Increased antineoplastic activity of combined hyperthermic and bleomycin treatments in an adenocarcinoma after glutathione depletion in vivo

Abstract

We have earlier shown that glutathione depletion, achieved by BSO administration, only marginally increases the antineoplastic activity of hyperthermic or bleomycin treatments in C3H mammary adenocarcinoma, grown subcutaneously in the hind paw of CBA mice. In this study we evaluated the role of glutathione depletion on the antineoplastic activity of combined hyperthermic and bleomycin treatments on the same tumour model system. The activity was recorded by determination of tumour volumes 12 days after treatment and by tumour regression frequencies. When hyperthermic and bleomycin treatments were combined, their respective effects on the 12-day volume values were additive, irrespective of treatment sequence and presence of BSO. However, BSO increased significantly the tumour regression frequencies accomplished by combined hyperthermic and bleomycin treatments, particularly of hyperthermic treatments given together with or 24 h after bleomycin. It is not possible to conclude, at present, whether this effect is caused by low glutathione levels.

Key Words:

• bleomycin
• hyperthermia
• BSO
• glutathione
• mammary adenocarcinoma