Collagen turnover and isotopic records in cortical bone
Collagen turnover and isotopic records in cortical bone
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DOI：
10.1016/j.jas.2019.03.010
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发表时间：
2019-06
影响因子：
2.8
通讯作者：
Jun Matsubayashi;I. Tayasu
中科院分区：
文献类型：
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作者：
Jun Matsubayashi;I. Tayasu
现代和古代动物的骨胶原是用于同位素分析的有用组织，因为它随时间推移而稳定。然而，骨胶原代谢周转过程的不确定性可能使同位素分析难以与相关的生活史信息相关联。我们使用放射性碳（14 C）测年检查皮质骨内的营业额，并调查回顾性同位素比值沿着几个大型哺乳动物的股骨中段的生长方向，具有较长的寿命，包括棕熊（熊），西卡（鹿），日本serow（山羊），日本猕猴（猕猴）。这些人死于1971年至1986年之间，因此他们的骨头被认为含有核弹试验产生的放射性碳，这导致了1964年左右的大气14 C峰值。因此，14 C测年法可用于精细尺度的皮质骨切片测年。除日本serow标本外，所有标本骨切片中的14 C年龄显示出相似的趋势;髓周骨切片中含有较年轻的碳，在14 C峰值后，14 C已耗尽，而14 C年龄在中皮质切片中迅速变老，然后逐渐变年轻。我们在髓周骨切片中观察到骨重建驱动的胶原代谢周转，但在皮质中部和皮质周切片中没有观察到重建的证据。因此，我们的研究结果证实，骨胶原在股骨皮质骨记录回顾性同位素信息在骨骼生长的哺乳动物，并建议，整个股骨皮质骨的老年陆生哺乳动物代表同位素值在青春期，而不是从几年前死亡的平均值。
Bone collagen of modern and ancient animals is a useful tissue for isotope analyses because it is stable over time. However, uncertainty regarding metabolic turnover processes of bone collagen can make isotope analysis difficult to correlate with relevant life history information. We used radiocarbon (14C) dating to examine turnover within cortical bone and to investigate retrospective isotope ratios along the growth direction of mid-shaft femurs of several large mammals with long life-span, including brown bear (Ursus arctos), sika deer (Cervus nippon), Japanese serow (Capricornis crispus), and Japanese macaque (Macaca fuscata). The individuals examined died between 1971 and 1986, and their bones were thus expected to contain radiocarbon generated by nuclear bomb testing, which led to an atmospheric14C spike around 1964. Therefore,14C dating could be used to date sections of cortical bone at fine scale. The14C ages in the bone sections of all specimens except the Japanese serow specimen showed similar trends; perimedullary bone sections contained younger carbon, which has depleted14C after the peak of the14C spike, whereas14C ages became rapidly older in midcortical sections before gradually becoming younger towards the bone surface. We observed metabolic turnover of collagen driven by bone remodelling in perimedullary bone sections, but we observed no evidence of remodelling in midcortical and pericortical sections. Thus, our results confirm that bone collagen in femoral cortical bone records retrospective isotopic information during skeletal growth of mammals and suggest that entire femoral cortical bone of aged terrestrial mammals represents isotopic values during adolescence rather than an average value from several years prior to death.