[Intensification of tumor acidification in artificial hyperglycemia using inorganic phosphate]

Using pH glass microelectrodes with maximum diameters of 100-200 micron (sensitivity 55-60 mV/pH unit at 37 degrees C; drift 0,001-0,002 pH unit/hr) pH has been measured in transplanted tumors (Guerin carcinoma, Pliss lymphosarcoma, Krocker sarcoma) and in muscle under artificial hyperglycaemia. We showed the ability of inorganic phosphate to amplify the process of acidification of the tumor tissue under these conditions. Using inorganic phosphate it was possible to reach pH values of 4,6-5,0 in different experimental tumors.