High body temperature induces micronuclei in mouse bone marrow.
The mouse micronucleus test was conducted to investigate the effect of high body temperature on micronucleus induction. Group of 10 male ddY mice were exposed to 30 degrees C for 1, 3 or 6 h, 37 degrees C for 0.5, 1, 2, 3 or 4 h, and 40 degrees C for 1 or 2 h. Bone marrow cells were sampled 24 h after heat exposure. Exposure of mice to 37 degrees C for 3 or 4 h and 40 degrees C for 1 or 2 h raised body temperature to approximately 40.5 degrees C and produced statistically significant increases in micronucleated polychromatic erythrocyte frequencies (8.1 +/- 4.5, 6.0 +/- 2.1, 5.3 +/- 3.3, 7.5 +/- 2.9%, respectively; control frequencies, 2.0 +/- 1.1%). In addition, about 25% of the induced micronuclei were relatively large (diameter of micronucleus > or = 1/4 diameter of cytoplasm). These results suggest that body temperatures of 39.5 degrees C or higher for more than 30 min induce micronuclei in bone marrow cells, and one possible mechanism is disturbance of the mitotic apparatus.
Asanami
S
S
Naruto Research Institute, Otsuka Pharmaceutical Factory, Inc., Tokushima, Japan.
Shimono
K
K
D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D001853:Bone Marrow / Q000187:drug effects* / Q000502:physiology; D002467:Cell Nucleus / Q000187:drug effects / Q000502:physiology*; D003078:Colchicine / Q000633:toxicity; D006358:Hot Temperature; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D015162:Micronucleus Tests; D016685:Mitomycin / Q000633:toxicity; D009153:Mutagens / Q000633:toxicity; D012007:Rectum / Q000502:physiology; D013997:Time Factors
D009153:Mutagens; D016685:Mitomycin; D003078:Colchicine