administered as a continuous intravenous infusion to pediatric patients is metabolized to the novel metab olite 8-hydroxy-thioguanine.
The spectrum of thiopurine metabolites that can be measured by our assay methodology (thioguanine
, 8-hydroxymercaptopurine, mercaptopurine, 8hydroxythioguanine, thioxanthine, and thiouric acid plus methylthioguanine and the methyhnercaptopurine metabolites) are safe from oxidation and stable for several days when back-extracted or reconstituted in 0.1 mol/L HCl.
Kinetics of mercaptopurine and thioguanine
nucleotides in renal transplant recipients during azathioprine treatment.
MPNs predominated over thioguanine and MeMPN concentrations at 6 h, but at 20 h, MPN concentrations were lower and MeMPN concentrations were higher relative to concentrations at 6 h.
Methylation of mercaptopurine, thioguanine, and their nucleotide metabolites by heterologously expressed human thiopurine S-methyltransferase.
A clinically useful ion-pairing high-performance liquid chromatographic assay for the monophosphate metabolites of thioguanine and mercaptopurine in human neoplastic cells.
High-performance liquid chromatographic assay of the methyl and nucleotide metabolites of 6 mercaptopurine: quantification of red blood cell 6 thioguanine nucleotide, 6 thioinosinic acid and methylmercaptopurine metabolites in a single sample.
A reversed phase high performance liquid chromatographic approach in determining total red blood cell concentrations of 6 thioguanine, 6 mercaptopurine, methylthioguanine and methylmercaptopurine in a patient receiving thiopurine therapy.
To this end, intracellular thioguanine nucleotides (TGN) serve as the most informative measure of systemic exposure.
Most studies have used RBC concentrations of TGN as the measure of systemic exposure to active metabolites, with no further differentiation of the mono-, di-, and triphosphate nucleotides of thioguanine. In nucleated cells (e.g., leukocytes, lymphoblasts), these thioguanine nucleotides are incorporated into DNA and RNA-which is considered an important mechanism of cytotoxicity.