Assessment of acute and chronic changes in parathyroid hormone secretion by a radioimmunoassay with predominant specificity for the carboxy-terminal region of the molecule.

A sensitive RIA for parathyroid hormone (PTH) with specificity for the carboxy-terminal region of the hormone was developed and applied to clinical studies. The assay was useful in identifying patients with chronic hyperparathyroid states, such as primary and secondary hyperparathyroidism. In addition, the assay could detect acute changes in PTH seen during calcium, pentagastrin, and EDTA infusions and after parathyroidectomy. These studies demonstrated that an immunoassay with predominant specificity for the carboxy-terminal fragment of PTH can be used to evaluate acute as well as chronic changes in hormone secretion.