accelerated skeletal growth (Longshanks). Groups of adult mice (n = 7/group) were subjected to ovariectomy or sham surgeries, scanned for 6 weeks, and indices of bone morphology were collected. Results show that Longshanks mice had significantly less trabecular bone at skeletal maturity, characterized by fewer, thinner trabeculae, and furthermore lost trabecular bone more slowly in response to ovariectomy. Artificial selection for rapid skeletal growth relative to somatic growth thus had a significant impact on trabecular bone morphology in Longshanks. Our data do not unequivocally demonstrate a causal relationship between rapid bone growth and reduced trabecular bone quality, but suggest that rapid linear bone growth may influence the risk of cancellous bone fragility.
骨骼强度受矿物质密度以及宏观和微观结构的影响。研究导致骨骼形态和强度变化的因素主要集中在遗传、环境和形态因素（例如，体重指数）上，但对于骨骼生长速度对成人骨骼形态和强度的影响知之甚少。本研究使用 micro-CT 检查了骨骼生长速度对 CD-1 小鼠和骨骼生长加速（长骨）小鼠胫骨皮质和小梁形态以及雌激素依赖性骨丢失率的影响。将成年小鼠（每组 n = 7）进行卵巢切除术或假手术，并扫描 6 周，收集骨形态学指标。结果表明，Longshanks 小鼠在骨骼成熟时的小梁骨明显较少，表现为小梁数量较少、较薄，并且对卵巢切除术的反应中，小梁骨丢失更慢。与躯体生长相比，对骨骼快速生长的人工选择对 Longshanks 小鼠的小梁骨形态产生了重大影响。我们的数据并没有明确证明快速骨生长与小梁骨质量降低之间存在因果关系，但表明快速线性骨生长可能会影响松质骨脆性的风险。
