Bone Loss Induced by Simulated Microgravity, Ionizing Radiation and/or Ultradian Rhythms in the Hindlimbs of Rats.

Ya Nan ZHANG; Wen Gui SHI; He LI; Jun Rui HUA; Xiu FENG; Wen Jun WEI; Ju Fang WANG; Jin Peng HE; Su Wen LEI

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Bone Loss Induced by Simulated Microgravity, Ionizing Radiation and/or Ultradian Rhythms in the Hindlimbs of Rats.

Author: Ya Nan ZHANG ¹ ; Wen Gui SHI ² ; He LI ² ; Jun Rui HUA ¹ ; Xiu FENG ¹ ; Wen Jun WEI ² ; Ju Fang WANG ¹ ; Jin Peng HE ¹ ; Su Wen LEI ³
Author Information

1. Key Laboratory of Space Radiobiology of Gansu Province & CAS Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China.
2. Key Laboratory of Space Radiobiology of Gansu Province & CAS Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; University of Chinese Academy of Sciences, Beijing 100049, China.
3. Office of Health Standards, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Publication Type:Journal Article
Keywords: Bone loss; Microgravity; Radiation; Ultradian rhythms
MeSH: Animals; Biomechanical Phenomena; Bone Density; physiology; Bone Resorption; etiology; metabolism; Femur; metabolism; Hindlimb Suspension; Rats, Sprague-Dawley; Tibia; metabolism; Ultradian Rhythm; Weightlessness Simulation; adverse effects; X-Rays; adverse effects
From: Biomedical and Environmental Sciences 2018;31(2):126-135
CountryChina
Language:English
Abstract: OBJECTIVE:To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.
METHODS:Sprague Dawley (SD) rats were randomly divided into a baseline group, a control group, a hindlimb suspension group, a radiation group, a ultradian rhythms group and a combined-three-factor group. After four weeks of hindlimb suspension followed by X-ray exposure and/or ultradian rhythms, biomechanical properties, bone mineral density, histological analysis, microstructure parameters, and bone turnover markers were detected to evaluate bone loss in hindlimbs of rats.
RESULTS:Simulated microgravity or combined-three factors treatment led to a significant decrease in the biomechanical properties of bones, reduction in bone mineral density, and deterioration of trabecular parameters. Ionizing radiation exposure also showed adverse impact while ultradian rhythms had no significant effect on these outcomes. Decrease in the concentration of the turnover markers bone alkaline phosphatase (bALP), osteocalcin (OCN), and tartrate-resistant acid phosphatase-5b (TRAP-5b) in serum was in line with the changes in trabecular parameters.
CONCLUSION:Simulated microgravity is the main contributor of bone loss. Radiation also results in deleterious effects but ultradian rhythms has no significant effect. Combined-three factors treatment do not exacerbate bone loss when compared to simulated microgravity treatment alone.