Evaluation of urinary cyclic 3'5'-adenosine monophosphate excretion in the differential diagnosis of hypercalcemia.

Abstract

ABSTRACT Urinary cyclic 3′,5′-adenosine monophosphate (cyclic AMP) was determined in two normocalcemic control groups and five groups of hypercalcemic patients. Immunoreactive parathyroid hormone was also measured by immunoassay in many of the patients. Eighteen healthy controls excreted 6.2 ± 0.5 μmoles of cyclic AMP per 24 hr; 28% excreted greater than 7.0 μmoles. Sixteen surgically proven hyperparathyroid patients excreted 7.3 ± 0.7 μmoles/24 hr, not statistically different from normal, but 73% of these patients excreted more than 7 μmoles/ hrs. Urinary cyclic AMP excretion usually decreased in these patients after surgical correction of their hyperparathyroidism. A group of four patients with suspected hyperparathyroidism excreted 5.6 ± 1.2 μmoles/24 hr, no different from either normals or surgically proven hyperparathyroid patients. Plasma parathyroid hormone was inappropriately increased for the serum calcium in all of the patients with proven or suspected hyperparathyroidism in whom it was measured...