Effect of parathyroid extract on citrate metabolism in bone

¹ Departments of Oral and Maxillofacial Surgery and Orthodontics, University of Illinois College of Dentistry, Chicago, Illinois
² Department of Oral and Maxillofacial Surgery and Orthodontics, University of Illinois College of Dentistry, Chicago, Illinois

In studies on the citrate metabolism of bone it has not been possible to distinguish the relatively inert extracellular citrate from the more labile intracellular part. To deal with this problem, the conversion of C¹⁴-labeled sodium pyruvate to citrate was studied in metaphyseal bone slices from normal rabbits and from a group in which bone resorption was produced by parathyroid extract. Under the influence of parathyroid extract there was approximately twice as much radioactive citrate present. This citrate is then available to react with bone matrix to form soluble compounds with calcium, withdrawing this cation from the bone salts and its protein-bound complexes.