Continuous and non-invasive quantification of heat-induced changes in blood flow in the skin and RIF-1 tumour of mice by laser Doppler flowmetry

The changes in blood flow in the skin and in the periphery of RIF-1 tumours of C3H mice could be monitored continuously during heating with the use of the laser doppler flowmetry. The laser probe was placed gently on the skin or tumour surface and the change in blood flow was quantified from the output signal from the monitor during the heating of the tissues with temperature-controlled water. The blood flow in the tumour increased significantly during the first 20-30 min of heating at 42.5-44.5 degrees C and then began to decline during the second half of one hour of heating. The skin blood flow either continuously increased or remained elevated during 1 h heating at 42.5-44.5 degrees C. These results were generally similar to the previous reports on the heat-induced changes in blood flow in the skin and tumours measured by other methods.