www.jrpr.org 253 ABSTRACT Original Research Received December 15, 2015 Revision May 20, 2016 Accepted July 8, 2016 Corresponding author: Sung-Ho Kim College of Veterinary Medicine, Chonnam National University, 77, Yongbong-ro, Buk-gu, Gwangju 61186, Korea Tel: +82-62-530-2837 Fax: +82-62-530-2841 E-mail: shokim@jnu.ac.kr This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ licenses/by-nc/4.0) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2016 The Korean Association for Radiation Protection Evaluation of the Efcacy of Zoledronic Acid and Amifostine on Radiation-induced Bone Loss in Mice Jinwook Kim 1 , Sueun Lee 1 , Sohi Kang 1 , Changjong Moon 1 , Jong-Choon Kim 1 , Uhee Jung 2 , Sung-Kee Jo 2 , Jong-Sik Jang 3 , Sung-Ho Kim 1, * 1 College of Veterinary Medicine, Chonnam National University, Gwangju; 2 Advanced Radiation Technology Institute, Jeungeup; 3 College of Ecology and Environmental Science, Kyungpook National University, Sangju, Korea Background: Tis study investigated the efects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. Materials and Methods: C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). Te irradiated mice were treated for 12 weeks with vehicle, amifos- tine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Results and Discussion: Treatment of ZA (100 μg · kg -1 · week -1 ) signifcantly preserved trabec- ular bone volume, trabecular thickness, trabecular number, trabecular separation, bone min- eral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. Te administration of ZA for 12 weeks lowered serum ALP and TRAP lev- els in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No difer- ences were apparent between the amifostine-treated group and the irradiation control group. Conclusion: Te results indicate that ZA can prevent radiation-induced bone loss in mice. Keywords: Bone loss, Micro-computed tomography, Radiation, Zoledronic acid pISSN 2508-1888 | eISSN 2466-2461 Introduction Developments in cancer therapies and diagnostic techniques have improved the long-term survival of cancer patients [1]. There has been a corresponding increase in the prevalence of specific and chronic side effects of cancer treatment among survi- vors. Certain cancer treatments, such as radiotherapy, often harm normal tissue as well as the specifically targeted cancer cells [2]. The underlying mechanism of these adverse effects and the prognoses associated with them deserve greater research attention. High doses of radiation induce bone loss. Irradiation of bone principally causes atro- phy accompanied by compromised function and structure of the bone tissue, but does not result in alterations of the bone size. Changes in vasculature, composition of bone matrix, and cellular components are putative etiologies of irradiation-induced damage in bone [3]. Irradiation of bone has also been associated with fractures [4]. Osteoporo- sis is a public health concern with a heavy financial burden on both society and pa- tients [5]. Drugs for osteoporosis aim to augment the bone regeneration process as op- posed to the bone resorption process. Inhibitors of bone resorption include estrogen, calcitonin, bisphosphonates, calcium, vitamin D, and raloxifene. Accelerators of bone Journal of Radiation Protection and Research 2016;41(3):253-259 https://doi.org/10.14407/jrpr.2016.41.3.253 JRP R