Simultaneous measurement of bone formation and resorption in vivo.

Bone resorption and formation in terms of milligram of calcium deposited into and released from whole humerus of 15-23 weeks old male rats were assessed, via linear least-squares regression analysis of change in calcium content and 3H-tetracycline kinetics of the bone. The rate of resorption was 0.376 mg calcium per day, while formation was 0.758 mg calcium per day. The data indicate that the computation results in a simultaneous and explicit measurement of bone resorption and formation at the organ level.