The purpose of this study was to clarify the safety and the effects of thermal therapy on skeletal muscle atrophy with leukemia by using model rats. Thirty Wistar rats (4 weeks old; male) were used. The rats were divided randomly into three groups; Control (n = 10), leukemia (L, n=10), and leukemia plus thermal therapy groups (L+T, n = 10). Leukemia was induced by injection of 7,12-dimethylbenz-[a]anthracene in the L and L+T groups, injection was carried out 4 times with 10 days interval. Infrared therapy device was used for thermal therapy on hindlimbs in the L+T groups. Thermal therapy was begun after end of the injection and was performed for 4 weeks (40min/day, once per 2 days). Weight, erythrocyte sedimentation rate (ESR), hematocrit, and number of white blood cell (WBC), plasma concentrations of tumor necrosis factor alpha (TNFα), plasma concentrations of LDL receptor related with 11 binding repeats (LR11), muscle RING fiber protein 1 (MuRF1), heat shock protein 72 (HSP72) and muscle fiber diameter were measured. As the result, although HSP72 level was increased in the L+T group compared with the L group, MuRF1 level and muscle fiber diameter were not changed after thermal therapy. The change of progress of leukemia by thermal therapy was not observed from the results of weight, ESR, he matocrit, WBC, TNFα, LR11. In conclusion, thermal therapy on skeletal muscle might not prevent and recover the muscle atrophy with leukemia, though thermal therapy on skeletal muscle do not affect a progress of leukemia.
