Parathyroid Damage in Man: Mechanism of Effect on Serum Levels of Calcium and Phosphorus

THE fall in the concentration of calcium in the serum of rats after parathyroidectomy has recently been shown to precede the expected rise in the concentration of phosphorus (1). This observation of Munson's confirms Greenwald's earlier findings (2) in dogs, and supports the concept that parathyroid hormone acts directly to maintain the level of calcium in the serum. The chance observation of a patient who had marked hypocalcemia but a normal level of serum phosphorus at the time of the first sign of tetany following thyroidectomy for hyperthyroidism led to the search for similar patients to confirm, in man, the foregoing findings in animals. The chance observation of a patient who had marked hypocalcemia but a normal level of serum phosphorus at the time of the first sign of tetany following thyroidectomy for hyperthyroidism led to the search for similar patients to confirm, in man, the foregoing findings in animals.