Bone matrix turnover and balance in vitro: <i>II. The effects of ageing</i>

Barry Flanagan; George Nichols

doi:10.1172/JCI106019

^{Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115}

^{Peter Bent Brigham Hospital, Boston, Massachusetts 02115}

^{Boston City Hospital, Boston, Massachusetts 02118}

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^{Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115}

^{Peter Bent Brigham Hospital, Boston, Massachusetts 02115}

^{Boston City Hospital, Boston, Massachusetts 02118}

Find articles by Nichols, G. in: PubMed | Google Scholar

Published in Volume 48, Issue 4 on April 1, 1969
J Clin Invest. 1969;48(4):607–612. https://doi.org/10.1172/JCI106019.
© 1969 The American Society for Clinical Investigation

Published April 1, 1969 - Version history

The rates of both formation and resorption of bone collagen may be accurately quantitated by kinetic analysis of hydroxyproline metabolism in vitro. Using this approach we have studied the changes in bone collagen turnover with age in the rat. The rates of synthesis and resorption of collagen decline with age although the resorptive activity per cell increases up to 6 months of age. The solubility of collagen declines with age. The fraction of the newly synthesized collagen which is deposited as matrix declines dramatically with age revealing a new and hitherto unsuspected aspect of the osteoporotic process. The collagen balance becomes progressively more negative over the 1st 6 months of life. These results indicate that even in an animal who is not subject to clinical osteoporosis, biochemical measurement reveals that such a trend exists. The application of this approach to human subjects is feasible and has important implications.