TY - JOUR
T1 - Microassay of human erythrocyte catechol-O-methyltransferase
T2 - Removal of inhibitory calcium ion with chelating resin
AU - Raymond, F. A.
AU - Weinshilboum, R. M.
N1 - Funding Information:
We thank Luanne Olson for her assistance with these studies, and we thank Dr T.P. Dousa and Dr F.G. Knox for the use of their Jarrell Ash atomic absorption spectrophotometer. This study was supported in part by a faculty development award in clinical pharmacology sponsored by the Pharmaceutical Manufacturers Association Foundation, Inc. (R.M.W.).
PY - 1975
Y1 - 1975
N2 - A radiochemical micromethod for the determination of catechol-O-methyltransferase (COMT) activity in human red blood cells (RBC) is described. The method avoids artifacts that occur with other assay procedures. Erythrocyte lysates are exposed to a particulate chelating agent (Chelex-100) to remove endogenous divalent cations that inhibit COMT. 3,4-Dihydroxybenzoic acid rather than norepinephrine is used as a substrate to increase both the sensitivity and the reproducibility of the procedure. An internal standard of purified rat liver COMT is added to lysates to detect possible variations in endogenous activators or inhibitors of the enzyme. Blood samples from 373 unselected subjects age 16-18 were assayed for RBC COMT activity with this assay procedure. The COMT activity in these blood samples ranged from 3-25 units with a mean activity of 11.3 ± 4.2 (mean ±S.D.).
AB - A radiochemical micromethod for the determination of catechol-O-methyltransferase (COMT) activity in human red blood cells (RBC) is described. The method avoids artifacts that occur with other assay procedures. Erythrocyte lysates are exposed to a particulate chelating agent (Chelex-100) to remove endogenous divalent cations that inhibit COMT. 3,4-Dihydroxybenzoic acid rather than norepinephrine is used as a substrate to increase both the sensitivity and the reproducibility of the procedure. An internal standard of purified rat liver COMT is added to lysates to detect possible variations in endogenous activators or inhibitors of the enzyme. Blood samples from 373 unselected subjects age 16-18 were assayed for RBC COMT activity with this assay procedure. The COMT activity in these blood samples ranged from 3-25 units with a mean activity of 11.3 ± 4.2 (mean ±S.D.).
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U2 - 10.1016/S0009-8981(75)80012-X
DO - 10.1016/S0009-8981(75)80012-X
M3 - Article
C2 - 235384
AN - SCOPUS:0016431055
SN - 0009-8981
VL - 58
SP - 185
EP - 194
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
IS - 2
ER -