PMID- 8738181
OWN - NLM
STAT- MEDLINE
DCOM- 19961021
LR  - 20190815
IS  - 0731-7085 (Print)
IS  - 0731-7085 (Linking)
VI  - 14
IP  - 5
DP  - 1996 Mar
TI  - Validation of assay of catechol-O-methyltransferase activity in human 
      erythrocytes.
PG  - 515-23
AB  - The multistep assay of specific catechol-O-methyltransferase (COMT) activity in 
      human erythrocytes was validated. Enzyme preparations from lysed erythrocytes 
      were incubated with a substrate (3,4-dihydroxybenzoic acid) in the presence of 
      Mg2+ and S-adenosylmethionine. The reaction products (vanillic acid and 
      isovanillic acid) were analyzable by HPLC with electrochemical detection directly 
      in the incubation medium after protein precipitation. The precision was 
      calculated in order to define the random variability associated with the method 
      by intra-assay and inter-assay relative standard deviations (RSDs) for the assays 
      of both reaction products and protein. The intra-assay RDSs for the specific 
      activities were between 4.8 and 11.9% (n = 5-6) at two levels of COMT activity. 
      The inter-assay RSDs were between 6.4 and 14.2% (n = 5-6), respectively. The 
      total variation was mostly caused by the protein assay and the HPLC assay, and 
      contributions from the sample preparation and incubation steps were minor. Some 
      results from the clinical application of the erythrocyte COMT assay are also 
      reported. For both normal volunteers and patients having Parkinson's disease, a 
      single 400 mg dose of entacapone, a peripherally acting COMT inhibitor, decreased 
      the erythrocyte COMT activity. The application demonstrates that the assay was 
      able to detect differences between the subjects and the effect of COMT inhibition 
      in the clinical study.
FAU - Tuomainen, P
AU  - Tuomainen P
AD  - University of Helsinki, Department of Pharmacology and Toxicology, Helsinki, 
      Finland.
FAU - Reenila, I
AU  - Reenila I
FAU - Mannisto, P T
AU  - Mannisto PT
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Pharm Biomed Anal
JT  - Journal of pharmaceutical and biomedical analysis
JID - 8309336
RN  - 0 (Blood Proteins)
RN  - 0 (Catechols)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Nitriles)
RN  - 4975G9NM6T (entacapone)
RN  - EC 2.1.1.6 (Catechol O-Methyltransferase)
SB  - IM
MH  - Blood Proteins/analysis
MH  - Catechol O-Methyltransferase/*blood
MH  - Catechols/therapeutic use
MH  - Chromatography, High Pressure Liquid
MH  - Electrochemistry/methods
MH  - Enzyme Inhibitors/therapeutic use
MH  - Enzyme Stability
MH  - Erythrocytes/*enzymology
MH  - Humans
MH  - Methylation
MH  - Nitriles
MH  - Parkinson Disease/drug therapy/enzymology
MH  - Reproducibility of Results
MH  - Sensitivity and Specificity
EDAT- 1996/03/01 00:00
MHDA- 1996/03/01 00:01
CRDT- 1996/03/01 00:00
PHST- 1996/03/01 00:00 [pubmed]
PHST- 1996/03/01 00:01 [medline]
PHST- 1996/03/01 00:00 [entrez]
AID - 0731-7085(95)01645-7 [pii]
AID - 10.1016/0731-7085(95)01645-7 [doi]
PST - ppublish
SO  - J Pharm Biomed Anal. 1996 Mar;14(5):515-23. doi: 10.1016/0731-7085(95)01645-7.