Measurement of Age - Related Changes in Bone Matrix Using ²H₂O Labeling

摘要: Age-related changes in bone metabolism are well established by biochemical markers of matrix serum and urine, but analysis the residual matrix, which is still turning over, has not been investigated. In present study, we measured vivo rates protein synthesis using a precursor-product method based on exchange ²H from ²H₂O into amino acids. Four percent was administered to mice drinking water after intraperitonial (i.p) bolus injection 99.9% ²H₂O. Mice were divided two groups: growing young 4% for 12 weeks an i.p at 5 week age, whereas weight stable adult started 8 later than group continued weeks. Mass isotopomer abundance alanine analyzed gas chromatography/mass spectrometry. Body enrichments range 1.88~2.41% over labeling period. The fractional (ks) 2.000±0.071%/d 0.243±0.014%/d mice. These results demonstrate that rate decreases with age direct evidence age-related synthesis.