EFFECT OF HYPERTONIC GLUCOSE IN THERMOTOLERANT RAT BT(4)AN GLIOMAS TREATED WITH COMBINED HYPERTHERMIA AND BCNU IN-VIVO

The influence of hypertonic glucose i.p. on development of thermotoler ance and thermochemosensitivity with BCNU in thermotolerant tumours, a nd on intratumoural pH alterations in previously unheated and thermoto lerant tumours, was investigated in BT(4)An tumours grown on the hind foot of ED IX rats. Thermotolerance was induced with local waterbath h yperthermia (44 degrees C/45 min) 24 h before start of test treatment. Hypertonic glucose immediately after priming hyperthermia did not inh ibit development of thermotolerance, despite a significant reduction o f pH by glucose. The pH reduction was less in thermotolerant tumours. Glucose administered before treatment of thermotolerant tumours did no t change the growth rate of tumours treated with hyperthermia (44 degr ees C/45 min), BCNU (20 or 25 mg/kg i.p.) or thermochemotherapy with a low or high dose BCNU (10 or 20 mg/kg), in contrast to previous resul ts, where glucose enhanced thermochemosensitivity of non-thermotoleran t tumours.