Improved radioenzymatic assay for plasma norepinephrine using purified phenylethanolamine n-methyltransferase

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5436062

Bowsher, R R; Henry, D P

Radioenzymatic assays have been developed for catecholamines using either catechol O-methyltransferase (COMT) or phenylethanolamine N-methyltransferase (PNMT). Assays using PNMT are specific for norepinephrine (NE) and require minimal manipulative effort but until now have been less sensitive than the more complex procedures using COMT. The authors report an improved purification scheme for bovine PNMT which has permitted development of an NE assay with dramatically improved sensitivity (0.5 pg), specificity and reproducibility (C.V. < 5%). PNMT was purified by sequential pH 5.0 treatment and dialysis and by column chromatographic procedures using DEAE-Sephacel, Sepharcryl S-200 and Phenyl-Boronate Agarose. Recovery of PNMT through the purification scheme was 50%, while blank recovery was <.001%. NE can be directly quantified in 25 ul of human plasma and an 80 tube assay can be completed within 4 h. The capillary to venous plasma NE gradient was examined in 8 normotensive male subjects. Capillary plasma (NE (211.2 +/- 61.3 pg/ml)) was lower than venous plasma NE (366.6 +/- 92.5 pg/ml) in all subjects (p < 0.005). This difference suggests that capillary (NE) may be a unique indicator of sympathetic nervous system activity in vivo. In conclusion, purification of PNMT has facilitated development of an improved radioenzymatic for NE with significantly improved sensitivity.

• Research Organization: Eli Lilly and Co., Indianapolis, IN
• OSTI ID: 5436062
• Report Number(s): CONF-8604222-; TRN: 86-026626
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NORADRENALINE
RADIOENZYMATIC ASSAY
TRANSFERASES
PURIFICATION
BLOOD PLASMA
CATTLE
LIQUID COLUMN CHROMATOGRAPHY
ADRENAL HORMONES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL MATERIALS
BLOOD
BODY FLUIDS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CHROMATOGRAPHY
DOMESTIC ANIMALS
DRUGS
ENZYMES
HORMONES
MAMMALS
MATERIALS
NEUROREGULATORS
RUMINANTS
SEPARATION PROCESSES
STEROID HORMONES
SYMPATHOMIMETICS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques