Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK.; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
Centre of Metabolism, Ageing & Physiology (CMAP), MRC-Versus Arthritis Centre of Excellence for Musculoskeletal Ageing Research, Nottingham NIHR Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, UK.; Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences at the University of Nottingham, Nottingham, UK.
Bone. 2024 Dec;189:117257. doi: 10.1016/j.bone.2024.117257. Epub 2024 Sep 17.
Bone is influenced by many factors such as genetics and mechanical loading, but the short-term physiological effects of these factors on bone (re)modelling are not well characterised. This study investigated the effects of endurance trainability phenotype, sex, and interval running training (7-week intervention) on bone collagen formation in rats using a deuterium oxide stable isotope tracer method. Bone samples of the femur diaphysis, proximal tibia, mid-shaft tibia, and distal tibia were collected after necropsy from forty-six 9 ± 3-month male and female rats selectively bred for yielding low (LRT) or high (HRT) responses to endurance training. Bone collagen proteins were isolated and hydrolysed, and fractional synthetic rates (FSRs) were determined by the incorporation of deuterium into protein-bound alanine via GC-pyrolysis-IRMS. There was a significant large main effect of phenotype at the femur site (p < 0.001; η = 0.473) with HRT rats showing greater bone collagen FSRs than LRT rats. There was a significant large main effect of phenotype (p = 0.008; η = 0.178) and a significant large main effect of sex (p = 0.005; η = 0.196) at the proximal site of the tibia with HRT rats showing greater bone collagen FSRs than LRT rats, and male rats showing greater bone collagen FSRs compared to female rats. There was a significant large main effect of training at the mid-shaft site of the tibia (p = 0.012; η = 0.159), with rats that underwent interval running training having greater bone collagen FSRs than control rats. Similarly, there was a significant large main effect of training at the distal site of the tibia (p = 0.050; η = 0.156), with rats in the interval running training group having greater bone collagen FSRs compared to rats in the control group. Collectively, this evidence highlights that bone responses to physiological effects are site-specific, indicating that interval running training has positive effects on bone collagen synthesis at the tibial mid-shaft and distal sites, whilst genetic factors affect bone collagen synthesis at the femur diaphysis (phenotype) and proximal tibia (phenotype and sex) in rats.
骨骼受到许多因素的影响，如遗传和机械加载，但这些因素对骨骼（重塑）的短期生理影响尚未得到很好的描述。本研究使用氘水稳定同位素示踪法，研究了耐力训练表型、性别和间歇跑训练（7 周干预）对大鼠骨骼胶原形成的影响。在 46 只 9±3 月龄的雄性和雌性大鼠死后，从股骨骨干、胫骨近端、胫骨中段和胫骨远端采集骨骼样本，这些大鼠是为了对耐力训练产生低（LRT）或高（HRT）反应而选择性繁殖的。分离和水解骨胶原蛋白，并通过 GC-热解-IRMS 将氘掺入蛋白结合的丙氨酸中，确定分数合成率（FSR）。在股骨部位有显著的大表型主效应（p<0.001；η=0.473），HRT 大鼠的骨胶原 FSR 高于 LRT 大鼠。在胫骨近端部位有显著的大表型主效应（p=0.008；η=0.178）和显著的大性别主效应（p=0.005；η=0.196），HRT 大鼠的骨胶原 FSR 高于 LRT 大鼠，雄性大鼠的骨胶原 FSR 高于雌性大鼠。在胫骨中段部位有显著的大训练主效应（p=0.012；η=0.159），间歇跑训练组的大鼠骨胶原 FSR 高于对照组。同样，在胫骨远端部位有显著的大训练主效应（p=0.050；η=0.156），间歇跑训练组的大鼠骨胶原 FSR 高于对照组。总的来说，这些证据表明，骨骼对生理效应的反应是特定部位的，表明间歇跑训练对胫骨中段和远端的骨胶原合成有积极影响，而遗传因素则影响股骨骨干（表型）和胫骨近端（表型和性别）的骨胶原合成。
