1. Bach JF, Strom T (1985) Thiopurines (6-mercaptopurine, azathioprine, thioguanine). In: Newberger A, Tatum EL (eds) The mode of action of immunosuppressive agents. Elsevier, Amsterdam, pp 105?174
2. Breter HJ, Zahn RK (1979) Quantitation of intracellular metabolites of (35 S)-6-mercaptopurine in L 5178 Y cells grown in time-course incubates. Cancer Res 39: 3744?3748
3. Bronk JR, Lister N, Shaw MI (1988) Transport and metabolism of 6-thioguanine and 6-mercaptopurine in mouse small intestine. Clin Sci 74: 629?638
4. Chan GLC, Cannafax DM, Erdmann GR, Simmons RL (1988) Disposition of azathioprine metabolites, thiouric acid and 6-mercaptopurine, in renal transplant patients. Clin Pharmacol Ther 43: 179
5. Ding TL, Benet LZ (1979) Comparative bioavailability and pharmacokinetic studies of azathioprine and 6-mercaptopurine in the rhesus monkey. Drug Metab Dispos 7: 373?377