[The microenvironment of tumor cells and the antitumor effect of hyperthermia]

Intravenous infusion of 20% solution of glucose (80 mg/kg of body mass per 1 min) resulted in considerable changes in microenvironment of tumor cells: by the 90th-120th min of infusion there was a decrease in pH, pO2, blood flow inhibition, an increase in the relative number of cells in the S-phase of the mitotic cycle in a tumor. There was no increase in tumor ATP and glucose up to the values at which these substance could enhance thermoresistance, a situation being rather favorable for realizing a damaging effect of hyperthermia. The use of hyperglycemia in the above regimen prior to MWF-hyperthermia enhanced 2-3 times its antitumor effect on the model of subcutaneously transplanted Guéren carcinoma and Pliss lymphosarcoma. Glucose at the concentration of 5-0 mmol enhanced the thermosensitivity of L-1210 cells. The results indicated the efficacy of hyperglycemia combined with hyperthermia.