Inhibition of bone cell metabolism increases strontium-85 uptake

Summary Experiments have been performed on the canine tibia to investigate whether perturbation of the energy metabolism of bone cells can influence the short-term exchange of bone mineral. Simultaneous injection of three radioactive tracers,¹²⁵I-albumin,⁸⁵Sr, and⁸⁶Rb, into the tibial nutrient artery was followed immediately by measurement of the concentration of these tracers in the venous outflow from the bone for a period of 5 minutes. This procedure was performed before and after the injection of potassium cyanide into the bone. From the measured concentrations, extraction ratios for⁸⁵Sr and⁸⁶Rb with respect to¹²⁵I-albumin were calculated. It was found that net extraction after 5 minutes of⁸⁵Sr was significantly increased. This result indicates that efflux of ions from exchangeable mineral is dependent to a significant extent on the metabolic activity of bone cells.