Developments in cancer therapies and diagnostic techniques have improved the long-term survival of cancer patients. Certain cancer treatments, such as radiotherapy, often harm normal tissue as well as the specifically targeted cancer cells. High doses of radiation induce bone loss. This study investigated the effects of pentoxifylline (PTX) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham and irradiation (3 Gy, gamma-ray, IR) groups. The irradiated mice were treated for 12 weeks with vehicle, PTX (p.o.) or PTX (s.c.). Grip strength, uterus weight, serum alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) level were measured. Tibiae were analyzed using micro-computed tomography. There were no significant differences in the degree of grip strength, body weight and uterine weight between IR group and PTX-treated group. Treatment of PTX significantly preserved trabecular bone volume, trabecular number, trabecular separation and bone mineral density of proximal tibia metaphysic. The administration of PTX lowered serum TRAP in IR mice, suggesting that PTX can reduce the bone resorptive rate in mice. Our experimental data support the protective role of PTX against bone loss in irradiated mice. Based on the findings of this study, development of PTXbased treatments is anticipated to address bone loss after radiotherapy. Prospective dose escalation studies are required to determine the appropriate dosage of PTX.

Introduction
Materials and Methods
    실험동물 및 방사선 조사
    실험군의 분류 및 시험물질 투여
    악력측정, 시료 채취 및 혈청생화학적 측정
    미세 전산화 단층 촬영(micro-computed tomography,μCT)
    자료통계 및 분석
Results
Discussion
References

• Sung-Ho Kim(College of Veterinary Medicine, Chonnam National University) Corresponding author