Urinary hypoxanthine and pseudouridine as indicators of tumor development in mesothelioma-transplanted nude mice.

A human mesothelioma was heterotransplanted to nude mice, and the urinary excretions of hypoxanthine, xanthine, pseudouridine, orotic acid, 7-methylguanine, and 1-methylhypoxanthine have been followed before and after the tumor transplantation. The compounds were measured by means of isotachophoresis, which has been found a rapid and precise method. The tumor reached maximum size within 30 days, and at this time a significantly increased excretion of pseudouridine and hypoxanthine was observed. Tumor growth was stopped by chemotherapy (vincristine, cyclophosphamide, prednisolone, and Adriamycin), and corresponding to this, a decrease occurred in both pseudouridine and hypoxanthine excretion to normal values.