[Effects of simulated weightlessness on ALP, ACP, collagen I, and biomechanics of hind-limb bones in rats].

OBJECTIVE

To investigate effects of 3 weeks simulated weightlessness on biomechanical parameters, alkaline phosphatase (ALP), acid phosphatase (ACP) and collagen I of hind-limb bones in tail-suspended rats.

METHOD

Fourteen male SD rats were divided equally into control group (CON) and experimental group; tail-suspended (TS) was used to simulate weightlessness. After 3 weeks tail-suspension, biomechanical parameters of femur were measured; ALP, ACP and collagen I of tibia were observed.

RESULT

Elastic load, maximum load, and bending rigidity coefficient decreased significantly (P<0.01), while the maximum deformation and bending toughness coefficient increased markedly (P<0.01 or P<0.05). Morphological results showed that ALP declines significantly in TS group, ACP and type I collagen increased significantly in TS group.

CONCLUSION

After tail-suspension for 3 weeks, growth of rat's weight bearing bones are suppressed, biomechanical capability declines, and collagen I metabolism becomes disordered.