The effect of hyperthermia on micronucleus induction by mutagens in mice.
We administered mitomycin C (0.5 mg/kg) intraperitoneally to hyperthermic-treated mice and examined the effect of hyperthermia on micronucleus induction. Hyperthermia enhanced micronucleus induction. The timing of chemical administration relative to the start of hyperthermic treatment (37 degrees C ambient temperature) influenced micronucleus frequency, and the effect was greatest 2 h after the start of hyperthermic treatment. But the hyperthermic treatment did not change the time course of micronucleus induction. In addition, we investigated the effect of hyperthermia on micronucleus induction by chemicals with different modes of action, i.e., alkylating agents (mitomycin C at 0.1-0.5 mg/kg, cyclophosphamide at 1.25-10 mg/kg), a spindle poison (colchicine at 0.05-1.0 mg/kg), and an antimetabolite (5-fluorouracil at 2.5-50 mg/kg). Hyperthermia enhanced only the clastogenicity of alkylating agents.
Asanami
S
S
Naruto Research Institute, Otsuka Pharmaceutical Factory, Tokushima, Japan. asanamsy@otsukakj.co.jp
Shimono
K
K
D000477:Alkylating Agents / Q000633:toxicity; D000818:Animals; D000963:Antimetabolites / Q000633:toxicity; D002467:Cell Nucleus / Q000235:genetics*; D003078:Colchicine / Q000633:toxicity; D003432:Cross-Linking Reagents / Q000633:toxicity; D003520:Cyclophosphamide / Q000633:toxicity; D005334:Fever / Q000235:genetics*; D005472:Fluorouracil / Q000633:toxicity; D006979:Hyperthermia, Induced; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D015162:Micronucleus Tests; D016685:Mitomycin / Q000633:toxicity; D009153:Mutagens / Q000633:toxicity*; D013997:Time Factors
D000477:Alkylating Agents; D000963:Antimetabolites; D003432:Cross-Linking Reagents; D009153:Mutagens; D016685:Mitomycin; D003520:Cyclophosphamide; D003078:Colchicine; D005472:Fluorouracil