Protection by Interleukin 1 against Lung Toxicity Caused by Cyclophosphamide and Irradiation

Interleukin 1 has been shown to provide protection against the toxic effects of cyclophosphamide given in combination with localized irradiation of the lung. A single dose of 15 μg/kg interleukin 1 was given 24 h before cyclophosphamide (25-125 mg/kg) which was followed 1 day later by five daily exposures of 4.5 or 5.0 Gy, localized to the lung. Interleukin 1 significantly reduced early measurements of breathing rate for mice treated with high cyclophosphamide doses and irradiation, and at cyclophosphamide doses above 50 mg/kg, there was a significant reduction in the lethality from the combined treatment. At lower levels of cyclophosphamide, however, there seemed to be no effect.