Submitted to: Analytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2004
Publication Date: 7/6/2004
Citation: Lin, Y.M., Hillegonds, D.J., Gertz, E.R., Van Loan, M.D., Vogel, J.S. 2004. PROTOCOL FOR ASSESSING BONE HEALTH IN HUMANS BY TRACING LONG-LIVED 41CA ISOTOPE IN URINE, SERUM, AND SALIVA SAMPLES. Analytical Chemistry. 332:193-195. Interpretive Summary: Advances in technology have given scientists new, more efficient, and more accurate ways of study human physiology. One such method is accelerated mass spectrometer (AMS) This methods is so sensitive that it allows for the use of low amounts of tracers and continued monitoring for extended periods of time. The research presented here demonstrates the usefulness of the AMS method for study bone metabolism over time. This technique will be useful in long term studies of osteoporosis.
Technical Abstract: Slow bone turnover rate and large day-to day variation in excreted bone biomarkers create a challenge in assessing bone health in humans. The use of the long-lived radioisotope 41-calcium (41Ca, t1/2 = ~ 105 y), which has a rare natural abundance (41Ca/Ca = ~ 10'15), and Accelerator Mass Spectrometry (AMS), which is able to detect 41Ca tracer show great promise in resolving bone health issues. However, sample processing for AMS measurement is a barrier to widespread 41Ca-AMS application. This communication summarizes an improved protocol for quantifying 41Ca concentrations in biological specimens. This modified protocol demonstrates that we were able to successfully determine 41Ca in urine, serum and also saliva after oral ingestion of 41Ca dose. The sample processing protocol described here is less tedious, and the cost is significantly reduced over previous methods. The meaning of Ca monitoring in saliva is not yet understood, but the equivalence of isotopic concentrations in urine and serum is confirmed.