EVALUATION OF A RADIO-ENZYMIC KIT FOR DETERMINATION OF PLASMA-CATECHOLAMINES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 26  (1) , 120-122
Abstract
A commercially available reagent test-kit for simultaneously determining norepinephrine, epinephrine and dopamine in 50 .mu.l of plasma was evaluated. The 3 catecholamines are enzymically converted into the radioactive O-methyl derivatives and separated by TLC. Day-to-day precision was 11, 10 and 14% for norepinephrine, epinephrine and dopamine, respectively. The relationship between concentration of catecholamine and radioactivity (net dpm) was linear to at least 8 ng (corresponding to 1 .mu.mol/l in plasma). Sensitivity was .apprx. 2 pg for dopamine, 1 pg for each of the other 2 catecholamines. Under the conditions, epinephrine was not quite completely resolved from the other 2 fractions. Catecholamine values determined in normal humans, after 30 min supine and after normal laboratory activity, agreed well with those found by other investigators. Correlation was good between kit results and those obtained in another laboratory that used self-prepared reagents and high-performance liquid chromatography for the separation.