Cyclic AMP, Urinary Excretion
The differential diagnosis of hypercalcemia
An adjunct to serum parathyroid hormone measurements, especially in the diagnosis of parathyroid hormone resistance states, such as pseudohypoparathyroidism
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Cyclic AMP functions as an intracellular "second messenger" regulating the activity of intracellular enzymes or proteins in response to a variety of hormones (eg, parathyroid hormone).
Urinary cyclic AMP is elevated in about 85% of patients with hyperparathyroidism.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
1.3-3.7 nmol/dL of glomerular filtrate
Urinary cyclic AMP is elevated in about 85% of patients with hyperparathyroidism and in about 50% of patients with humoral hypercalcemia of malignancy.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Parathyroid suppression (hypoparathyroidism) does not lower urinary cyclic AMP excretion to definitely subnormal values.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Aurbach GD, Marx SJ, Spiegel AM: Parathyroid hormone, calcitonin, and the calciferols. In Williams Textbook of Endocrinology. Eighth edition. Edited by JD Wilson, DW Foster. Philadelphia, WB Saunders Company, 1992, pp 1413-1415