THE IMPORTANCE OF CHOICE OF ANESTHETICS IN STUDYING RADIATION EFFECTSIN THE 9L RAT GLIOMA

In the present study we demonstrate that the glycolysis of the tumour 9L glioma, in vivo, may be manipulated with ketamine/xylazine combinat ions of anaesthetics. Xylazine alone or in combination with ketamine c auses hyperglycaemia which is enhanced by glucose injections. Intracel lular tumour pH is acidified when glucose is administered with ketamin e/xylazine. However, the combination of inorganic phosphate and insuli n with ketamine/xylazine and glucose caused an alkaline shift in the t umour pH as measured by P-31 NMR. The anaesthetic combination of ketam ine/acepromazine did not produce alterations in blood glucose or in tu mour pH status as detected by P-31 NMR spectroscopy. These results dem onstrate dramatic effects of ketamine/xylazine on the acidification or alkalinisation of the cells of 9L glioma. These altered metabolic sta les are of potential therapeutic importance. The choice of xylazine al one would be useful for chemotherapy and hyperthermia modalities, both known to be dependent upon glucose metabolism and resultant acidifica tion.