Renal damage in mice after treatment with cisplatinum alone or in combination with X-irradiation

Functional kidney damage in mice was measured (using clearance of 51Cr-EDTA) from 1 to 39 weeks after treatment with single doses of cisplatinum (c-DDP), X rays, or their combination. After c-DDP alone renal damage was observed within 1 week. From 1 to 7 weeks there was recovery of function after low drug doses but after doses in excess of 6 mg/kg some damage persisted. After irradiation alone there was no measurable change in function for 20 weeks. Beyond this time there was a dose dependent and progressive deterioration of function. c-DDP given before or after irradiation caused more damage than either agent alone. During the first 20 weeks independent toxicities accounted for most of this effect but at later times modification of radiation damage possibly contributed. The greatest enhancements were observed when c-DDP was given 1/2 hour before to 1 day after irradiation (Dose Modifying Factor, DMF, 1.3). c-DDP given 3 to 4 weeks before X rays caused only a slight enhancement of damage (DMF 1.1).