6-Thioguanine Metabolism in Human Erythrocytes

Abstract

Thiopurines must undergo enzymatic conversion into a variety of nucleotide derivatives in order to display cytotoxic activity [1]; the major ones in human erythrocytes are the 6-thioguanine nucleotides [2]. These compounds derive from the immunosuppressive agent azathioprine as well as from the cytotoxic drugs 6-thioguanine and 6-mercaptopurine [3]. Increased concentrations of erythrocyte 6-thioguanine nucleotides have been related to neutropenia in leukaemic children receiving chronic 6-mercaptopurine chemotherapy [4]. Moreover, 6-thioguanine nucleotides are an index of bone marrow failure in adults subjected to azathioprine immunosuppression [5].