HPLC/tandem ion trap mass detector methods for determination of inosine monophosphate dehydrogenase (IMPDH) and thiopurine methyltransferase (TPMT).
The efficiency of Mycophenolate mofetil (MMF) and Azathioprine (AZA) as immunosuppressive agents depends on the activity of 2 enzymes, inosine monophosphate dehydrogenase (IMPDH) and thiopurine methyltransferase (TPMT) respectively. We present preliminary evaluation of nonradioactive methods that apply HPLC with ion-trap mass detection to measure the activities of IMPDH in peripheral blood mononuclear cells (PBMC) and TPMT in the erythrocytes (RBC). We found IMPDH activity of 0.9 +/- 0.2 nmol/hour/10(6) PBMC and TPMT activity of 19.9 +/- 4.7 nmol/hour/ml RBC in healthy subjects. These methods, following its further validation, could be useful for monitoring the activity in a clinical and experimental setting.
Kalsi
K
K
Heart Science Centre, Imperial College, London, UK.
Marinaki
A M
AM
Yacoub
M H
MH
Smolenski
R T
RT
D001379:Azathioprine / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007168:IMP Dehydrogenase / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007477:Ions; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D008780:Methyltransferases / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry*; D009173:Mycophenolic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D012107:Research Design
D007166:Immunosuppressive Agents; D007477:Ions; D007168:IMP Dehydrogenase; D008780:Methyltransferases; C022745:thiopurine methyltransferase; D009173:Mycophenolic Acid; D001379:Azathioprine