A method for the measurement of catechol-O-methyltransferase activity using norepinephrine, an endogenous substrate

The Analyst
M TsunodaK Imai


We propose a highly sensitive method for the measurement of catechol-O-methyltransferase (COMT) activity with norepinephrine (NE), an endogenous native substrate. The product, normetanephrine, was determined by high-performance liquid chromatography (HPLC)-peroxyoxalate chemiluminescence reaction detection or, if required, less sensitive fluorescence detection. For the measurement of membrane-bound (MB)-COMT activity in the rat erythrocyte, the HPLC-peroxyoxalate chemiluminescence reaction detection was employed. Soluble (S)- and MB-COMT activities in the rat erythrocyte were 22.9 +/- 2.5 and 4.62 +/- 1.23 pmol min-1 (mg protein)-1, respectively (n = 5). The Km values obtained for S- and MB-COMT were 366 +/- 31 mumol l-1 and 12.0 +/- 1.1 mumol l-1, respectively (n = 5), suggesting that the use of NE as a substrate would give more precise information on the role of both isoenzymes. However, with dihydroxybenzoic acid as an artificial substrate, the Km values for S- and MB-COMT were similar, with values of 69.2 +/- 11.4 mumol l-1 and 72.2 +/- 9.2 mumol l-1, respectively. The proposed method is thought to be useful for the measurement of both S-COMT and MB-COMT activities, and would give us critical information on the role of meta...Continue Reading


Apr 5, 2002·Biomedical Chromatography : BMC·Nozomi AoyamaKazuhiro Imai
Aug 23, 2006·Analytical and Bioanalytical Chemistry·M Tsunoda
Nov 27, 2002·Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences·Pia Pihlavisto, Ilkka Reenilä
Nov 25, 2003·Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan·Kazuhiro Imai
Nov 5, 2008·Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan·M Tsunoda
Jan 13, 2004·Hypertension Research : Official Journal of the Japanese Society of Hypertension·M TsunodaKazuhiro Imai
Mar 31, 2005·Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences·Yoko HiranoKazuhiro Imai

Related Concepts

Catechol O-Methyltransferase
High Pressure Liquid Chromatography Procedure
Norepinephrine, (+, -)-Isomer
Rats, Wistar
Rats, Laboratory

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Lipidomics & Rhinovirus Infection

Lipidomics can be used to examine the lipid species involved with pathogenic conditions, such as viral associated inflammation. Discovered the latest research on Lipidomics & Rhinovirus Infection.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Torsion Dystonia

Torsion dystonia is a movement disorder characterized by loss of control of voluntary movements appearing as sustained muscle contractions and/or abnormal postures. Here is the latest research.

Archaeal RNA Polymerase

Archaeal RNA polymerases are most similar to eukaryotic RNA polymerase II but require the support of only two archaeal general transcription factors, TBP (TATA-box binding protein) and TFB (archaeal homologue of the eukaryotic general transcription factor TFIIB) to initiate basal transcription. Here is the latest research on archaeal RNA polymerases.

Alzheimer's Disease: MS4A

Variants within the membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease in genome-wide association studies. Here is the latest research on Alzheimer's disease and MS4A.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.