Effect of microgravity simulated by mouse tail-suspension on bone
LI Yu1, ZHANG Xinhang2, ZHU Lei1, LI Jun1, and SUN Minlin1
1.Department of Orthopedics, Affiliated Hospital of Logistical College of Chinese People’s Armed Police Force, Tianjin 300162, China; 2. Department of Biochemistry and Molecular Biology of Logistical College of Chinese People’s Armed Police Force, Tianjin 300162,China
Abstract:Objective To study the effect of microgravity on the bone itself and metabolism.Methods 8-week-old widetype C57 mice were tail-suspended for 0, 2, 4, weeks. Related serum biochemical indices (Ca2+, ALP, BGP) were measured. Microstructure of bone was observed by micro-CT scanning. Three point bending test on the femurs by material testing machine helped to compare the changes of mechanical parameters. All the data were analysed.by SPSS18.0.Results Compared with control group, tail-suspended groups had a higher concentration in calcium in serum,the values of which were (2.134±0.08114) mmol/L, (2.261±0.07913) mmol/L, and (2.388±0.06112) mmol/L; lower levels of serum ALP and BGP, the difference was significant with a longer tail-suspension. The values of ALP was (4.598±0.4783) U/100 ml, (3.447±0.3930) U/100 ml, and (3.142±0.3280) U/100 ml; and the values of BGP were (8.529±0.5233) ng/ml, (8.108±0.3920) ng/ml, and (7.832±0.2821) ng/ml, which had statistically significant difference compared with control group (P<0.05).The scanning of femur showed obviously osteoporosis in tail-suspended mice. Compared with control group, number of bone trabecular reduced, the gap between them widened, thickness decreased simultaneously in the tail-suspended mice. Among which, BV/TV decreased most, the values of tailed-suspension for 2 and 4 weeks were 47.3% and 14.3% in the control group; There was a positive relationship between the osteoporosis and the time of tail-suspension. Mechanical parameters showed that the force decreased as well. Simulated microgravity promoted the loss of calcium in bone, mechanical properties of femurs of suspended-mice decreased, their capability of resistance to force decreasedas well. The forces to bone fracture in tailed-suspension for 0, 2 and 4 weeks were (6.220±0.482)mJ, (4.395±0.301)mJ, and (2.855±0.425)mJ, which had statistically significant difference compared with control group (P<0.05).Conclusions Simulated microgravity promotes the loss of calcium in bone, which can lead to osteoporosis, and the degree of that has a positive relationship to the time.
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LI Yu, ZHANG Xinhang, ZHU Lei, LI Jun, and SUN Minlin. Effect of microgravity simulated by mouse tail-suspension on bone. Med. J. Chin. Peop. Armed Poli. Forc., 2016, 27(4): 366-369.
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