Modification of the thermal sensitivity of the murine foot and tumour by prior hypoxic treatment

Abstract

The response of Furth's murine mastocytoma to heat and the effect of prior heating and hypoxic treatment by clamping on the thermal sensitivity of the murine foot and the tumour were investigated. Two different-sized tumours, with average diameters of 3-4 mm and 7-8 mm were used. The tumour response to heat was evaluated by tumour growth (TG) time.

Thermotolerance developed in both the foot and tumour tissues by a prior heating for 5 or 10 min at 45°C. Hypoxic treatment resulted in dual effects on tumours. A 10 or 20 min hypoxic pretreatment increased thermal sensitivity of the tumour, while more than a 30 min hypoxic pretreatment induced thermotolerance. In contrast, a 20 min hypoxic treatment induced thermotolerance in the normal tissues. These results indicate that an appropriate period of prior hypoxic treatment may lead to a differential response between normal and tumour tissues.

Keywords::

• hypoxic treatment
• thermosensitivity
• thermotolerance
• mouse foot
• murine tumour