Arginine Vasopressin, Plasma Vasopressin, Arginine • • •

Alphabetical Test Section 252X Extraction, radioimmunoassay (RIA) radioimmunoassay Extraction, 1.0 pg/mL sensitivity: Analytical Clinical Background or (AVP), vasopressin Arginine is a (ADH), hormone antidiuretic hypo- the by produced nonapeptide the from and released thalamus pituitary to posterior in response and hyperosmolarity fluid extracellular concen- promotes AVP hypovolemia. water increasing by urine the of tration tubules. the kidney in reabsorption causes action AVP Inadequate (DI), a syndrome insipidus diabetes nonglycosuric by characterized and dehydration. polydipsia, polyuria, AVP to insufficient DI refers Central hypo- of the due to diseases release pituitary pituitarythalamus, stalk, and result of DI is the Nephrogenic gland. to AVP renal responsiveness impaired to renal or due may be congenital and hypercalcemia, hypokalemia, disease, (eg, multiple disorders systemic or drugs and amyloidosis), myeloma and lithium or demeclocycline (eg, ethanol). presence on the is based DI diagnosis in- serum with of hyperosmolar urine. Central and dilute appropriately can be differentiated DI nephrogenic level and AVP plasma the by measuring simul- light of the it in interpreting osmolality. plasma taneous inappropriate syndrome of The hormone of antidiuretic secretion by hyponatremia is manifest (SIADH) and inappropriately concentrated by is confirmed The diagnosis urine. levels in- AVP or urine plasma serum osmolality. for appropriate Method • • Specimen Requirements plasma frozen EDTA 4 mL minimum 1.1 mL tube; blood in prechilled Draw in refrigerated immediately centrifuge centrifuge. 27 Central DI Central Phenothiazine, carbamazepine Phenothiazine, Nephrogenic DI Nephrogenic Ectopic ADH syndrome Ectopic SIADH • •• • • • Diagnose syndrome of inappropriate inappropriate of syndrome Diagnose (SIADH) secretion ADH Differential diagnosis of central DI diagnosis vs Differential DI nephrogenic Diagnose central diabetes insipidus diabetes central Diagnose (DI) 1.0-13.3 pg/mL 1.0-13.3 1 μU 2.5 pg = Note: Interpretive Information Interpretive Reference Range Reference Clinical Use Arginine Vasopressin, Plasma Vasopressin, Arginine • • •