Total-body irradiation of postpubertal mice with (137)Cs acutely compromises the microarchitecture of cancellous bone and increases osteoclasts

• Published in: Radiation research 2009-03, Vol.171 (3), p.283
• Main Authors: Kondo, Hisataka, Searby, Nancy D, Mojarrab, Rose, Phillips, Jonathan, Alwood, Joshua, Yumoto, Kenji, Almeida, Eduardo A C, Limoli, Charles L, Globus, Ruth K
• Format: Article
• Language: English
• Subjects: Aging - pathology; Animals; Body Weight - radiation effects; Bone and Bones - diagnostic imaging; Bone and Bones - pathology; Bone and Bones - physiopathology; Bone and Bones - radiation effects; Bone Density - radiation effects; Bone Resorption - diagnostic imaging; Cesium Radioisotopes; Dose-Response Relationship, Radiation; Gamma Rays - adverse effects; Male; Mice; Organ Size - radiation effects; Osteoclasts - pathology; Osteoclasts - radiation effects; Time Factors; Tomography, X-Ray Computed; Whole-Body Irradiation - adverse effects
• ISSN: 0033-7587
• DOI: 10.1667/RR1463.1

Ionizing radiation can cause substantial tissue degeneration, which may threaten the long-term health of astronauts and radiotherapy patients. To determine whether a single dose of radiation acutely compromises structural integrity in the postpubertal skeleton, 18-week-old male mice were exposed to (137)Cs gamma radiation (1 or 2 Gy). The structure of high-turnover, cancellous bone was analyzed by microcomputed tomography (microCT) 3 or 10 days after irradiation and in basal controls (tissues harvested at the time of irradiation) and age-matched controls. Irradiation (2 Gy) caused a 20% decline in tibial cancellous bone volume fraction (BV/TV) within 3 days and a 43% decline within 10 days, while 1 Gy caused a 28% reduction 10 days later. The BV/TV decrement was due to increased spacing and decreased thickness of trabeculae. Radiation also increased ( approximately 150%) cancellous surfaces lined with tartrate-resistant, acid phosphatase-positive osteoclasts, an index of increased bone resorption. Radiation decreased lumbar vertebral BV/TV 1 month after irradiation, showing the persistence of cancellous bone loss, although mechanical properties in compression were unaffected. In sum, a single dose of gamma radiation rapidly increased osteoclast surface in cancellous tissue and compromised cancellous microarchitecture in the remodeling appendicular and axial skeleton of postpubertal mice.