Abstract
Parathyroid hormone in human blood was determined by the method of radioimmunoassay using guinea pig antibody to bovine parathyroid hormone and 125I labeled highly purified bovine parathyroid hormone, with the separation of bound and free fraction by means of adsorption to dextran coated charcoal. Parathyroid hormone in normal subjects tended to decline with advancing age in both males and females. In most of the cases of primary hyperparathyroidism, parathyroid hormone in blood was increased above the normal range, and a decrease followed removal of the adenoma. Parathyroid hormone in blood was also increased in many cases of secondary hyperparathyroidism because of chronic renal failure, 2 cases of renal tubular acidosis, and 1 case of vitamin D resistant rickets. Parathyroid hormone was undetectable in blood of patients with postaperative and idiopathic hypoparathyroidism but was elevated in 2 cases of pseudohypoparathyroidism. EDTA-induced hypocalcemia caused an increase of parathyroid hormone in blood in normal subjects of various ages with and without osteoporosis, but not in patients with postoperative and indiopathic hypoparathyroidism. Radioimmunoassay of parathyroid eormone in blood thus appears to be useful in the diagnosis of various diseases of the parathyroids, although the sensitivity of the present assay method is somewhat limited because of the difference in the immunological properties between human and bovine parathyroid hormone.
