Quantitative 45 Ca autoradiography of human bone
Riggs, B.L.; Marshall, J.H.; Jowsey, J.; Heaney, R.P.; Bassingthwaighte, J.B.
Journal of Laboratory and Clinical Medicine 78(4): 585-598
1971
ISSN/ISBN: 0022-2143 PMID: 5286527 Document Number: 40634
Bone from 7 terminally ill men who were given 45Ca 12 h to 23 days before death was studied by quantitative autoradiography. Short-term exchangeable Ca was on bone surfaces and had an apparent mass of 3.4 g. The time of maximum surface 45Ca activity was 2.5 days. Diffuse activity of low intensity from long-term exchange accounted for 16.9+or- 3.3% of total uptake; in the 2 patients having plasma45Ca estimations the rate of diffuse uptake ranged from 10 to 25% of the normal accretion rate. Focal activity of intermediate intensity accounted for 49.8 to 68.4% of uptake and was believed to be caused by both long-term exchange and secondary mineralization. An unexpected finding was that 7.5+or- 1.6% of activity was associated with bone resorption surfaces. Because of the terminal illness, bone formation was suppressed and only 5.9+or- 2.4% of activity was associated with hot spots.