A more sensitive and specific radioenzymatic assay for catecholamines

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(90)90314-H· OSTI ID:5935551

Kennedy, B; Ziegler, M G ^[1]

---

1. Univ. of California, San Diego (USA)

This modification of the catechol-O-methyltransferase (COMT) based radioenzymatic assay for norepinephrine (NE) and epinephrine (E) improves sensitivity, selectivity and eliminates many inhibitors of COMT. Prior to assay, samples are extracted into heptane with diphenylborate, then into dilute acetic acid. This extraction procedure has an efficiency of 78% for NE but less than 2% for S-adenosylmethionine (SAM). The extraction procedure also excludes calcium and other COMT inhibitors present in urine, plasma and every tissue tested. This eliminates the requirement for individual standardization of tissue and urine samples. Sensitivity of the assay for NE and E is 10 and 6 pg/ml respectively in 1 ml of plasma. The intraassay coefficients of variation for NE and E are 4 and 13% and the interassay coefficients of variation for NE and E are 10 and 16% in a human plasma sample containing low catecholamine levels. The assay permits quantitation of plasma E levels that were undetectable in prior assays.

• OSTI ID: 5935551
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 47:23; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ADRENALINE
AMINES
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATECHOLAMINES
DRUGS
ENZYMES
EXTRACTION
HYDROXY COMPOUNDS
METHYL TRANSFERASES
NEUROREGULATORS
NORADRENALINE
ORGANIC COMPOUNDS
PHENOLS
POLYPHENOLS
RADIOENZYMATIC ASSAY
SENSITIVITY ANALYSIS
SEPARATION PROCESSES
SOLVENT EXTRACTION
SYMPATHOMIMETICS
TRANSFERASES