The effect of ifosfamide on tumor oxygenation at different temperatures.

In MX1 human breast cancer xenografts grown on the hind paw of thymusaplastic nude mice the effect of ifosfamide on tumor oxygenation, tumor pH and the concentration of lactic acid have been determined at mean tumor temperatures of 32 degrees C, 37 degrees C and 41 degrees C. For histological studies tumors were shock-frozen or fixed with formalin or glutaraldehyde. Treatment with Ifosfamide (250 mg/kg b.w.) reduced intratumoral laser Doppler flow, oxygenation and pH. This suggests that ifosfamide or its metabolites may have an effect on tumor vasculature.