caa a22 4500 475818660 CHVBK 20180406123816.0 cr unu---uuuuu 170329e20000701xx s 000 0 eng 10.1007/s002280000137 doi (NATIONALLICENCE)springer-10.1007/s002280000137 Methylation of 6-mercaptopurine and 6-thioguanine by thiopurine S-methyltransferaseA comparison of activity in red blood cell samples of 199 blood donors [Elektronische Daten] A comparison of activity in red blood cell samples of 199 blood donors [T. Kröplin, H. Iven] 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−1Hb 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. Springer-Verlag Berlin Heidelberg, 2000 Key words 6-Thioguanine nationallicence 6-Mercaptopurine nationallicence Thiopurine S-methyltransferase nationallicence Kröplin T. Department of Experimental and Clinical Pharmacology and Toxicology, Lübeck Medical University, Ratzeburger Allee 160, D-23538 Lübeck, Germany e-mail: iven@medinf.mu-luebeck.de Tel.: +49-451-5002682; Fax: +49-451-5006573, DE aut Iven H. Department of Experimental and Clinical Pharmacology and Toxicology, Lübeck Medical University, Ratzeburger Allee 160, D-23538 Lübeck, Germany e-mail: iven@medinf.mu-luebeck.de Tel.: +49-451-5002682; Fax: +49-451-5006573, DE aut https://doi.org/10.1007/s002280000137 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002280000137 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kröplin T. Department of Experimental and Clinical Pharmacology and Toxicology, Lübeck Medical University, Ratzeburger Allee 160, D-23538 Lübeck, Germany e-mail: iven@medinf.mu-luebeck.de Tel.: +49-451-5002682; Fax: +49-451-5006573, DE aut NATIONALLICENCE 700 1- Iven H. Department of Experimental and Clinical Pharmacology and Toxicology, Lübeck Medical University, Ratzeburger Allee 160, D-23538 Lübeck, Germany e-mail: iven@medinf.mu-luebeck.de Tel.: +49-451-5002682; Fax: +49-451-5006573, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer