T Kröplin1, H Iven. 1. Department of Experimental and Clinical Pharmacology and Toxicology, Lübeck Medical University, Germany.
Abstract
OBJECTIVES: To compare 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) as substrates for the methylation reaction catalysed by the enzyme thiopurine S-methyltransferase (TPMT). METHODS: TPMT activity in haemolysed red blood cells of healthy blood donors was determined twice, using the same experimental setting and equal molar concentrations of 6-TG and 6-MP as substrates. After extraction, the reaction products 6-methyl-TG and 6-methyl-MP were quantified using specific high-performance liquid chromatography procedures. RESULTS: The medians of the TPMT activities from 199 blood donors were 54.4 nmol 6-MTG g(-1)Hb h(-1) when measured with 6-TG as the substrate and 35.8 nmol 6-MMP g(-1) Hb h(-1) when measured with 6-MP. The correlation coefficient for the 199 pairs of values was 0.8695. On average, TPMT activity was 34% lower with 6-MP as substrate than with 6-TG as substrate.
OBJECTIVES: To compare 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) as substrates for the methylation reaction catalysed by the enzyme thiopurine S-methyltransferase (TPMT). METHODS:TPMT activity in haemolysed red blood cells of healthy blood donors was determined twice, using the same experimental setting and equal molar concentrations of 6-TG and 6-MP as substrates. After extraction, the reaction products 6-methyl-TG and 6-methyl-MP were quantified using specific high-performance liquid chromatography procedures. RESULTS: The medians of the TPMT activities from 199 blood donors were 54.4 nmol 6-MTG g(-1)Hb h(-1) when measured with 6-TG as the substrate and 35.8 nmol 6-MMP g(-1) Hb h(-1) when measured with 6-MP. The correlation coefficient for the 199 pairs of values was 0.8695. On average, TPMT activity was 34% lower with 6-MP as substrate than with 6-TG as substrate.
Authors: Imke Tiede; Gerhard Fritz; Susanne Strand; Daniela Poppe; Radovan Dvorsky; Dennis Strand; Hans Anton Lehr; Stefan Wirtz; Christoph Becker; Raja Atreya; Jonas Mudter; Kai Hildner; Brigitte Bartsch; Martin Holtmann; Richard Blumberg; Henning Walczak; Heiko Iven; Peter R Galle; Mohammad Reza Ahmadian; Markus F Neurath Journal: J Clin Invest Date: 2003-04 Impact factor: 14.808
Authors: Andres J Yarur; Maria T Abreu; Amar R Deshpande; David H Kerman; Daniel A Sussman Journal: World J Gastroenterol Date: 2014-04-07 Impact factor: 5.742