EFFECT OF INTRAPERITONEAL ATP ON TUMOR-GROWTH AND BONE-MARROW RADIATION TOLERANCE

Transplants of a spontaneous murine fibrosarcoma (FSaII) treated with intraperitoneal ATP were studied in vitro, and in both C3H and nu/nu m ice. Daily ATP treatment prolonged tumor volume doubling time in vivo and in vitro. Daily ATP treatments at the maximally tolerated dose (2 mmol/kg i.p.) did not significantly affect the pH or the PCr/P-i, or b eta ATP/P-i ratios (measured by MRS). In contrast to the reduced tumor growth rate, there was no change in bone marrow recovery after whole body irradiation. ATP is minimally toxic to animals at active dose lev els. It slows tumor growth rate without adversely affecting bone marro w radiation tolerance. ATP might therefore be useful as a biological m odifier of chemotherapy or radiation therapy.