Oxygen cathode measurements and radiation response in tumour-bearing mice treated with misonidazole.
Direct measurements using 200 micron oxygen cathode electordes have been made in tumour and subcutaneous tissues of anaesthetized C3H mice treated with misonidazole. In air-breathing animals a six-fold increase in tumour oxygen cathode readings was observed by 23 min after i.p. injection of misonidazole at 0.5 mg/g body weight. A similar rise, but of 2.5 times, was observed for the subcutaneous tissues. Comparison of tumour oxygen readings for drug-treated and control mice breathing 100% O2 at different pressures showed markedly increased levels for the drug-treated animals. Tumour response to radiation was measured for 250 kV X-rays and 15 MeV electrons. In each case, when a dose of radiation was combined with pre-treatement with misonidazole an increased radiation response was observed when compared with the same dose of radiation given alone. At the highest dose (40 Gy) there was a suggestion of an increased normal tissue reaction. The significance of the measurements is discussed.
D000230:Adenocarcinoma / Q000378:metabolism / Q000532:radiotherapy; D000818:Animals; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism* / Q000532:radiotherapy; D051379:Mice; D008809:Mice, Inbred C3H; D009593:Nitroimidazoles / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors
D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents