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Updated: Jul 20, 2026
Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Rat liver and kidney catechol-O-methyltransferase activity measured by high-performance liquid chromatography with
Makoto Tsunoda1, Kazuko Takezawa, Mayumi Masuda
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Japan.
Abstract:
We have previously reported a highly sensitive method for the measurement of catechol-O-methyltransferase (COMT) activities in rat erythrocytes with norepinephrine (NE), an endogenous native substrate, using high-performance liquid chromatography (HPLC)-fluorescence or peroxyoxalate chemiluminescence reaction detection. Applying this method to COMT activities in rat liver and kidney, known to have the highest activities of all organs, the optimum reaction conditions were investigated. Under the optimum conditions, soluble (S)-COMT and membrane-bound (MB)-COMT activities in rat liver, with NE as a substrate, were 2.17 +/- 0.33 and 0.16 +/- 0.02 nmol/min/mg protein (n = 5), respectively. In rat kidney, S-COMT and MB-COMT activities were 1.81 +/- 0.20 and 0.079 +/- 0.009 nmol/min/mg protein (n = 5), respectively. Since liver and kidney play important roles in inactivating catecholamines, using the proposed method would yield critical information to delineate the role of metabolism of catecholamines in rat tissues.
