Blood flow changes in transplanted mouse tumours and skin after mild hyperthermia

The influence of moderate hyperthermia on the vascular perfusion of four different tumour types and of normal mouse skin was investigated. The 86Rb extraction technique was used to measure changes in perfusion relative to total cardiac output, both during and after a one hour heat treatment at 42.5 degrees C. Perfusion of the SA FA tumour increased slightly during the first 30 minutes of heating but had returned to control values by the end of a 1 hour heating period. After heating, the relative perfusion of all four tumour types fell significantly below control values by 24 hours and remained low for 1-2 days (SA FA tumour) before returning to control values. Relative perfusion of normal skin was progressively increased during heating and remained elevated for 24 hours after the end of treatment before returning to control levels.